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Baltiansky L, Frankel G, Feinerman O. Emergent regulation of ant foraging frequency through a computationally inexpensive forager movement rule. eLife 2023; 12:77659. [PMID: 37067884 PMCID: PMC10110237 DOI: 10.7554/elife.77659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 02/06/2023] [Indexed: 04/18/2023] Open
Abstract
Ant colonies regulate foraging in response to their collective hunger, yet the mechanism behind this distributed regulation remains unclear. Previously, by imaging food flow within ant colonies we showed that the frequency of foraging events declines linearly with colony satiation (Greenwald et al., 2018). Our analysis implied that as a forager distributes food in the nest, two factors affect her decision to exit for another foraging trip: her current food load and its rate of change. Sensing these variables can be attributed to the forager's individual cognitive ability. Here, new analyses of the foragers' trajectories within the nest imply a different way to achieve the observed regulation. Instead of an explicit decision to exit, foragers merely tend toward the depth of the nest when their food load is high and toward the nest exit when it is low. Thus, the colony shapes the forager's trajectory by controlling her unloading rate, while she senses only her current food load. Using an agent-based model and mathematical analysis, we show that this simple mechanism robustly yields emergent regulation of foraging frequency. These findings demonstrate how the embedding of individuals in physical space can reduce their cognitive demands without compromising their computational role in the group.
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Affiliation(s)
- Lior Baltiansky
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Guy Frankel
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Ofer Feinerman
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
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Penn HJ, Simone-Finstrom MD, de Guzman LI, Tokarz PG, Dickens R. Colony-Level Viral Load Influences Collective Foraging in Honey Bees. FRONTIERS IN INSECT SCIENCE 2022; 2:894482. [PMID: 38468777 PMCID: PMC10926460 DOI: 10.3389/finsc.2022.894482] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/13/2022] [Indexed: 03/13/2024]
Abstract
Nutrition is an important component of social insect colony health especially in the face of stressors such as parasitism and viral infections. Honey bees are known to preferentially select nectar and pollen based on macronutrient and phytochemical contents and in response to pathogen loads. However, given that honey bees live in colonies, collective foraging decisions may be impacted directly by forager infection status but also by colony health. This field experiment was conducted to determine if honey bee viral infections are correlated with pollen and nectar foraging and if these associations are impacted more by colony or forager infection. By comparing regressions with and without forager and colony variables and through structural equation models, we were able to determine the relative contributions of colony and forager virus loads on forager decisions. We found that foragers had higher numbers and levels of BQCV and CBPV but lower levels of DWV viruses than their respective colonies. Overall, individuals appeared to forage based a combination of their own and colony health but with greater weight given to colony metrics. Colony parasitism by Varroa mites, positively correlated with both forager and colony DWV-B levels, was negatively associated with nectar weight. Further, colony DWV-B levels were negatively associated with individually foraged pollen protein: lipid ratios but positively correlated with nectar weight and sugar content. This study shows that both colony and forager health can simultaneously mediate individual foraging decisions and that the importance of viral infections and parasite levels varies with foraging metrics. Overall, this work highlights the continued need to explore the interactions of disease, nutrition, and genetics in social interactions and structures.
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Affiliation(s)
- Hannah J. Penn
- USDA ARS, Sugarcane Research Unit, Houma, LA, United States
| | - Michael D. Simone-Finstrom
- USDA ARS, Honey Bee Breeding, Genetics and Physiology Research Laboratory, Baton Rouge, LA, United States
| | - Lilia I. de Guzman
- USDA ARS, Honey Bee Breeding, Genetics and Physiology Research Laboratory, Baton Rouge, LA, United States
| | - Philip G. Tokarz
- USDA ARS, Honey Bee Breeding, Genetics and Physiology Research Laboratory, Baton Rouge, LA, United States
| | - Rachel Dickens
- USDA ARS, Honey Bee Breeding, Genetics and Physiology Research Laboratory, Baton Rouge, LA, United States
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Favaro R, Roved J, Haase A, Angeli S. Impact of Chronic Exposure to Two Neonicotinoids on Honey Bee Antennal Responses to Flower Volatiles and Pheromonal Compounds. FRONTIERS IN INSECT SCIENCE 2022; 2:821145. [PMID: 38468759 PMCID: PMC10926470 DOI: 10.3389/finsc.2022.821145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/18/2022] [Indexed: 03/13/2024]
Abstract
Volatile compounds provide important olfactory cues for honey bees (Apis mellifera L.), which are essential for their ecology, behavior, and social communication. In the external environment bees locate food sources by the use of floral scents, while inside the hive, pheromones such as the queen mandibular pheromone (QMP) and alarm pheromones serve important functions in regulating colony life and inducing aggressive responses against intruders and parasites. Widely reported alterations of various behaviors in- and outside the hive following exposure to pesticides could therefore be associated with a disturbance of odor sensitivity. In the present study, we tested the effects of neonicotinoid pesticides at field concentrations on the ability of honey bees to perceive volatiles at the very periphery of the olfactory system. Bee colonies were subjected to treatments during the summer with either Imidacloprid or Thiacloprid at sublethal concentrations. Antennal responses to apple (Malus domestica L.) flower volatiles were studied by GC-coupled electro-antennographic detection (GC-EAD), and a range of volatiles, a substitute of the QMP, and the alarm pheromone 2-heptanone were tested by electroantennography (EAG). Short-term and long-term effects of the neonicotinoid treatments were investigated on bees collected in the autumn and again in the following spring. Treatment with Thiacloprid induced changes in antennal responses to specific flower VOCs, with differing short- and long-term effects. In the short term, increased antennal responses were observed for benzyl-alcohol and 1-hexanol, which are common flower volatiles but also constituents of the honey bee sting gland secretions. The treatment with Thiacloprid also affected antennal responses to the QMP and the mandibular alarm pheromone 2-heptanone. In the short term, a faster signal degeneration of the response signal to the positive control citral was recorded in the antennae of bees exposed to Thiacloprid or Imidacloprid. Finally, we observed season-related differences in the antennal responses to multiple VOCs. Altogether, our results suggest that volatile-specific alterations of antennal responses may contribute to explaining several behavioral changes previously observed in neonicotinoid-exposed bees. Treatment effects were generally more prominent in the short term, suggesting that adverse effects of neonicotinoid exposure may not persist across generations.
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Affiliation(s)
- Riccardo Favaro
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy
| | - Jacob Roved
- Section for Evolutionary Genomics, Faculty of Health and Medical Sciences, GLOBE Institute, University of Copenhagen, Copenhagen, Denmark
| | - Albrecht Haase
- Center for Mind/Brain Science (CIMeC), University of Trento, Rovereto, Italy
- Department of Physics, University of Trento, Povo, Italy
| | - Sergio Angeli
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy
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Walsh EM, Khan O, Grunseich J, Helms AM, Ing NH, Rangel J. Pesticide Exposure During Development Does Not Affect the Larval Pheromones, Feeding Rates, or Morphology of Adult Honey Bee (Apis mellifera) Queens. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.681506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Recent work demonstrated that honey bee (Apis mellifera L.) queens reared in pesticide-laden beeswax exhibit significant changes in the composition of the chemicals produced by their mandibular glands including those that comprise queen mandibular pheromone, which is a critical signal used in mating as well as queen tending behavior. For the present study, we hypothesized that pesticide exposure during development would alter other queen-produced chemicals, including brood pheromone in immature queens, thus resulting in differential feeding of queen larvae by nurse workers, ultimately impacting adult queen morphology. We tested these hypotheses by rearing queens in beeswax containing field-relevant concentrations of (1) a combination of tau-fluvalinate and coumaphos, (2) amitraz, or (3) a combination of chlorothalonil and chlorpyrifos. These pesticides are ubiquitous in most commercial beekeeping operations in North America. We observed nurse feeding rates of queen larvae grafted into pesticide-laden beeswax, analyzed the chemical composition of larval queen pheromones and measured morphological markers in adult queens. Neither the nurse feeding rates, nor the chemical profiles of immature queen pheromones, differed significantly between queens reared in pesticide-laden wax compared to queens reared in pesticide-free wax. Moreover, pesticide exposure during development did not cause virgin or mated adult queens to exhibit differences in morphological markers (i.e., body weight, head width, or thorax width). These results were unexpected given our previous research and indicate that future work is needed to fully understand how pesticide exposure during development affects honey bee queen physiology, as well as how various adult queen quality metrics relate to each other.
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Gillanders RN, Glackin JM, Babić Z, Muštra M, Simić M, Kezić N, Turnbull GA, Filipi J. Biomonitoring for wide area surveying in landmine detection using honeybees and optical sensing. CHEMOSPHERE 2021; 273:129646. [PMID: 33493813 DOI: 10.1016/j.chemosphere.2021.129646] [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: 11/26/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
Humanitarian demining is a worldwide effort and the range of climates and environments prevent any one detection method being suitable for all sites, so more tools are required for safe and efficient explosives sensing. Landmines emit a chemical flux over time, and honeybees can collect the trace residues of explosives (as particles or as vapour) on their body hairs. This capability was exploited using a passive method allowing the honeybees to freely forage in a mined area, where trace explosives present in the environment stuck to the honeybee body, which were subsequently transferred onto an adsorbent material for analysis by a fluorescent polymer sensor. Potential false positive sources were investigated, namely common bee pheromones, the anti-varroa pesticide Amitraz, and the environment around a clean apiary, and no significant response was found to any from the sensor. The mined site gave a substantial response in the optical sensor films, with quenching efficiencies of up to 38%. A model was adapted to estimate the mass of explosives returned to the colony, which may be useful for estimating the number of mines in a given area.
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Affiliation(s)
- Ross N Gillanders
- Organic Semiconductor Centre, SUPA, School of Physics & Astronomy, University of St Andrews, Fife, KY16 9SS, Scotland.
| | - James Me Glackin
- Organic Semiconductor Centre, SUPA, School of Physics & Astronomy, University of St Andrews, Fife, KY16 9SS, Scotland
| | - Zdenka Babić
- Faculty of Electrical Engineering, University of Banja Luka, Patre 5, 78000, Banja Luka, Bosnia and Herzegovina
| | - Mario Muštra
- University of Zagreb, Faculty of Transport and Traffic Sciences, Vukelićeva 4, HR, 10000, Zagreb, Croatia
| | - Mitar Simić
- Faculty of Electrical Engineering, University of Banja Luka, Patre 5, 78000, Banja Luka, Bosnia and Herzegovina
| | - Nikola Kezić
- University of Zagreb, Faculty of Agriculture, Svetošimunska Cesta 25, 10000, Zagreb, Croatia
| | - Graham A Turnbull
- Organic Semiconductor Centre, SUPA, School of Physics & Astronomy, University of St Andrews, Fife, KY16 9SS, Scotland
| | - Janja Filipi
- Department of Ecology, Agronomy and Aquaculture, University of Zadar, Trg Kneza Višeslava 9, 23000, Zadar, Croatia.
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Foraging and feeding are independently regulated by social and personal hunger in the clonal raider ant. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-02985-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Light M, Shutler D, Cutler GC, Hillier NK. Varroa destructor mite electrophysiological responses to honey bee (Apis mellifera) colony volatiles. EXPERIMENTAL & APPLIED ACAROLOGY 2020; 81:495-514. [PMID: 32700265 DOI: 10.1007/s10493-020-00519-w] [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: 07/29/2019] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
Detection and interpretation of chemical cues is essential for Varroa destructor Anderson and Trueman, an important parasite of honey bees (Apis mellifera L.), to complete its life cycle. We collected volatiles from honey bee brood at various developmental stages and screened for V. destructor electrophysiological responses to these with gas chromatography-linked electrotarsal detection. Volatile collections contained several methyl-alkanes that evoked electrophysiological responses from V. destructor. Moreover, odors in honey bee colonies that regulate honey bee colony structure and function were also detected by V. destructor. Collections from mid- to late-stage larvae had detectable levels of low-volatility odors identified as components of the honey bee brood pheromone and branched alkanes likely originating from brood cuticle. Among these, several mid- to heavy-molecular weight compounds elicited high proportional electrophysiological responses by V. destructor relative to their abundance but could not be identified using chemical standards of previously documented honey bee brood odors. We suggest further investigation of these unknown volatiles and future behavioral assays to determine attractiveness/repellency (valence) of those identified through chemical standards.
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Affiliation(s)
- Michael Light
- Department of Biology, Acadia University, Wolfville, NS, B4P 2R6, Canada.
| | - Dave Shutler
- Department of Biology, Acadia University, Wolfville, NS, B4P 2R6, Canada
| | - G Christopher Cutler
- Department of Plant, Food, and Environmental Sciences, Dalhousie University, PO Box 550, Truro, NS, B2N 5E3, Canada
| | - N Kirk Hillier
- Department of Biology, Acadia University, Wolfville, NS, B4P 2R6, Canada
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Ma R, Rangel J, Grozinger CM. Honey bee (Apis mellifera) larval pheromones may regulate gene expression related to foraging task specialization. BMC Genomics 2019; 20:592. [PMID: 31324147 PMCID: PMC6642498 DOI: 10.1186/s12864-019-5923-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 06/21/2019] [Indexed: 12/22/2022] Open
Abstract
Background Foraging behavior in honey bees (Apis mellifera) is a complex phenotype that is regulated by physiological state and social signals. How these factors are integrated at the molecular level to modulate foraging behavior has not been well characterized. The transition of worker bees from nursing to foraging behaviors is mediated by large-scale changes in brain gene expression, which are influenced by pheromones produced by the queen and larvae. Larval pheromones can also stimulate foragers to leave the colony to collect pollen. However, the mechanisms underpinning this rapid behavioral plasticity in foragers that specialize in collecting pollen over nectar, and how larval pheromones impact these different behavioral states, remains to be determined. Here, we investigated the patterns of gene expression related to rapid behavioral plasticity and task allocation among honey bee foragers exposed to two larval pheromones, brood pheromone (BP) and (E)-beta-ocimene (EBO). We hypothesized that both pheromones would alter expression of genes in the brain related to foraging and would differentially impact brain gene expression depending on foraging specialization. Results Combining data reduction, clustering, and network analysis methods, we found that foraging preference (nectar vs. pollen) and pheromone exposure are each associated with specific brain gene expression profiles. Furthermore, pheromone exposure has a strong transcriptional effect on genes that are preferentially expressed in nectar foragers. Representation factor analysis between our study and previous landmark honey bee transcriptome studies revealed significant overlaps for both pheromone communication and foraging task specialization. Conclusions Our results suggest that, as social signals, pheromones alter expression patterns of foraging-related genes in the bee’s brain to increase pollen foraging at both long and short time scales. These results provide new insights into how social signals and task specialization are potentially integrated at the molecular level, and highlights the possible role that brain gene expression may play in honey bee behavioral plasticity across time scales. Electronic supplementary material The online version of this article (10.1186/s12864-019-5923-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rong Ma
- Department of Entomology, Center for Pollinator Research, Center for Chemical Ecology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA.
| | - Juliana Rangel
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Center for Chemical Ecology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
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Foraging and homing behavior of honey bees (Apis mellifera) during a total solar eclipse. Naturwissenschaften 2019; 106:4. [PMID: 30617515 DOI: 10.1007/s00114-018-1597-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 11/05/2018] [Accepted: 11/26/2018] [Indexed: 01/30/2023]
Abstract
Exceptional natural phenomena, such as those that occur during a total solar eclipse, provide unique opportunities to study animal behavior outside the naturally evolved context, which can be informative in more general terms. Circumstantial descriptions of abnormal animal behavior during solar eclipses abound, although scientific studies conducted during an eclipse are relatively rare due to inherent logistical difficulties. Here, honey bee foraging and homing behavior were studied during the total solar eclipse of August 21, 2017. In the first experiment, we studied foraging behavior of honey bees during the progression of the solar eclipse and found that the foraging activity drastically decreased but did not completely cease during the totality of the eclipse, in contrast to previous reports of complete cessation. The data indicate that the level of ambient light can largely overrule the internal circadian rhythm of foraging honey bees. Furthermore, colonies with a higher need for foraging decreased their foraging activity less than satiated colonies, consistent with the hypothesis that individual foraging decisions may be influenced by colony state, which affects cost-benefit analyses. In a second experiment, the temporal dynamics of homing of released workers and drones was compared in periods before, during, and after the solar eclipse. During the totality of the eclipse, very few bees arrived back at their hive, while homing before the total eclipse was accelerated, particularly in drones. The results suggest that, while the homing abilities of honey bees are not compromised until the sun is completely eclipsed, they may still interpret the diminishing light as an indicator of deteriorating flight conditions. Our unique study provides some insight into the control of honey bee foraging behavior when external cues and internal circadian rhythms are at odds, lent support to the notion that food deprivation can lead to riskier foraging, and indicated that homing in honey bees is possible even with very small amounts of sunlight.
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