1
|
Cardé RT. Wind Tunnels and Airflow-Driven Assays: Methods for Establishing the Cues and Orientation Mechanisms That Modulate Female Mosquito Attraction to Human Hosts. Cold Spring Harb Protoc 2024; 2024:pdb.over107675. [PMID: 38190632 DOI: 10.1101/pdb.over107675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Understanding how female mosquitoes find a prospective host is crucial to developing means that can interfere with this process. Many methods are available to researchers studying cues and orientation mechanisms that modulate female mosquito attraction to hosts. Behaviors that can be monitored with these assays include activation, taking flight, upwind flight along an odor plume (optomotor anemotaxis), close approach to the stimulus (including hovering), and landing. Video recording can three-dimensionally document flight tracks and can correlate overall distribution patterns and moment-to-moment movements with odor contact and the presence of nearby cues such as a visual target. Here, we introduce mosquito host-seeking behaviors and methods to study them: wind tunnels (which allow orientation in free-flight), airflow-driven assays (using either tethered mosquitoes or small assay chambers that permit flight but also often dictate walking orientation), and still-air assays (wherein in odor concentration and spatial distribution are the orientation cues). We also describe factors that affect the assays and provide assay design considerations.
Collapse
Affiliation(s)
- Ring T Cardé
- Department of Entomology, University of California, Riverside, California 92521, USA
| |
Collapse
|
2
|
Weiss L, McBride CS. Mosquitoes as a model for understanding the neural basis of natural behaviors. Curr Opin Neurobiol 2024; 87:102897. [PMID: 39002351 DOI: 10.1016/j.conb.2024.102897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 07/15/2024]
Abstract
Mosquito behaviors have been the subject of extensive research for over a century due to their role in the spread of human disease. However, these behaviors are also beginning to be appreciated as excellent models for neurobiological research in their own right. Many of the same behaviors and sensory abilities that help mosquitoes survive and reproduce alongside humans represent striking examples of generalizable phenomena of longstanding neurobiological interest. In this review, we highlight four prominent examples that promise new insight into (1) precise circadian tuning of sensory systems, (2) processing of complex natural odors, (3) multisensory integration, and (4) modulation of behavior by internal states.
Collapse
Affiliation(s)
- Lukas Weiss
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA; Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Carolyn S McBride
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA; Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
| |
Collapse
|
3
|
Stupski SD, van Breugel F. Wind gates olfaction-driven search states in free flight. Curr Biol 2024:S0960-9822(24)00912-6. [PMID: 39067453 DOI: 10.1016/j.cub.2024.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/08/2024] [Accepted: 07/01/2024] [Indexed: 07/30/2024]
Abstract
For organisms tracking a chemical cue to its source, the motion of their surrounding fluid provides crucial information for success. Swimming and flying animals engaged in olfaction-driven search often start by turning into the direction of an oncoming wind or water current. However, it is unclear how organisms adjust their strategies when directional cues are absent or unreliable, as is often the case in nature. Here, we use the genetic toolkit of Drosophila melanogaster to develop an optogenetic paradigm to deliver temporally precise "virtual" olfactory experiences for free-flying animals in either laminar wind or still air. We first confirm that in laminar wind flies turn upwind. Furthermore, we show that they achieve this using a rapid (∼100 ms) turn, implying that flies estimate the ambient wind direction prior to "surging" upwind. In still air, flies adopt a remarkably stereotyped "sink and circle" search state characterized by ∼60° turns at 3-4 Hz, biased in a consistent direction. Together, our results show that Drosophila melanogaster assesses the presence and direction of ambient wind prior to deploying a distinct search strategy. In both laminar wind and still air, immediately after odor onset, flies decelerate and often perform a rapid turn. Both maneuvers are consistent with predictions from recent control theoretic analyses for how insects may estimate properties of wind while in flight. We suggest that flies may use their deceleration and "anemometric" turn as active sensing maneuvers to rapidly gauge properties of their wind environment before initiating a proximal or upwind search routine.
Collapse
Affiliation(s)
- S David Stupski
- Integrative Neuroscience Program, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA; Ecology Evolution and Conservation Biology Program, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA; Department of Mechanical Engineering, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA
| | - Floris van Breugel
- Integrative Neuroscience Program, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA; Ecology Evolution and Conservation Biology Program, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA; Department of Mechanical Engineering, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA.
| |
Collapse
|
4
|
Stupski SD, van Breugel F. Wind Gates Olfaction Driven Search States in Free Flight. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.30.569086. [PMID: 38076971 PMCID: PMC10705368 DOI: 10.1101/2023.11.30.569086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
For organisms tracking a chemical cue to its source, the motion of their surrounding fluid provides crucial information for success. Swimming and flying animals engaged in olfaction driven search often start by turning into the direction of an oncoming wind or water current. However, it is unclear how organisms adjust their strategies when directional cues are absent or unreliable, as is often the case in nature. Here, we use the genetic toolkit of Drosophila melanogaster to develop an optogenetic paradigm to deliver temporally precise "virtual" olfactory experiences for free-flying animals in either laminar wind or still air. We first confirm that in laminar wind flies turn upwind. Furthermore, we show that they achieve this using a rapid (∼100 ms) turn, implying that flies estimate the ambient wind direction prior to "surging" upwind. In still air, flies adopt remarkably stereotyped "sink and circle" search state characterized by ∼60°turns at 3-4 Hz, biased in a consistent direction. Together, our results show that Drosophila melanogaster assess the presence and direction of ambient wind prior to deploying a distinct search strategy. In both laminar wind and still air, immediately after odor onset, flies decelerate and often perform a rapid turn. Both maneuvers are consistent with predictions from recent control theoretic analyses for how insects may estimate properties of wind while in flight. We suggest that flies may use their deceleration and "anemometric" turn as active sensing maneuvers to rapidly gauge properties of their wind environment before initiating a proximal or upwind search routine.
Collapse
|
5
|
Richards SL, Sousan S, Murray W, White A, Peyton K, Slade R. Development of novel compact wind tunnel for testing efficacy of insecticide formulated products in mosquitoes. PEST MANAGEMENT SCIENCE 2024; 80:3140-3148. [PMID: 38345320 DOI: 10.1002/ps.8018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/04/2024] [Accepted: 02/08/2024] [Indexed: 02/22/2024]
Abstract
BACKGROUND Ultra-low volume (ULV) space sprays aerosolize insecticide formulated products (FP) to contact flying mosquitoes, while barrier sprays expose mosquitoes to FP residue on vegetation and other surfaces. Centers for Disease Control and Prevention bottle bioassays used to assess insecticide resistance are based on residual active ingredient (AI) exposure and do not directly relate to FP efficacy. The current pilot study developed a novel compact wind tunnel for mosquito exposure to FP. Caged Aedes albopictus and Culex pipiens/quinquefasciatus were exposed to undiluted Biomist®3 + 15 FP (permethrin AI) or air (control) within the wind tunnel, transferred to new cages, and held in a 28 °C incubator. Separate mosquitoes were exposed to residual permethrin AI (8 μg mL-1) in bottle bioassays. Mortality was monitored 15, 30, 60, and 120 min post-exposure. RESULTS Chi-square tests (P < 0.05) showed significantly higher mortality in Aedes compared to Culex populations for most time points in both bioassay and wind tunnel exposure groups. As expected, mosquitoes exposed to Biomist®3 + 15 showed higher mortality rates than bottle bioassay exposure to permethrin. Two Culex colonies resistant to permethrin in bottle bioassays were susceptible to Biomist®3 + 15 in the wind tunnel. CONCLUSION The novel compact wind tunnel developed here may be an alternative to field trials for testing FP efficacy, avoiding factors such as weather, logistical planning, and extended personnel hours. The wind tunnel could allow programs to conveniently test efficacy of multiple FP. Comparisons of different insecticide exposure methods provide practical information to inform operational decisions. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Stephanie L Richards
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
| | - Sinan Sousan
- Department of Public Health, Brody School of Medicine, East Carolina University, Greenville, NC, USA
- North Carolina Agromedicine Institute, East Carolina University, Greenville, NC, USA
| | - Will Murray
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
- Department of Public Health, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Avian White
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
| | - Kaya Peyton
- College of Health and Sciences, Department of Environmental, Earth, and Geospatial Science, North Carolina Central University, Durham, NC, USA
| | - Raven Slade
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
| |
Collapse
|
6
|
Giraldo D, McMeniman CJ. Quantifying Mosquito Host Preference. Cold Spring Harb Protoc 2024; 2024:107663. [PMID: 37612146 DOI: 10.1101/pdb.top107663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
The most dangerous mosquito species for human health are those that blood feed preferentially and frequently on humans (anthropophilic mosquitoes). These include prolific disease vectors such as the African malaria mosquito Anopheles gambiae and yellow fever mosquito Aedes aegypti The chemosensory basis for anthropophilic behavior exhibited by these disease vectors, as well as the factors that drive interindividual differences in human attractiveness to mosquitoes, remain largely uncharacterized. Here, we concisely review established methods to quantify mosquito interspecific and intraspecific host preference in the laboratory, as well as semi-field and field environments. Experimental variables for investigator consideration during assays of mosquito host preference across these settings are highlighted.
Collapse
Affiliation(s)
- Diego Giraldo
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Conor J McMeniman
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| |
Collapse
|
7
|
Costa-da-Silva AL, Cabal S, Lopez K, Boloix J, Rodriguez BG, Marrero KM, Bellantuono AJ, DeGennaro M. Female Aedes aegypti mosquitoes use communal cues to manage population density at breeding sites. Commun Biol 2024; 7:143. [PMID: 38297108 PMCID: PMC10830494 DOI: 10.1038/s42003-024-05830-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 01/18/2024] [Indexed: 02/02/2024] Open
Abstract
Where a female mosquito lays her eggs creates the conditions for reproductive success. Here we identify a communal behavior among ovipositing female mosquitoes. When choosing equal breeding sites, gravid Aedes aegypti aggregate more often than expected. This aggregation occurs when water contact is restricted and does not require the presence of eggs. Instead, the aggregation is regulated by the number of females present at the breeding site. Using assays with both occupied and empty oviposition sites, we show that the Orco olfactory co-receptor and a carbon dioxide receptor, Gr3, detect the presence of mosquitoes. orco mutants aggregate more often in empty sites, suggesting attractive olfactory cues influence females to associate with one another. Gr3 mutant females do not prefer either site, suggesting that the CO2 receptor is necessary to evaluate mosquito population density at breeding sites. Further, raising CO2 levels is sufficient to cause wild-type mosquitoes to avoid empty oviposition sites. Our results demonstrate that female mosquitoes can regulate their own population density at breeding sites using attractive and repellent communal cues.
Collapse
Affiliation(s)
- Andre Luis Costa-da-Silva
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Silvia Cabal
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Kristian Lopez
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Jean Boloix
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Brian Garcia Rodriguez
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Kaylee M Marrero
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Anthony J Bellantuono
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Matthew DeGennaro
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA.
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA.
| |
Collapse
|
8
|
Luker HA. A critical review of current laboratory methods used to evaluate mosquito repellents. FRONTIERS IN INSECT SCIENCE 2024; 4:1320138. [PMID: 38469342 PMCID: PMC10926509 DOI: 10.3389/finsc.2024.1320138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/02/2024] [Indexed: 03/13/2024]
Abstract
Pathogens transmitted by mosquitoes threaten human health around the globe. The use of effective mosquito repellents can protect individuals from contracting mosquito-borne diseases. Collecting evidence to confirm and quantify the effectiveness of a mosquito repellent is crucial and requires thorough standardized testing. There are multitudes of methods to test repellents that each have their own strengths and weaknesses. Determining which type of test to conduct can be challenging and the collection of currently used and standardized methods has changed over time. Some of these methods can be powerful to rapidly screen numerous putative repellent treatments. Other methods can test mosquito responses to specific treatments and measure either spatial or contact repellency. A subset of these methods uses live animals or human volunteers to test the repellency of treatments. Assays can greatly vary in their affordability and accessibility for researchers and/or may require additional methods to confirm results. Here I present a critical review that covers some of the most frequently used laboratory assays from the last two decades. I discuss the experimental designs and highlight some of the strengths and weaknesses of each type of method covered.
Collapse
Affiliation(s)
- Hailey A. Luker
- Molecular Vector Physiology Laboratory, Department of Biology, New Mexico State University, Las Cruces, NM, United States
| |
Collapse
|
9
|
Hinze A, Pelletier J, Ghaninia M, Marois E, Hill SR, Ignell R. Knockout of OR39 reveals redundancy in the olfactory pathway regulating the acquisition of host seeking in Anopheles coluzzii. Proc Biol Sci 2023; 290:20232092. [PMID: 38018099 PMCID: PMC10685123 DOI: 10.1098/rspb.2023.2092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/06/2023] [Indexed: 11/30/2023] Open
Abstract
The attraction of anthropophilic mosquitoes to human host cues, such as body odour and carbon dioxide, gradually increases during adult maturation. This acquisition of host-seeking behaviour correlates with age-dependent changes in odorant receptor (OR) transcript abundance and sensitivity of olfactory sensory neurons (OSNs). One OR gene of the human malaria vector, Anopheles coluzzii, AcolOR39, is significantly downregulated in mature females, and a cognate ligand of AcolOR39, sulcatone, a major component of human emanations, mediates the observed behavioural inhibition of newly emerged (teneral) females to human body odour. Knockout of AcolOR39, using CRISPR-Cas9 mutagenesis, selectively abolished sulcatone detection in OSNs, housed in trichoid sensilla. However, knockout of AcolOR39 altered neither the response rate nor the flight behaviour of teneral females in a wind tunnel, indicating the involvement of other genes, and thus a redundancy, in regulating the acquisition of host seeking in mosquitoes.
Collapse
Affiliation(s)
- Annika Hinze
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
| | - Julien Pelletier
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
| | - Majid Ghaninia
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Eric Marois
- Inserm, CNRS, Université de Strasbourg, Strasbourg 67070, France
| | - Sharon Rose Hill
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
| | - Rickard Ignell
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
| |
Collapse
|
10
|
Tao L, Wechsler SP, Bhandawat V. Sensorimotor transformation underlying odor-modulated locomotion in walking Drosophila. Nat Commun 2023; 14:6818. [PMID: 37884581 PMCID: PMC10603174 DOI: 10.1038/s41467-023-42613-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 10/17/2023] [Indexed: 10/28/2023] Open
Abstract
Most real-world behaviors - such as odor-guided locomotion - are performed with incomplete information. Activity in olfactory receptor neuron (ORN) classes provides information about odor identity but not the location of its source. In this study, we investigate the sensorimotor transformation that relates ORN activation to locomotion changes in Drosophila by optogenetically activating different combinations of ORN classes and measuring the resulting changes in locomotion. Three features describe this sensorimotor transformation: First, locomotion depends on both the instantaneous firing frequency (f) and its change (df); the two together serve as a short-term memory that allows the fly to adapt its motor program to sensory context automatically. Second, the mapping between (f, df) and locomotor parameters such as speed or curvature is distinct for each pattern of activated ORNs. Finally, the sensorimotor mapping changes with time after odor exposure, allowing information integration over a longer timescale.
Collapse
Affiliation(s)
- Liangyu Tao
- School of Biomedical Engineering and Health Sciences, Drexel University, Philadelphia, PA, USA
| | - Samuel P Wechsler
- School of Biomedical Engineering and Health Sciences, Drexel University, Philadelphia, PA, USA
- Department of Neurobiology and Anatomy, Drexel University, Philadelphia, PA, USA
| | - Vikas Bhandawat
- School of Biomedical Engineering and Health Sciences, Drexel University, Philadelphia, PA, USA.
| |
Collapse
|
11
|
Szyszka P, Emonet T, Edwards TL. Extracting spatial information from temporal odor patterns: insights from insects. CURRENT OPINION IN INSECT SCIENCE 2023; 59:101082. [PMID: 37419251 PMCID: PMC10878403 DOI: 10.1016/j.cois.2023.101082] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/09/2023]
Abstract
Extracting spatial information from temporal stimulus patterns is essential for sensory perception (e.g. visual motion direction detection or concurrent sound segregation), but this process remains understudied in olfaction. Animals rely on olfaction to locate resources and dangers. In open environments, where odors are dispersed by turbulent wind, detection of wind direction seems crucial for odor source localization. However, recent studies showed that insects can extract spatial information from the odor stimulus itself, independently from sensing wind direction. This remarkable ability is achieved by detecting the fine-scale temporal pattern of odor encounters, which contains information about the location and size of an odor source, and the distance between different odor sources.
Collapse
Affiliation(s)
- Paul Szyszka
- Department of Zoology, University of Otago, Dunedin, New Zealand.
| | - Thierry Emonet
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, USA
| | | |
Collapse
|
12
|
Steele TJ, Lanz AJ, Nagel KI. Olfactory navigation in arthropods. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:467-488. [PMID: 36658447 PMCID: PMC10354148 DOI: 10.1007/s00359-022-01611-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 12/26/2022] [Accepted: 12/31/2022] [Indexed: 01/21/2023]
Abstract
Using odors to find food and mates is one of the most ancient and highly conserved behaviors. Arthropods from flies to moths to crabs use broadly similar strategies to navigate toward odor sources-such as integrating flow information with odor information, comparing odor concentration across sensors, and integrating odor information over time. Because arthropods share many homologous brain structures-antennal lobes for processing olfactory information, mechanosensors for processing flow, mushroom bodies (or hemi-ellipsoid bodies) for associative learning, and central complexes for navigation, it is likely that these closely related behaviors are mediated by conserved neural circuits. However, differences in the types of odors they seek, the physics of odor dispersal, and the physics of locomotion in water, air, and on substrates mean that these circuits must have adapted to generate a wide diversity of odor-seeking behaviors. In this review, we discuss common strategies and specializations observed in olfactory navigation behavior across arthropods, and review our current knowledge about the neural circuits subserving this behavior. We propose that a comparative study of arthropod nervous systems may provide insight into how a set of basic circuit structures has diversified to generate behavior adapted to different environments.
Collapse
Affiliation(s)
- Theresa J Steele
- Neuroscience Institute, NYU School of Medicine, 435 E 30th St., New York, NY, 10016, USA
| | - Aaron J Lanz
- Neuroscience Institute, NYU School of Medicine, 435 E 30th St., New York, NY, 10016, USA
| | - Katherine I Nagel
- Neuroscience Institute, NYU School of Medicine, 435 E 30th St., New York, NY, 10016, USA.
| |
Collapse
|
13
|
Giraldo D, Rankin-Turner S, Corver A, Tauxe GM, Gao AL, Jackson DM, Simubali L, Book C, Stevenson JC, Thuma PE, McCoy RC, Gordus A, Mburu MM, Simulundu E, McMeniman CJ. Human scent guides mosquito thermotaxis and host selection under naturalistic conditions. Curr Biol 2023; 33:2367-2382.e7. [PMID: 37209680 PMCID: PMC10824255 DOI: 10.1016/j.cub.2023.04.050] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/23/2023] [Accepted: 04/21/2023] [Indexed: 05/22/2023]
Abstract
The African malaria mosquito Anopheles gambiae exhibits a strong innate drive to seek out humans in its sensory environment, classically entering homes to land on human skin in the hours flanking midnight. To gain insight into the role that olfactory cues emanating from the human body play in generating this epidemiologically important behavior, we developed a large-scale multi-choice preference assay in Zambia with infrared motion vision under semi-field conditions. We determined that An. gambiae prefers to land on arrayed visual targets warmed to human skin temperature during the nighttime when they are baited with carbon dioxide (CO2) emissions reflective of a large human over background air, body odor from one human over CO2, and the scent of one sleeping human over another. Applying integrative whole body volatilomics to multiple humans tested simultaneously in competition in a six-choice assay, we reveal high attractiveness is associated with whole body odor profiles from humans with increased relative abundances of the volatile carboxylic acids butyric acid, isobutryic acid, and isovaleric acid, and the skin microbe-generated methyl ketone acetoin. Conversely, those least preferred had whole body odor that was depleted of carboxylic acids among other compounds and enriched with the monoterpenoid eucalyptol. Across expansive spatial scales, heated targets without CO2 or whole body odor were minimally or not attractive at all to An. gambiae. These results indicate that human scent acts critically to guide thermotaxis and host selection by this prolific malaria vector as it navigates towards humans, yielding intrinsic heterogeneity in human biting risk.
Collapse
Affiliation(s)
- Diego Giraldo
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Stephanie Rankin-Turner
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Abel Corver
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Genevieve M Tauxe
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Anne L Gao
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Dorian M Jackson
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | | | - Christopher Book
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; Macha Research Trust, Choma District, PO Box 630166, Zambia
| | - Jennifer C Stevenson
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; Macha Research Trust, Choma District, PO Box 630166, Zambia
| | - Philip E Thuma
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; Macha Research Trust, Choma District, PO Box 630166, Zambia
| | - Rajiv C McCoy
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Andrew Gordus
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | | | - Conor J McMeniman
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
14
|
Heinonen RA, Biferale L, Celani A, Vergassola M. Optimal policies for Bayesian olfactory search in turbulent flows. Phys Rev E 2023; 107:055105. [PMID: 37329026 DOI: 10.1103/physreve.107.055105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 03/27/2023] [Indexed: 06/18/2023]
Abstract
In many practical scenarios, a flying insect must search for the source of an emitted cue which is advected by the atmospheric wind. On the macroscopic scales of interest, turbulence tends to mix the cue into patches of relatively high concentration over a background of very low concentration, so that the insect will detect the cue only intermittently and cannot rely on chemotactic strategies which simply climb the concentration gradient. In this work we cast this search problem in the language of a partially observable Markov decision process and use the Perseus algorithm to compute strategies that are near-optimal with respect to the arrival time. We test the computed strategies on a large two-dimensional grid, present the resulting trajectories and arrival time statistics, and compare these to the corresponding results for several heuristic strategies, including (space-aware) infotaxis, Thompson sampling, and QMDP. We find that the near-optimal policy found by our implementation of Perseus outperforms all heuristics we test by several measures. We use the near-optimal policy to study how the search difficulty depends on the starting location. We also discuss the choice of initial belief and the robustness of the policies to changes in the environment. Finally, we present a detailed and pedagogical discussion about the implementation of the Perseus algorithm, including the benefits-and pitfalls-of employing a reward-shaping function.
Collapse
Affiliation(s)
- R A Heinonen
- Department of Physics and INFN, University of Rome "Tor Vergata," Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - L Biferale
- Department of Physics and INFN, University of Rome "Tor Vergata," Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - A Celani
- Quantitative Life Sciences, Abdus Salam International Centre for Theoretical Physics, 34151 Trieste, Italy
| | - M Vergassola
- Laboratoire de Physique, École Normale Supérieure, CNRS, PSL Research University, Sorbonne University, 75005 Paris, France
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
| |
Collapse
|
15
|
Janson KD, Carter BH, Jameson SB, de Verges JE, Dalliance ES, Royse MK, Kim P, Wesson DM, Veiseh O. Development of an automated biomaterial platform to study mosquito feeding behavior. Front Bioeng Biotechnol 2023; 11:1103748. [PMID: 36845184 PMCID: PMC9946970 DOI: 10.3389/fbioe.2023.1103748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 01/12/2023] [Indexed: 02/11/2023] Open
Abstract
Mosquitoes carry a number of deadly pathogens that are transmitted while feeding on blood through the skin, and studying mosquito feeding behavior could elucidate countermeasures to mitigate biting. Although this type of research has existed for decades, there has yet to be a compelling example of a controlled environment to test the impact of multiple variables on mosquito feeding behavior. In this study, we leveraged uniformly bioprinted vascularized skin mimics to create a mosquito feeding platform with independently tunable feeding sites. Our platform allows us to observe mosquito feeding behavior and collect video data for 30-45 min. We maximized throughput by developing a highly accurate computer vision model (mean average precision: 92.5%) that automatically processes videos and increases measurement objectivity. This model enables assessment of critical factors such as feeding and activity around feeding sites, and we used it to evaluate the repellent effect of DEET and oil of lemon eucalyptus-based repellents. We validated that both repellents effectively repel mosquitoes in laboratory settings (0% feeding in experimental groups, 13.8% feeding in control group, p < 0.0001), suggesting our platform's use as a repellent screening assay in the future. The platform is scalable, compact, and reduces dependence on vertebrate hosts in mosquito research.
Collapse
Affiliation(s)
- Kevin D. Janson
- Department of Bioengineering, Rice University, Houston, TX, United States
| | - Brendan H. Carter
- Department of Tropical Medicine, Tulane University, New Orleans, LA, United States
| | - Samuel B. Jameson
- Department of Tropical Medicine, Tulane University, New Orleans, LA, United States
| | - Jane E. de Verges
- Department of Tropical Medicine, Tulane University, New Orleans, LA, United States
| | - Erika S. Dalliance
- Department of Tropical Medicine, Tulane University, New Orleans, LA, United States
| | - Madison K. Royse
- Department of Bioengineering, Rice University, Houston, TX, United States
| | - Paul Kim
- Department of Bioengineering, Rice University, Houston, TX, United States
| | - Dawn M. Wesson
- Department of Tropical Medicine, Tulane University, New Orleans, LA, United States,*Correspondence: Omid Veiseh, ; Dawn M. Wesson,
| | - Omid Veiseh
- Department of Bioengineering, Rice University, Houston, TX, United States,*Correspondence: Omid Veiseh, ; Dawn M. Wesson,
| |
Collapse
|
16
|
Wechsler SP, Bhandawat V. Behavioral algorithms and neural mechanisms underlying odor-modulated locomotion in insects. J Exp Biol 2023; 226:jeb200261. [PMID: 36637433 PMCID: PMC10086387 DOI: 10.1242/jeb.200261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Odors released from mates and resources such as a host and food are often the first sensory signals that an animal can detect. Changes in locomotion in response to odors are an important mechanism by which animals access resources important to their survival. Odor-modulated changes in locomotion in insects constitute a whole suite of flexible behaviors that allow insects to close in on these resources from long distances and perform local searches to locate and subsequently assess them. Here, we review changes in odor-mediated locomotion across many insect species. We emphasize that changes in locomotion induced by odors are diverse. In particular, the olfactory stimulus is sporadic at long distances and becomes more continuous at short distances. This distance-dependent change in temporal profile produces a corresponding change in an insect's locomotory strategy. We also discuss the neural circuits underlying odor modulation of locomotion.
Collapse
Affiliation(s)
- Samuel P. Wechsler
- School of Biomedical Engineering, Sciences and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Vikas Bhandawat
- School of Biomedical Engineering, Sciences and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| |
Collapse
|
17
|
Sumner BD, Cardé RT. Primacy of Human Odors Over Visual and Heat Cues in Inducing Landing in Female Aedes aegypti Mosquitoes. JOURNAL OF INSECT BEHAVIOR 2022; 35:31-43. [PMID: 35846381 PMCID: PMC9276619 DOI: 10.1007/s10905-022-09796-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Although human skin odor is thought to be the cue that anthropophilic mosquitoes use to discriminate us from other potential hosts, the precise details of how they use skin odor to find and land on a human is unclear. We found that Aedes aegypti land on a source of skin odor without a co-located visual cue. By collecting human odor on glass beads and using identical glass beads to visually conceal skin odor and heat cues, we were able to study mosquito landing on skin odor, heat, and visual cues separately. Landing is necessary for blood feeding which is a required behavior for the Aedes aegypti life cycle as well as the behavior responsible for the epidemiological impact of mosquitoes. Therefore, we consider it to be the diagnostic measure of the importance of a host cue. In two-choice tests, a skin odor source had the highest valence for landing, followed by a combination of heat and a visual cue, and finally heat and visual cues presented separately. We also measured the durations of the landings, though no significant differences were found. Supplementary Information The online version contains supplementary material available at 10.1007/s10905-022-09796-2.
Collapse
Affiliation(s)
- Benjamin D. Sumner
- Department of Entomology, University of California, Riverside, CA 92521 USA
| | - Ring T. Cardé
- Department of Entomology, University of California, Riverside, CA 92521 USA
| |
Collapse
|
18
|
Sorrells TR, Pandey A, Rosas-Villegas A, Vosshall LB. A persistent behavioral state enables sustained predation of humans by mosquitoes. eLife 2022; 11:76663. [PMID: 35550041 PMCID: PMC9154740 DOI: 10.7554/elife.76663] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
Predatory animals pursue prey in a noisy sensory landscape, deciding when to continue or abandon their chase. The mosquito Aedes aegypti is a micropredator that first detects humans at a distance through sensory cues such as carbon dioxide. As a mosquito nears its target, it senses more proximal cues such as body heat that guide it to a meal of blood. How long the search for blood continues after initial detection of a human is not known. Here, we show that a 5 s optogenetic pulse of fictive carbon dioxide induced a persistent behavioral state in female mosquitoes that lasted for more than 10 min. This state is highly specific to females searching for a blood meal and was not induced in recently blood-fed females or in males, who do not feed on blood. In males that lack the gene fruitless, which controls persistent social behaviors in other insects, fictive carbon dioxide induced a long-lasting behavior response resembling the predatory state of females. Finally, we show that the persistent state triggered by detection of fictive carbon dioxide enabled females to engorge on a blood meal mimic offered up to 14 min after the initial 5 s stimulus. Our results demonstrate that a persistent internal state allows female mosquitoes to integrate multiple human sensory cues over long timescales, an ability that is key to their success as an apex micropredator of humans.
Collapse
Affiliation(s)
- Trevor R Sorrells
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, San Francisco, United States
| | - Anjali Pandey
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, United States
| | - Adriana Rosas-Villegas
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, United States
| | - Leslie B Vosshall
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, United States
| |
Collapse
|
19
|
Zhao Z, Zung JL, Hinze A, Kriete AL, Iqbal A, Younger MA, Matthews BJ, Merhof D, Thiberge S, Ignell R, Strauch M, McBride CS. Mosquito brains encode unique features of human odour to drive host seeking. Nature 2022; 605:706-712. [PMID: 35508661 DOI: 10.1038/s41586-022-04675-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 03/22/2022] [Indexed: 11/09/2022]
Abstract
A globally invasive form of the mosquito Aedes aegypti specializes in biting humans, making it an efficient disease vector1. Host-seeking female mosquitoes strongly prefer human odour over the odour of animals2,3, but exactly how they distinguish between the two is not known. Vertebrate odours are complex blends of volatile chemicals with many shared components4-7, making discrimination an interesting sensory coding challenge. Here we show that human and animal odours evoke activity in distinct combinations of olfactory glomeruli within the Ae. aegypti antennal lobe. One glomerulus in particular is strongly activated by human odour but responds weakly, or not at all, to animal odour. This human-sensitive glomerulus is selectively tuned to the long-chain aldehydes decanal and undecanal, which we show are consistently enriched in human odour and which probably originate from unique human skin lipids. Using synthetic blends, we further demonstrate that signalling in the human-sensitive glomerulus significantly enhances long-range host-seeking behaviour in a wind tunnel, recapitulating preference for human over animal odours. Our research suggests that animal brains may distil complex odour stimuli of innate biological relevance into simple neural codes and reveals targets for the design of next-generation mosquito-control strategies.
Collapse
Affiliation(s)
- Zhilei Zhao
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA. .,Bezos Center for Neural Circuit Dynamics, Princeton University, Princeton, NJ, USA. .,Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, USA. .,Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA.
| | - Jessica L Zung
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.,Bezos Center for Neural Circuit Dynamics, Princeton University, Princeton, NJ, USA.,Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Annika Hinze
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Alexis L Kriete
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.,Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, USA.,Graduate Program in Entomology, North Carolina State University, Raleigh, NC, USA
| | - Azwad Iqbal
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.,Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, USA.,Department of Natural Resources and the Environment, Cornell University, Ithaca, NY, USA
| | - Meg A Younger
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY, USA.,Department of Biology, Boston University, Boston, MA, USA
| | - Benjamin J Matthews
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY, USA.,Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dorit Merhof
- Institute of Imaging & Computer Vision, RWTH Aachen University, Aachen, Germany
| | - Stephan Thiberge
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.,Bezos Center for Neural Circuit Dynamics, Princeton University, Princeton, NJ, USA
| | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Martin Strauch
- Institute of Imaging & Computer Vision, RWTH Aachen University, Aachen, Germany
| | - Carolyn S McBride
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA. .,Bezos Center for Neural Circuit Dynamics, Princeton University, Princeton, NJ, USA. .,Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, USA.
| |
Collapse
|
20
|
Diurnal and nocturnal mosquitoes escape looming threats using distinct flight strategies. Curr Biol 2022; 32:1232-1246.e5. [DOI: 10.1016/j.cub.2022.01.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/21/2021] [Accepted: 01/12/2022] [Indexed: 11/21/2022]
|
21
|
Tenywa FSC, Musa JJ, Musiba RM, Swai JK, Mpelepele AB, Okumu FO, Maia MF. Evaluation of an ivermectin-based attractive targeted sugar bait (ATSB) against Aedes aegypti in Tanzania. Wellcome Open Res 2022; 7:4. [PMID: 37409221 PMCID: PMC10318376 DOI: 10.12688/wellcomeopenres.17442.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2021] [Indexed: 10/02/2023] Open
Abstract
Background The control of vector borne arboviral diseases such as Dengue is mainly achieved by reducing human-vector contact and controlling the vectors through source reduction and environmental management. These measures are constrained by labour intensity, insecticide resistance and pro-active community participation. The current study intended to develop and test an ivermectin-based attractive-targeted sugar bait (ATSB) against Aedes aegypti. Methods The 48hour lethal concentration (LC90) of ivermectin against Ae. aegypti was determined through serial dilution experiment where five 30cm x 30cm x 30cm cages were set; into each, a 10% sugar solution treated with ivermectin were introduced. 40 Ae. aegypti were released into each cage and observed for mortality after 4, 8, 24 and 48 hours. The ivermectin-based ATSB was evaluated in a semi field system where ATSB and attractive sugar bait (ASB) were deployed into each compartment of the semi field and 100 female Ae. aegypti were released every day and recaptured the next day through human land catch and Bio-gent sentinel trap. The developed and semi-field tested ATSB was further tested in the field by deploying them in garages. Results The ivermectin 48hr LC90 of male and female Ae. aegypti was found to be 0.03% w/v. In the semi field system, the ATSB significantly reduced a free-flying population of Ae. aegypti within 24 hours (incidence rate ratio (IRR) = 0.62; [95% confidence interval (95%CI); 0.54-0.70] and p-value < 0.001). However, in the field, the ATSBs required the addition of yeast as a carbon dioxide source to efficiently attract Ae. aegypti mosquitoes to feed. Conclusion Ivermectin is an active ingredient that can be used in an ATSB for Ae. aegypti depopulation. However, further research is needed to improve the developed and tested ATSB to compete with natural sources of sugar in a natural environment.
Collapse
Affiliation(s)
- Frank Sandra Chelestino Tenywa
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Bagamoyo, Pwani, 0000, Tanzania
- Vector Biology, Swiss Tropical and Public Health Institute, Basel, Basel, CH-4002, Switzerland
- Science, University of Basel, Basel, Basel, CH-4002, Switzerland
| | - Jeremiah John Musa
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Bagamoyo, Pwani, 0000, Tanzania
| | - Revocatus Musyangi Musiba
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Bagamoyo, Pwani, 0000, Tanzania
| | - Johnson Kyeba Swai
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Bagamoyo, Pwani, 0000, Tanzania
- Vector Biology, Swiss Tropical and Public Health Institute, Basel, Basel, CH-4002, Switzerland
- Science, University of Basel, Basel, Basel, CH-4002, Switzerland
| | - Ahmad Bakar Mpelepele
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Bagamoyo, Pwani, 0000, Tanzania
| | - Fredros Okech Okumu
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Bagamoyo, Pwani, 0000, Tanzania
- Vector Biology, Swiss Tropical and Public Health Institute, Basel, Basel, CH-4002, Switzerland
- Science, University of Basel, Basel, Basel, CH-4002, Switzerland
- Faculty of Health Science, School of Public Health, University of the Witwatersrand, Johannesburg, Johannesburg, 0000, South Africa
| | - Marta Ferreira Maia
- Wellcome Trust Research Program, Kenya Medical Research Institute(Kemri ), Kilifi, Mombasa, 0000, Kenya
- Medicine, Centre for Global Health and Tropical Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| |
Collapse
|
22
|
Crawley SE, Borden JH. Detection and monitoring of bed bugs (Hemiptera: Cimicidae): review of the underlying science, existing products and future prospects. PEST MANAGEMENT SCIENCE 2021; 77:5334-5346. [PMID: 34312971 DOI: 10.1002/ps.6574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/19/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Bed bugs, Cimex lectularius L. and C. hemipterus (F.) (Hemiptera: Cimicidae) are hematophagous ectoparasites of humans. Since the resurgence of bed bugs in the late 1990s there has been a corresponding emphasis on development and implementation of integrated pest management (IPM) programs to manage infestations. One critical requirement of IPM is the ability to detect and monitor the target pest. We outline and describe the majority of all known existing devices and technologies developed for bed bug detection and monitoring as well as much of the underlying science. Almost 40 detection and monitoring products have flooded the marketplace, but for various reasons, including price, size, complexity and lack of independent scientific evaluation, they have not been widely adopted for IPM in structures. One product, the ClimbUp® Insect Interceptor, has nine competitors that utilize a similar design. This review also discloses many other technologies and products that are either too expensive or too impractical for use as either consumer or industrial products. We conclude that there is a critical need for inexpensive and effective detection and monitoring traps and lures suitable for widespread adoption by the urban pest control industry. © 2021 Society of Chemical Industry.
Collapse
Affiliation(s)
- Sydney E Crawley
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, USA
| | | |
Collapse
|
23
|
Elimination of vision-guided target attraction in Aedes aegypti using CRISPR. Curr Biol 2021; 31:4180-4187.e6. [PMID: 34331858 PMCID: PMC8478898 DOI: 10.1016/j.cub.2021.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 05/19/2021] [Accepted: 07/02/2021] [Indexed: 01/11/2023]
Abstract
Blood-feeding insects, such as the mosquito, Aedes (Ae.) aegypti, use multiple senses to seek out and bite humans.1,2 Upon exposure to the odor of CO2, the attention of female mosquitoes to potential targets is greatly increased. Female mosquitoes are attracted to high-contrast visual cues and use skin olfactory cues to assist them in homing in on targets several meters away.3-9 Within close range, convective heat from skin and additional skin odors further assist the mosquitoes' evaluation as to whether the object of interest might be a host.10,11 Here, using CRISPR-Cas9, we mutated the gene encoding Op1, which is the most abundant of the five rhodopsins expressed in the eyes of Ae. aegypti. Using cage and wind-tunnel assays, we found that elimination of op1 did not impair CO2-induced target seeking. We then mutated op2, which encodes the rhodopsin most similar to Op1, and also found that there was no impact on this behavior. Rather, mutation of both op1 and op2 was required for abolishing vision-guided target attraction. In contrast, the double mutants exhibited normal phototaxis and odor-tracking responses. By measuring the walking optomotor response, we found that the double mutants still perceived optic flow. In further support of the conclusion that the double mutant is not blind, the animals retained an electrophysiological response to light, although it was diminished. This represents the first genetic perturbation of vision in mosquitoes and indicates that vision-guided target attraction by Ae. aegypti depends on two highly related rhodopsins.
Collapse
|
24
|
Mongeau JM, Schweikert LE, Davis AL, Reichert MS, Kanwal JK. Multimodal integration across spatiotemporal scales to guide invertebrate locomotion. Integr Comp Biol 2021; 61:842-853. [PMID: 34009312 DOI: 10.1093/icb/icab041] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Locomotion is a hallmark of organisms that has enabled adaptive radiation to an extraordinarily diverse class of ecological niches, and allows animals to move across vast distances. Sampling from multiple sensory modalities enables animals to acquire rich information to guide locomotion. Locomotion without sensory feedback is haphazard, therefore sensory and motor systems have evolved complex interactions to generate adaptive behavior. Notably, sensory-guided locomotion acts over broad spatial and temporal scales to permit goal-seeking behavior, whether to localize food by tracking an attractive odor plume or to search for a potential mate. How does the brain integrate multimodal stimuli over different temporal and spatial scales to effectively control behavior? In this review, we classify locomotion into three ordinally ranked hierarchical layers that act over distinct spatiotemporal scales: stabilization, motor primitives, and higher-order tasks, respectively. We discuss how these layers present unique challenges and opportunities for sensorimotor integration. We focus on recent advances in invertebrate locomotion due to their accessible neural and mechanical signals from the whole brain, limbs and sensors. Throughout, we emphasize neural-level description of computations for multimodal integration in genetic model systems, including the fruit fly, Drosophila melanogaster, and the yellow fever mosquito, Aedes aegypti. We identify that summation (e.g. gating) and weighting-which are inherent computations of spiking neurons-underlie multimodal integration across spatial and temporal scales, therefore suggesting collective strategies to guide locomotion.
Collapse
Affiliation(s)
- Jean-Michel Mongeau
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Lorian E Schweikert
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, FL 33181. University of North Carolina Wilmington, Department of Biology and Marine Biology, Wilmington, NC, U.S.A
| | | | - Michael S Reichert
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jessleen K Kanwal
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| |
Collapse
|
25
|
Üçpunar HK, Grunwald Kadow IC. Flies Avoid Current Atmospheric CO 2 Concentrations. Front Physiol 2021; 12:646401. [PMID: 33927640 PMCID: PMC8076854 DOI: 10.3389/fphys.2021.646401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/22/2021] [Indexed: 11/23/2022] Open
Abstract
CO2 differs from most other odors by being ubiquitously present in the air animals inhale. CO2 levels of the atmosphere, however, are subject to change. Depending on the landscape, temperature, and time of the year, CO2 levels can change even on shortest time scales. In addition, since the 18th century the CO2 baseline keeps increasing due to the intensive fossil fuel usage. However, we do not know whether this change is significant for animals, and if yes whether and how animals adapt to this change. Most insects possess olfactory receptors to detect the gaseous molecule, and CO2 is one of the key odorants for insects such as the vinegar fly Drosophila melanogaster to find food sources and to warn con-specifics. So far, CO2 and its sensory system have been studied in the context of rotting fruit and other CO2-emitting sources to investigate flies’ response to significantly elevated levels of CO2. However, it has not been addressed whether flies detect and potentially react to atmospheric levels of CO2. By using behavioral experiments, here we show that flies can detect atmospheric CO2 concentrations and, if given the choice, prefer air with sub-atmospheric levels of the molecule. Blocking the synaptic release from CO2 receptor neurons abolishes this choice. Based on electrophysiological recordings, we hypothesize that CO2 receptors, similar to ambient temperature receptors, actively sample environmental CO2 concentrations close to atmospheric levels. Based on recent findings and our data, we hypothesize that Gr-dependent CO2 receptors do not primarily serve as a cue detector to find food sources or avoid danger, instead they function as sensors for preferred environmental conditions.
Collapse
Affiliation(s)
- Habibe K Üçpunar
- Department of Physiology, School of Medicine, Ankara Medipol University, Ankara, Turkey
| | | |
Collapse
|
26
|
Mayton EH, Hernandez HM, Vitek CJ, Christofferson RC. A Method for Repeated, Longitudinal Sampling of Individual Aedes aegypti for Transmission Potential of Arboviruses. INSECTS 2021; 12:292. [PMID: 33801709 PMCID: PMC8065608 DOI: 10.3390/insects12040292] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 11/21/2022]
Abstract
Mosquito-borne viruses are the cause of significant morbidity and mortality worldwide, especially in low- and middle-income countries. Assessing risk for viral transmission often involves characterization of the vector competence of vector-virus pairings. The most common determination of vector competence uses discreet, terminal time points, which cannot be used to investigate variation in transmission aspects, such as biting behavior, over time. Here, we present a novel method to longitudinally measure individual biting behavior and Zika virus (ZIKV) transmission. Individual mosquitoes were exposed to ZIKV, and from 9 to 24 days post-exposure, individuals were each offered a 180 μL bloodmeal every other day. Biting behavior was observed and characterized as either active probing, feeding, or no bite. The bloodmeal was then collected, spun down, serum collected, and tested for ZIKV RNA via qRT-PCR to determine individuals' vector competence over time. This included whether transmission to the bloodmeal was successful and the titer of expectorated virus. Additionally, serum was inoculated onto Vero cells in order to determine infectiousness of positive recovered sera. Results demonstrate heterogeneity in not only biting patterns but expectorated viral titers among individual mosquitoes over time. These findings demonstrate that the act of transmission is a complex process governed by mosquito behavior and mosquito-virus interaction, and herein we offer a method to investigate this phenomenon.
Collapse
Affiliation(s)
- E. Handly Mayton
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA;
| | - Heather M. Hernandez
- Center for Vector-Borne Diseases, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA; (H.M.H.); (C.J.V.)
| | - Christopher J. Vitek
- Center for Vector-Borne Diseases, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA; (H.M.H.); (C.J.V.)
| | - Rebecca C. Christofferson
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA;
- Center for Computation and Technology, Louisiana State University, Baton Rouge, LA 70803, USA
| |
Collapse
|
27
|
Differential Gene Expression in the Heads of Behaviorally Divergent Culex pipiens Mosquitoes. INSECTS 2021; 12:insects12030271. [PMID: 33806861 PMCID: PMC8005152 DOI: 10.3390/insects12030271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/15/2021] [Indexed: 11/17/2022]
Abstract
Host preferences of Cx. pipiens, a bridge vector for West Nile virus to humans, have the potential to drive pathogen transmission dynamics. Yet much remains unknown about the extent of variation in these preferences and their molecular basis. We conducted host choice assays in a laboratory setting to quantify multi-day human and avian landing rates for Cx. pipiens females. Assayed populations originated from five above-ground and three below-ground breeding and overwintering habitats. All three below-ground populations were biased toward human landings, with rates of human landing ranging from 69-85%. Of the five above-ground populations, four had avian landing rates of >80%, while one landed on the avian host only 44% of the time. Overall response rates and willingness to alternate landing on the human and avian hosts across multiple days of testing also varied by population. For one human- and one avian-preferring population, we examined patterns of differential expression and splice site variation at genes expressed in female heads. We also compared gene expression and splice site variation within human-seeking females in either gravid or host-seeking physiological states to identify genes that may regulate blood feeding behaviors. Overall, we identified genes with metabolic and regulatory function that were differentially expressed in our comparison of gravid and host-seeking females. Differentially expressed genes in our comparison of avian- and human-seeking females were enriched for those involved in sensory perception. We conclude with a discussion of specific sensory genes and their potential influence on the divergent behaviors of avian- and human-seeking Cx. pipiens.
Collapse
|
28
|
Dormont L, Mulatier M, Carrasco D, Cohuet A. Mosquito Attractants. J Chem Ecol 2021; 47:351-393. [PMID: 33725235 DOI: 10.1007/s10886-021-01261-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/18/2021] [Accepted: 03/02/2021] [Indexed: 01/01/2023]
Abstract
Vector control and personal protection against anthropophilic mosquitoes mainly rely on the use of insecticides and repellents. The search for mosquito-attractive semiochemicals has been the subject of intense studies for decades, and new compounds or odor blends are regularly proposed as lures for odor-baited traps. We present a comprehensive and up-to-date review of all the studies that have evaluated the attractiveness of volatiles to mosquitoes, including individual chemical compounds, synthetic blends of compounds, or natural host or plant odors. A total of 388 studies were analysed, and our survey highlights the existence of 105 attractants (77 volatile compounds, 17 organism odors, and 11 synthetic blends) that have been proved effective in attracting one or several mosquito species. The exhaustive list of these attractants is presented in various tables, while the most common mosquito attractants - for which effective attractiveness has been demonstrated in numerous studies - are discussed throughout the text. The increasing knowledge on compounds attractive to mosquitoes may now serve as the basis for complementary vector control strategies, such as those involving lure-and-kill traps, or the development of mass trapping. This review also points out the necessity of further improving the search for new volatile attractants, such as new compound blends in specific ratios, considering that mosquito attraction to odors may vary over the life of the mosquito or among species. Finally, the use of mosquito attractants will undoubtedly have an increasingly important role to play in future integrated vector management programs.
Collapse
Affiliation(s)
- Laurent Dormont
- CEFE, Univ Paul Valéry Montpellier 3, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France.
| | - Margaux Mulatier
- Institut Pasteur de Guadeloupe, Laboratoire d'étude sur le contrôle des vecteurs (LeCOV), Lieu-Dit Morne Jolivièrex, 97139, Les Abymes, Guadeloupe, France
| | - David Carrasco
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France
| | - Anna Cohuet
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France
| |
Collapse
|
29
|
Hinze A, Lantz J, Hill SR, Ignell R. Mosquito Host Seeking in 3D Using a Versatile Climate-Controlled Wind Tunnel System. Front Behav Neurosci 2021; 15:643693. [PMID: 33776664 PMCID: PMC7991727 DOI: 10.3389/fnbeh.2021.643693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/15/2021] [Indexed: 12/25/2022] Open
Abstract
Future anthropogenic climate change is predicted to impact sensory-driven behaviors. Building on recent improvements in computational power and tracking technology, we have developed a versatile climate-controlled wind tunnel system, in which to study the effect of climate parameters, including temperature, precipitation, and elevated greenhouse gas levels, on odor-mediated behaviors in insects. To establish a baseline for future studies, we here analyzed the host-seeking behavior of the major malaria vector mosquito, Anopheles gambiae sensu strico, to human odor and carbon dioxide (CO2), under tightly controlled climatic conditions, and isolated from potential background contamination by the presence of an experimenter. When presented with a combination of human foot odor and CO2 (case study I), mosquitoes engaged in faster crosswind flight, spent more time in the filamentous odor plume and targeted the odor source more successfully. In contrast, female An. gambiae s. s. presented with different concentrations of CO2 alone, did not display host-seeking behavior (case study II). These observations support previous findings on the role of human host-associated cues in host seeking and confirm the role of CO2 as a synergist, but not a host-seeking cue on its own. Future studies are aimed at investigating the effect of climate change on odor-mediated behavior in mosquitoes and other insects. Moreover, the system will be used to investigate detection and processing of olfactory information in various behavioral contexts, by providing a fine-scale analysis of flight behavior.
Collapse
Affiliation(s)
- Annika Hinze
- Disease Vector Group, Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Jörgen Lantz
- Jörgen Lantz Engineering Consulting Firm, Alnarp, Sweden
| | - Sharon R Hill
- Disease Vector Group, Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.,Max Planck Centre Next Generation Chemical Ecology, Uppsala, Sweden
| | - Rickard Ignell
- Disease Vector Group, Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.,Max Planck Centre Next Generation Chemical Ecology, Uppsala, Sweden
| |
Collapse
|
30
|
Cardé RT. Navigation Along Windborne Plumes of Pheromone and Resource-Linked Odors. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:317-336. [PMID: 32926790 DOI: 10.1146/annurev-ento-011019-024932] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Many insects locate resources such as a mate, a host, or food by flying upwind along the odor plumes that these resources emit to their source. A windborne plume has a turbulent structure comprised of odor filaments interspersed with clean air. As it propagates downwind, the plume becomes more dispersed and dilute, but filaments with concentrations above the threshold required to elicit a behavioral response from receiving organisms can persist for long distances. Flying insects orient along plumes by steering upwind, triggered by the optomotor reaction. Sequential measurements of differences in odor concentration are unreliable indicators of distance to or direction of the odor source. Plume intermittency and the plume's fine-scale structure can play a role in setting an insect's upwind course. The prowess of insects in navigating to odor sources has spawned bioinspired virtual models and even odor-seeking robots, although some of these approaches use mechanisms that are unnecessarily complex and probably exceed an insect's processing capabilities.
Collapse
Affiliation(s)
- Ring T Cardé
- Department of Entomology, University of California, Riverside, California 92521, USA;
| |
Collapse
|
31
|
Jones J, Murray GPD, McCall PJ. A minimal 3D model of mosquito flight behaviour around the human baited bed net. Malar J 2021; 20:24. [PMID: 33413370 PMCID: PMC7792054 DOI: 10.1186/s12936-020-03546-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/12/2020] [Indexed: 02/08/2023] Open
Abstract
Background Advances in digitized video-tracking and behavioural analysis have enabled accurate recording and quantification of mosquito flight and host-seeking behaviours, facilitating development of individual (agent) based models at much finer spatial scales than previously possible. Methods Quantified behavioural parameters were used to create a novel virtual testing model, capable of accurately simulating indoor flight behaviour by a virtual population of host-seeking mosquitoes as they interact with and respond to simulated stimuli from a human-occupied bed net. The model is described, including base mosquito behaviour, state transitions, environmental representation and host stimulus representation. Results In the absence of a bed net and human host bait, flight distribution of the model population was relatively uniform throughout the arena. Introducing an unbaited untreated bed net induced a change in distribution with an increase in landing events on the net surface, predominantly on the sides of the net. Adding the presence of a simulated human bait dramatically impacted flight distribution patterns, exploratory foraging and, the number and distribution of landing positions on the net, which were determined largely by the orientation of the human within. The model replicates experimental results with free-flying living mosquitoes at human-occupied bed nets, where contact occurs predominantly on the top surface of the net. This accuracy is important as it quantifies exposure to the lethal insecticide residues that may be unique to the net roof (or theoretically any other surface). Number of net contacts and height of contacts decreased with increasing attractant dispersal noise. Conclusions Results generated by the model are an accurate representation of actual mosquito behaviour recorded at and around a human-occupied bed net in untreated and insecticide-treated nets. This fine-grained model is highly flexible and has significant potential for in silico screening of novel bed net designs, potentially reducing time and cost and accelerating the deployment of new and more effective tools for protecting against malaria in sub-Saharan Africa.
Collapse
Affiliation(s)
- Jeff Jones
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
| | - Gregory P D Murray
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
| | - Philip J McCall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK.
| |
Collapse
|
32
|
Ando N, Kanzaki R. Insect-machine hybrid robot. CURRENT OPINION IN INSECT SCIENCE 2020; 42:61-69. [PMID: 32992040 DOI: 10.1016/j.cois.2020.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/12/2020] [Accepted: 09/16/2020] [Indexed: 06/11/2023]
Abstract
Recently, insect-machine hybrid robots have been developed that incorporate insects into robots or incorporate machines into insects. Most previous studies were motivated to use the function of insects for robots, but this technology can also prove to be useful as an experimental tool for neuroethology. We reviewed hybrid robots in terms of the closed-loop between an insect, a robot, and the real environment. The incorporated biological components provided the robot sensory signals that were received by the insects and the adaptive functions of the brain. The incorporated artificial components permitted us to understand the biological system by controlling insect behavior. Hybrid robots thus extend the roles of mobile robot experiments in neuroethology for both model evaluation and brain function analysis.
Collapse
Affiliation(s)
- Noriyasu Ando
- Department of Systems Life Engineering, Maebashi Institute of Technology, 460-1, Kamisadori-cho, Maebashi, Gunma 371-0816, Japan.
| | - Ryohei Kanzaki
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| |
Collapse
|
33
|
Huff RM, Pitts RJ. Carboxylic acid responses by a conserved odorant receptor in culicine vector mosquitoes. INSECT MOLECULAR BIOLOGY 2020; 29:523-530. [PMID: 32715523 DOI: 10.1111/imb.12661] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/26/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Many mosquito behaviours that are critical for survival and reproduction depend upon timely responses to chemical cues. Of interest are the effects of volatile organic compounds like carboxylic acids (CAs) that are released by potential blood meal hosts. Short chain CAs are among the primary attractants for host-seeking females and influence host selection in vector species. Although the behavioural relevance of CA's has been established, less is known about the molecular receptive events that evoke responses to specific compounds, with the Ir family of chemoreceptors being broadly implicated in their detection. In this study, we demonstrate that Or orthologs from two vector species, Aedes aegypti (L.) and Aedes albopictus (Skuse), are selectively activated by straight chain carboxylic acids and that these responses are attenuated by the commercial insect repellant N,N-Diethyl-meta-toluamide. Our results suggest that multiple chemoreceptors, representing diverse families, are able to mediate molecular responses to CAs and may therefore underlie important behaviours that directly impact disease-transmission cycles.
Collapse
Affiliation(s)
- Robert M Huff
- Department of Biology, Baylor University, Waco, TX, USA
| | - R Jason Pitts
- Department of Biology, Baylor University, Waco, TX, USA
| |
Collapse
|
34
|
Cribellier A, Spitzen J, Fairbairn H, van de Geer C, van Leeuwen JL, Muijres FT. Lure, retain, and catch malaria mosquitoes. How heat and humidity improve odour-baited trap performance. Malar J 2020; 19:357. [PMID: 33028362 PMCID: PMC7542916 DOI: 10.1186/s12936-020-03403-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/31/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND When seeking a human for a blood meal, mosquitoes use several cues to detect and find their hosts. From this knowledge, counter-flow odour-baited traps have been developed that use a combination of CO2, human-mimicking odour, visual cues and circulating airflow to attract and capture mosquitoes. Initially developed for monitoring, these traps are now also being considered as promising vector control tools. The traps are attractive to host-seeking mosquitoes, but their capture efficiency is low. It has been hypothesized that the lack of short-range host cues, such as heat and increased local humidity, often prevent mosquitoes from getting close enough to get caught; this lack might even trigger avoidance manoeuvres near the capture region. METHODS This study investigated how close-range host cues affect the flight behaviour of Anopheles female malaria mosquitoes around odour-baited traps, and how this affects trap capture performance. For this, a novel counter-flow odour-baited trap was developed, the M-Tego. In addition to the usual CO2 and odour-blend, this trap can provide the short-range host cues, heat and humidity. Systematically adding or removing these two cues tested how this affected the trap capture percentages and flight behaviour. First, capture percentages of the M-Tego with and without short-range host cues to the BG-Suna trap were compared, in both laboratory and semi-field testing. Then, machine-vision techniques were used to track the three-dimensional flight movements of mosquitoes around the M-Tego. RESULTS With heat and humidity present, the M-Tego captured significantly more mosquitoes as capture percentages almost doubled. Comparing the flight behaviour around the M-Tego with variable close-range host cues showed that when these cues were present, flying mosquitoes were more attracted to the trap and spent more time there. In addition, the M-Tego was found to have a better capture mechanism than the BG-Suna, most likely because it does not elicit previously observed upward avoiding manoeuvres. CONCLUSIONS Results suggest that adding heat and humidity to an odour-baited trap lures more mosquitoes close to the trap and retains them there longer, resulting in higher capture performance. These findings support the development of control tools for fighting mosquito-borne diseases such as malaria.
Collapse
Affiliation(s)
- Antoine Cribellier
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Jeroen Spitzen
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands
| | - Henry Fairbairn
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands.,Faculty of Industrial Design Engineering, Delft University of Technology, Delft, The Netherlands
| | - Cedric van de Geer
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands.,Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands.,Faculty of Industrial Design Engineering, Delft University of Technology, Delft, The Netherlands.,Ifakara Health Institute, Ifakara, Tanzania
| | - Johan L van Leeuwen
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Florian T Muijres
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands.
| |
Collapse
|
35
|
Smith NM, Balsalobre JB, Doshi M, Willenberg BJ, Dickerson AK. Landing mosquitoes bounce when engaging a substrate. Sci Rep 2020; 10:15744. [PMID: 32978447 PMCID: PMC7519040 DOI: 10.1038/s41598-020-72462-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 09/02/2020] [Indexed: 11/09/2022] Open
Abstract
In this experimental study we film the landings of Aedes aegypti mosquitoes to characterize landing behaviors and kinetics, limitations, and the passive physiological mechanics they employ to land on a vertical surface. A typical landing involves 1-2 bounces, reducing inbound momentum by more than half before the mosquito firmly attaches to a surface. Mosquitoes initially approach landing surfaces at 0.1-0.6 m/s, decelerating to zero velocity in approximately 5 ms at accelerations as high as 5.5 gravities. Unlike Dipteran relatives, mosquitoes do not visibly prepare for landing with leg adjustments or body pitching. Instead mosquitoes rely on damping by deforming two forelimbs and buckling of the proboscis, which also serves to distribute the impact force, lessening the potential of detection by a mammalian host. The rebound response of a landing mosquito is well-characterized by a passive mass-spring-damper model which permits the calculation of force across impact velocity. The landing force of the average mosquito in our study is approximately 40 [Formula: see text]N corresponding to an impact velocity of 0.24 m/s. The substrate contact velocity which produces a force perceptible to humans, 0.42 m/s, is above 85% of experimentally observed landing speeds.
Collapse
Affiliation(s)
- Nicholas M Smith
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, USA
| | - Jasmine B Balsalobre
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, USA
| | - Mona Doshi
- Department of Internal Medicine, College of Medicine, University of Central Florida, Orlando, USA
| | - Bradley J Willenberg
- Department of Internal Medicine, College of Medicine, University of Central Florida, Orlando, USA
| | - Andrew K Dickerson
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, USA.
| |
Collapse
|
36
|
Hol FJH, Lambrechts L, Prakash M. BiteOscope, an open platform to study mosquito biting behavior. eLife 2020; 9:e56829. [PMID: 32960173 PMCID: PMC7535929 DOI: 10.7554/elife.56829] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/05/2020] [Indexed: 01/16/2023] Open
Abstract
Female mosquitoes need a blood meal to reproduce, and in obtaining this essential nutrient they transmit deadly pathogens. Although crucial for the spread of mosquito-borne diseases, blood feeding remains poorly understood due to technological limitations. Indeed, studies often expose human subjects to assess biting behavior. Here, we present the biteOscope, a device that attracts mosquitoes to a host mimic which they bite to obtain an artificial blood meal. The host mimic is transparent, allowing high-resolution imaging of the feeding mosquito. Using machine learning, we extract detailed behavioral statistics describing the locomotion, pose, biting, and feeding dynamics of Aedes aegypti, Aedes albopictus, Anopheles stephensi, and Anopheles coluzzii. In addition to characterizing behavioral patterns, we discover that the common insect repellent DEET repels Anopheles coluzzii upon contact with their legs. The biteOscope provides a new perspective on mosquito blood feeding, enabling the high-throughput quantitative characterization of this lethal behavior.
Collapse
Affiliation(s)
- Felix JH Hol
- Department of Bioengineering, Stanford UniversityStanfordUnited States
- Insect-Virus Interactions Unit, Institut Pasteur, UMR2000, CNRSParisFrance
- Center for research and Interdisciplinarity, U1284 INSERM, Université de ParisParisFrance
| | - Louis Lambrechts
- Insect-Virus Interactions Unit, Institut Pasteur, UMR2000, CNRSParisFrance
| | - Manu Prakash
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| |
Collapse
|
37
|
Young BD, Escalon JA, Mathew D. Odors: from chemical structures to gaseous plumes. Neurosci Biobehav Rev 2020; 111:19-29. [PMID: 31931034 DOI: 10.1016/j.neubiorev.2020.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 01/07/2020] [Accepted: 01/07/2020] [Indexed: 10/25/2022]
Abstract
We are immersed within an odorous sea of chemical currents that we parse into individual odors with complex structures. Odors have been posited as determined by the structural relation between the molecules that compose the chemical compounds and their interactions with the receptor site. But, naturally occurring smells are parsed from gaseous odor plumes. To give a comprehensive account of the nature of odors the chemosciences must account for these large distributed entities as well. We offer a focused review of what is known about the perception of odor plumes for olfactory navigation and tracking, which we then connect to what is known about the role odorants play as properties of the plume in determining odor identity with respect to odor quality. We end by motivating our central claim that more research needs to be conducted on the role that odorants play within the odor plume in determining odor identity.
Collapse
Affiliation(s)
- Benjamin D Young
- Philosophy and Neuroscience, University of Nevada, 1664 N Virginia St, Reno, NV 89557, United States.
| | | | - Dennis Mathew
- Biology and Neuroscience, University of Nevada, Reno, United States.
| |
Collapse
|
38
|
Information limitation and the dynamics of coupled ecological systems. Nat Ecol Evol 2019; 4:82-90. [PMID: 31659309 DOI: 10.1038/s41559-019-1008-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/16/2019] [Indexed: 01/09/2023]
Abstract
The dynamics of large ecological systems result from vast numbers of interactions between individual organisms. Here, we develop mathematical theory to show that the rate of such interactions is inherently limited by the ability of organisms to gain information about one another. This phenomenon, which we call 'information limitation', is likely to be widespread in real ecological systems and can dictate both the rates of ecological interactions and long-run dynamics of interacting populations. We show how information limitation leads to sigmoid interaction rate functions that can stabilize antagonistic interactions and destabilize mutualistic ones; as a species or type becomes rare, information on its whereabouts also becomes rare, weakening coupling with consumers, pathogens and mutualists. This can facilitate persistence of consumer-resource systems, alter the course of pathogen infections within a host and enhance the rates of oceanic productivity and carbon export. Our findings may shed light on phenomena in many living systems where information drives interactions.
Collapse
|
39
|
Demers J, Bewick S, Calabrese J, Fagan WF. Dynamic modelling of personal protection control strategies for vector-borne disease limits the role of diversity amplification. J R Soc Interface 2019; 15:rsif.2018.0166. [PMID: 30135260 DOI: 10.1098/rsif.2018.0166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/30/2018] [Indexed: 11/12/2022] Open
Abstract
Personal protection measures, such as bed nets and repellents, are important tools for the suppression of vector-borne diseases like malaria and Zika, and the ability of health agencies to distribute protection and encourage its use plays an important role in the efficacy of community-wide disease management strategies. Recent modelling studies have shown that a counterintuitive diversity-driven amplification in community-wide disease levels can result from a population's partial adoption of personal protection measures, potentially to the detriment of disease management efforts. This finding, however, may overestimate the negative impact of partial personal protection as a result of implicit restrictive model assumptions regarding host compliance, access to and longevity of protection measures. We establish a new modelling methodology for incorporating community-wide personal protection distribution programmes in vector-borne disease systems which flexibly accounts for compliance, access, longevity and control strategies by way of a flow between protected and unprotected populations. Our methodology yields large reductions in the severity and occurrence of amplification effects as compared to existing models.
Collapse
Affiliation(s)
- Jeffery Demers
- Department of Biology, University of Maryland College Park, College Park, MD 20742, USA .,Conservation Ecology Center, Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Road, Front Royal, VA 22630, USA
| | - Sharon Bewick
- Department of Biology, University of Maryland College Park, College Park, MD 20742, USA
| | - Justin Calabrese
- Department of Biology, University of Maryland College Park, College Park, MD 20742, USA.,Conservation Ecology Center, Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Road, Front Royal, VA 22630, USA
| | - William F Fagan
- Department of Biology, University of Maryland College Park, College Park, MD 20742, USA
| |
Collapse
|
40
|
Hill SR, Ghaninia M, Ignell R. Blood Meal Induced Regulation of Gene Expression in the Maxillary Palps, a Chemosensory Organ of the Mosquito Aedes aegypti. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00336] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
41
|
Vinauger C, Van Breugel F, Locke LT, Tobin KKS, Dickinson MH, Fairhall AL, Akbari OS, Riffell JA. Visual-Olfactory Integration in the Human Disease Vector Mosquito Aedes aegypti. Curr Biol 2019; 29:2509-2516.e5. [PMID: 31327719 DOI: 10.1016/j.cub.2019.06.043] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/21/2019] [Accepted: 06/13/2019] [Indexed: 11/28/2022]
Abstract
Mosquitoes rely on the integration of multiple sensory cues, including olfactory, visual, and thermal stimuli, to detect, identify, and locate their hosts [1-4]. Although we increasingly know more about the role of chemosensory behaviors in mediating mosquito-host interactions [1], the role of visual cues is comparatively less studied [3], and how the combination of olfactory and visual information is integrated in the mosquito brain remains unknown. In the present study, we used a tethered-flight light-emitting diode (LED) arena, which allowed for quantitative control over the stimuli, and a control theoretic model to show that CO2 modulates mosquito steering responses toward vertical bars. To gain insight into the neural basis of this olfactory and visual coupling, we conducted two-photon microscopy experiments in a new GCaMP6s-expressing mosquito line. Imaging revealed that neuropil regions within the lobula exhibited strong responses to objects, such as a bar, but showed little response to a large-field motion. Approximately 20% of the lobula neuropil we imaged were modulated when CO2 preceded the presentation of a moving bar. By contrast, responses in the antennal (olfactory) lobe were not modulated by visual stimuli presented before or after an olfactory stimulus. Together, our results suggest that asymmetric coupling between these sensory systems provides enhanced steering responses to discrete objects.
Collapse
Affiliation(s)
- Clément Vinauger
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Floris Van Breugel
- Department of Mechanical Engineering, University of Nevada-Reno, Reno, NV 89557, USA
| | - Lauren T Locke
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Kennedy K S Tobin
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Michael H Dickinson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Adrienne L Fairhall
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Omar S Akbari
- Section of Cell and Developmental Biology, University of California, San Diego, San Diego, CA 92093, USA
| | - Jeffrey A Riffell
- Department of Biology, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
42
|
Cartography of odor chemicals in the dengue vector mosquito (Aedes aegypti L., Diptera/Culicidae). Sci Rep 2019; 9:8510. [PMID: 31186462 PMCID: PMC6559988 DOI: 10.1038/s41598-019-44851-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 05/23/2019] [Indexed: 11/29/2022] Open
Abstract
This study was aimed to identify the chemical compounds of Aedes aegypti that can be potentially used to develop pheromone-based vector control methods. In this study, we compared the chemical compounds collected from the organs of mosquitoes at different developmental stages in the life cycle. We also compared the composition and amount of extracts from the different tissues of male and female adult mosquito. Interestingly, we found large amount of C17-C20 ethyl and methyl esters in the wings of female and antennae of male mosquito. We also found that isopropyl esters, dodelactone, octadecenoic acid and medium-chain fatty acid increase drastically during the late larval stage (L4). Old adult mosquitoes showed remarkable increase in production of C16:1 and C18:1 methyl esters, as a first example of chemical signatures specifically associated with aging in the animals. This knowledge may open the ground to find new behaviorally-important molecules with the ability to control Aedes specifically.
Collapse
|
43
|
Sallam MF, Pereira RM, Batich C, Koehler P. Factors Affecting Short-Range Host-Seeking for the Yellow Fever Mosquito (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:609-616. [PMID: 30689913 DOI: 10.1093/jme/tjy230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Indexed: 06/09/2023]
Abstract
Understanding short-range cues (e.g., host odorants, heat, moisture) of host-seeking female Aedes aegypti L. is very important for attempts to reduce mosquito bites, to complement current control strategies, and to develop potential spatial repellents. We investigated behavior under semi-field conditions utilizing a new portable uni-port taxis box with a caged chicken host. The combined influences of airflow regimes (0, 1.5, 3, 5, and 6 m/s), distance from host odor (10, 50, 100 cm), host-odor confinement (partial confinement/unconfined), and foraging periodicity (day/evening) were studied. Statistical regression analysis was used to delineate the significant factors that predict upwind flight behavior and short-range source location. Almost 15% of host-seeking Ae. aegypti were activated by an unconfined chicken odor in still air. This was double the number of attracted mosquitoes to confined host odor. The maximum behavioral response was reported with airflow of 5 m/s during daytime (76.7% ± 2.85) at a distance of 10 (70.7% ± 2.47) and 50 cm (56.7% ± 8.88). However, airflow of 6 m/s activated host-seeking orientation during evening assays. The host-seeking response between indoor and outdoor experiments was not significantly different and demonstrated the reliability of the portable taxis box in evaluating mosquito short-range behavioral response toward hosts.
Collapse
Affiliation(s)
- Mohamed F Sallam
- New Orleans Mosquito, Termite, and Rodent Control Board, New Orleans, LA
| | - Roberto M Pereira
- Urban Entomology Laboratory, Entomology and Nematology Department, UF/IFAS, Gainesville, FL
| | - Chris Batich
- Materials Science and Engineering Department, UF, Gainesville, FL
| | - Philip Koehler
- Urban Entomology Laboratory, Entomology and Nematology Department, UF/IFAS, Gainesville, FL
| |
Collapse
|
44
|
Distinct activity-gated pathways mediate attraction and aversion to CO 2 in Drosophila. Nature 2018; 564:420-424. [PMID: 30464346 PMCID: PMC6314688 DOI: 10.1038/s41586-018-0732-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 10/11/2018] [Indexed: 12/18/2022]
Abstract
Carbon dioxide is produced by many organic processes, and is a convenient volatile cue for insects1 searching for blood hosts2, flowers3, communal nests4, fruit5, and wildfires6. Curiously, although Drosophila melanogaster feed on yeast that produce CO2 and ethanol during fermentation, laboratory experiments suggest that walking flies avoid CO27–12. Here, we resolve this paradox by showing that both flying and walking Drosophila find CO2 attractive, but only when in an active state associated with foraging. Aversion at low activity levels may be an adaptation to avoid CO2-seeking-parasites, or succumbing to respiratory acidosis in the presence of high concentrations of CO2 that exist in nature13,14. In contrast to CO2, flies are attracted to ethanol in all behavioral states, and invest twice the time searching near ethanol compared to CO2. These behavioral differences reflect the fact that whereas CO2 is generated by many natural processes, ethanol is a unique signature of yeast fermentation. Using genetic tools, we determined that the evolutionarily ancient ionotropic co-receptor IR25a is required for CO2 attraction, and that the receptors necessary for CO2 avoidance are not involved. Our study lays the foundation for future research to determine the neural circuits underlying both state- and odorant- dependent decision making in Drosophila.
Collapse
|
45
|
Cribellier A, van Erp JA, Hiscox A, Lankheet MJ, van Leeuwen JL, Spitzen J, Muijres FT. Flight behaviour of malaria mosquitoes around odour-baited traps: capture and escape dynamics. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180246. [PMID: 30225014 PMCID: PMC6124112 DOI: 10.1098/rsos.180246] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
Host-seeking mosquitoes rely on a range of sensory cues to find and approach blood hosts, as well as to avoid host detection. By using odour blends and visual cues that attract anthropophilic mosquitoes, odour-baited traps have been developed to monitor and control human pathogen-transmitting vectors. Although long-range attraction of such traps has already been studied thoroughly, close-range response of mosquitoes to these traps has been largely ignored. Here, we studied the flight behaviour of female malaria mosquitoes (Anopheles coluzzii) in the immediate vicinity of a commercially available odour-baited trap, positioned in a hanging and standing orientation. By analysing more than 2500 three-dimensional flight tracks, we elucidated how mosquitoes reacted to the trap, and how this led to capture. The measured flight dynamics revealed two distinct stereotypical behaviours: (i) mosquitoes that approached a trap tended to simultaneously fly downward towards the ground; (ii) mosquitoes that came close to a trap changed their flight direction by rapidly accelerating upward. The combination of these behaviours led to strikingly different flight patterns and capture dynamics, resulting in contrasting short-range attractiveness and capture mechanism of the oppositely oriented traps. These new insights may help in improving odour-baited traps, and consequently their contribution in global vector control strategies.
Collapse
Affiliation(s)
- Antoine Cribellier
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Jens A. van Erp
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Alexandra Hiscox
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands
| | - Martin J. Lankheet
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | | | - Jeroen Spitzen
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands
| | - Florian T. Muijres
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| |
Collapse
|
46
|
History dependence in insect flight decisions during odor tracking. PLoS Comput Biol 2018; 14:e1005969. [PMID: 29432454 PMCID: PMC5828511 DOI: 10.1371/journal.pcbi.1005969] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 02/27/2018] [Accepted: 01/07/2018] [Indexed: 11/19/2022] Open
Abstract
Natural decision-making often involves extended decision sequences in response to variable stimuli with complex structure. As an example, many animals follow odor plumes to locate food sources or mates, but turbulence breaks up the advected odor signal into intermittent filaments and puffs. This scenario provides an opportunity to ask how animals use sparse, instantaneous, and stochastic signal encounters to generate goal-oriented behavioral sequences. Here we examined the trajectories of flying fruit flies (Drosophila melanogaster) and mosquitoes (Aedes aegypti) navigating in controlled plumes of attractive odorants. While it is known that mean odor-triggered flight responses are dominated by upwind turns, individual responses are highly variable. We asked whether deviations from mean responses depended on specific features of odor encounters, and found that odor-triggered turns were slightly but significantly modulated by two features of odor encounters. First, encounters with higher concentrations triggered stronger upwind turns. Second, encounters occurring later in a sequence triggered weaker upwind turns. To contextualize the latter history dependence theoretically, we examined trajectories simulated from three normative tracking strategies. We found that neither a purely reactive strategy nor a strategy in which the tracker learned the plume centerline over time captured the observed history dependence. In contrast, "infotaxis", in which flight decisions maximized expected information gain about source location, exhibited a history dependence aligned in sign with the data, though much larger in magnitude. These findings suggest that while true plume tracking is dominated by a reactive odor response it might also involve a history-dependent modulation of responses consistent with the accumulation of information about a source over multi-encounter timescales. This suggests that short-term memory processes modulating decision sequences may play a role in natural plume tracking.
Collapse
|
47
|
Endo N, Eltahir EAB. Modelling and observing the role of wind in Anopheles population dynamics around a reservoir. Malar J 2018; 17:48. [PMID: 29370803 PMCID: PMC5784732 DOI: 10.1186/s12936-018-2197-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 01/19/2018] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Wind conditions, as well as other environmental conditions, are likely to influence malaria transmission through the behaviours of Anopheles mosquitoes, especially around water-resource reservoirs. Wind-induced waves in a reservoir impose mortality on aquatic-stage mosquitoes. Mosquitoes' host-seeking activity is also influenced by wind through dispersion of [Formula: see text]. However, no malaria transmission model exists to date that simulated those impacts of wind mechanistically. METHODS A modelling framework for simulating the three important effects of wind on the behaviours of mosquito is developed: attraction of adult mosquitoes through dispersion of [Formula: see text] ([Formula: see text] attraction), advection of adult mosquitoes (advection), and aquatic-stage mortality due to wind-induced surface waves (waves). The framework was incorporated in a mechanistic malaria transmission simulator, HYDREMATS. The performance of the extended simulator was compared with the observed population dynamics of the Anopheles mosquitoes at a village adjacent to the Koka Reservoir in Ethiopia. RESULTS The observed population dynamics of the Anopheles mosquitoes were reproduced with some reasonable accuracy in HYDREMATS that includes the representation of the wind effects. HYDREMATS without the wind model failed to do so. Offshore wind explained the increase in Anopheles population that cannot be expected from other environmental conditions alone. CONCLUSIONS Around large water bodies such as reservoirs, the role of wind in the dynamics of Anopheles population, hence in malaria transmission, can be significant. Modelling the impacts of wind on the behaviours of Anopheles mosquitoes aids in reproducing the seasonality of malaria transmission and in estimation of the risk of malaria around reservoirs.
Collapse
Affiliation(s)
- Noriko Endo
- Ralph M. Parsons Laboratory, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, USA.
| | - Elfatih A B Eltahir
- Ralph M. Parsons Laboratory, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, USA
| |
Collapse
|
48
|
Shcherbacheva A, Haario H, Killeen GF. Modeling host-seeking behavior of African malaria vector mosquitoes in the presence of long-lasting insecticidal nets. Math Biosci 2017; 295:36-47. [PMID: 29031707 DOI: 10.1016/j.mbs.2017.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 05/14/2017] [Accepted: 10/08/2017] [Indexed: 11/24/2022]
Abstract
The efficiency of spatial repellents and long-lasting insecticide-treated nets (LLINs) is a key research topic in malaria control. Insecticidal nets reduce the mosquito-human contact rate and simultaneously decrease mosquito populations. However, LLINs demonstrate dissimilar efficiency against different species of malaria mosquitoes. Various factors have been proposed as an explanation, including differences in insecticide-induced mortality, flight characteristics, or persistence of attack. Here we present a discrete agent-based approach that enables the efficiency of LLINs, baited traps and Insecticide Residual Sprays (IRS) to be examined. The model is calibrated with hut-level experimental data to compare the efficiency of protection against two mosquito species: Anopheles gambiae and Anopheles arabiensis. We show that while such data does not allow an unambiguous identification of the details of how LLINs alter the vector behavior, the model calibrations quantify the overall impact of LLINs for the two different mosquito species. The simulations are generalized to community-scale scenarios that systematically demonstrate the lower efficiency of the LLINs in control of An. arabiensis compared to An. gambiae.
Collapse
Affiliation(s)
- Anna Shcherbacheva
- LUT School of Engineering Science, Lappeenranta University of Technology, Lappeenranta, Finland.
| | - Heikki Haario
- LUT School of Engineering Science, Lappeenranta University of Technology, Lappeenranta, Finland.
| | - Gerry F Killeen
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Ifakara, Morogoro, United Republic of Tanzania; Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.
| |
Collapse
|
49
|
Majeed S, Hill SR, Dekker T, Ignell R. Detection and perception of generic host volatiles by mosquitoes: responses to CO 2 constrains host-seeking behaviour. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170189. [PMID: 28573028 PMCID: PMC5451829 DOI: 10.1098/rsos.170189] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/11/2017] [Indexed: 05/20/2023]
Abstract
Natural selection has favoured specialization in anthropophilic mosquito host choice, yet in the absence of human hosts, females feed on a selected range of vertebrates. For host recognition, we hypothesize that mosquitoes primarily rely on generic host volatiles. Detection and perception of such compounds would provide the mosquito with a flexible, yet constrained, odour coding system that could delineate host preference. In this study, we show that the quintessential generic volatile for host-seeking, carbon dioxide, activates and attracts the malaria mosquito, Anopheles coluzzii, and the arbovirus vectors, Aedes aegypti and Culex quinquefasciatus, within boundaries set by the dynamic range and coding capacity of the CO2-sensitive olfactory receptor neurons. These boundaries are sufficiently broad to elicit behavioural responses to various hosts within their preferred host range. This study highlights the significance of the sensitivity of the carbon dioxide detection system and its regulation of host seeking and recognition.
Collapse
|
50
|
Raji JI, DeGennaro M. Genetic Analysis of Mosquito Detection of Humans. CURRENT OPINION IN INSECT SCIENCE 2017; 20:34-38. [PMID: 28428935 PMCID: PMC5393449 DOI: 10.1016/j.cois.2017.03.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Mosquitoes detect the presence of humans by integrating chemosensory, thermal, and visual cues. Among these, odors are crucial for mosquito host detection. Insects have evolved a diverse repertoire of receptors to detect their plant and animal hosts. Genetic analysis of these receptors in Drosophila has set the stage for similar studies in mosquitoes. The diversity of the cues involved in mosquito host-seeking has made designing behavioral control strategies a challenge. The sensory receptors that are most important for mosquito detection of humans can now be determined using genome editing. Here, we will review our current understanding of the salient cues that attract mosquitoes, their receptors, and suggest ways forward for novel olfaction-based vector control strategies.
Collapse
Affiliation(s)
- Joshua I. Raji
- Biomolecular Sciences Institute & Department of Biological Sciences, Florida International University, Miami, FL USA
| | - Matthew DeGennaro
- Biomolecular Sciences Institute & Department of Biological Sciences, Florida International University, Miami, FL USA
| |
Collapse
|