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Balogh A, Kúdela M. Brighteness-dependent visual attractiveness of the human body for horse flies (Diptera: Tabanidae): a field experiment. JOURNAL OF MEDICAL ENTOMOLOGY 2024:tjae104. [PMID: 39182230 DOI: 10.1093/jme/tjae104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 07/24/2024] [Accepted: 08/08/2024] [Indexed: 08/27/2024]
Abstract
The landing patterns of blood-sucking females (Diptera: Tabanidae) are largely influenced by their visual perceptions. When attacking humans, the shape of different body parts and overall brightness of the body could be the factors determining the place of blood-sucking. The visual attractiveness of the human body for tabanids was investigated through a black and a white mannequin in the Danube floodplain, Slovakia. The mannequins were covered by glue once a week. On both of the mannequins, 332 horse flies were stuck. The trapped horse flies on the mannequins belong to the genera Tabanus Linnaeus, 1758, Hybomitra Enderlein, 1922, Chrysops Meigen, 1803, Haematopota Linnaeus, 1758 and Atylotus (Linnaeus, 1767). Based on the trapped tabanids, the black mannequin is 6.06 times more attractive than the white one. The most tabanid carcasses were found on the lower limbs (56.32%) and the least occurred on the head (2.1%), the difference in their occurrence between the lower limbs and head of both mannequins was significant (P < 0.001). A similar significant difference was observed on certain parts of both mannequins on the taxonomical level of the genera Tabanus, Hybomitra, and Atylotus, the carcasses of which aggregated mostly on the lower limbs, rather than on the upper limbs and head.
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Affiliation(s)
- Attila Balogh
- Department of Zoology, Comenius University in Bratislava, Ilkovičova 6, Bratislava, Slovakia
| | - Matúš Kúdela
- Department of Zoology, Comenius University in Bratislava, Ilkovičova 6, Bratislava, Slovakia
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2
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Doherty JF, Ames T, Brewster LI, Chiang J, Cyr E, Kelsey CR, Lee JP, Liu B, Lo IHY, Nirwal GK, Mohammed YG, Phelan O, Seyfourian P, Shannon DM, Tochor NK, Matthews BJ. An update and review of arthropod vector sensory systems: Potential targets for behavioural manipulation by parasites and other disease agents. ADVANCES IN PARASITOLOGY 2024; 124:57-89. [PMID: 38754927 DOI: 10.1016/bs.apar.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
For over a century, vector ecology has been a mainstay of vector-borne disease control. Much of this research has focused on the sensory ecology of blood-feeding arthropods (black flies, mosquitoes, ticks, etc.) with terrestrial vertebrate hosts. Of particular interest are the cues and sensory systems that drive host seeking and host feeding behaviours as they are critical for a vector to locate and feed from a host. An important yet overlooked component of arthropod vector ecology are the phenotypic changes observed in infected vectors that increase disease transmission. While our fundamental understanding of sensory mechanisms in disease vectors has drastically increased due to recent advances in genome engineering, for example, the advent of CRISPR-Cas9, and high-throughput "big data" approaches (genomics, proteomics, transcriptomics, etc.), we still do not know if and how parasites manipulate vector behaviour. Here, we review the latest research on arthropod vector sensory systems and propose key mechanisms that disease agents may alter to increase transmission.
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Affiliation(s)
| | - Tahnee Ames
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | | | - Jonathan Chiang
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Elsa Cyr
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Cameron R Kelsey
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Jeehan Phillip Lee
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Bingzong Liu
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Ivan Hok Yin Lo
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Gurleen K Nirwal
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | | | - Orna Phelan
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Parsa Seyfourian
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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3
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Beck M, Althaus V, Pegel U, Homberg U. Neurons sensitive to non-celestial polarized light in the brain of the desert locust. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:907-928. [PMID: 36809566 PMCID: PMC10643347 DOI: 10.1007/s00359-023-01618-w] [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: 05/31/2022] [Revised: 01/20/2023] [Accepted: 02/04/2023] [Indexed: 02/23/2023]
Abstract
Owing to alignment of rhodopsin in microvillar photoreceptors, insects are sensitive to the oscillation plane of polarized light. This property is used by many species to navigate with respect to the polarization pattern of light from the blue sky. In addition, the polarization angle of light reflected from shiny surfaces such as bodies of water, animal skin, leaves, or other objects can enhance contrast and visibility. Whereas photoreceptors and central mechanisms involved in celestial polarization vision have been investigated in great detail, little is known about peripheral and central mechanisms of sensing the polarization angle of light reflected from objects and surfaces. Desert locusts, like other insects, use a polarization-dependent sky compass for navigation but are also sensitive to polarization angles from horizontal directions. In order to further analyze the processing of polarized light reflected from objects or water surfaces, we tested the sensitivity of brain interneurons to the angle of polarized blue light presented from ventral direction in locusts that had their dorsal eye regions painted black. Neurons encountered interconnect the optic lobes, invade the central body, or send descending axons to the ventral nerve cord but are not part of the polarization vision pathway involved in sky-compass coding.
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Affiliation(s)
- Marius Beck
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany
- Institute of Biology, University of Siegen, 57068, Siegen, Germany
| | - Vanessa Althaus
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany
| | - Uta Pegel
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany.
- Center for Mind Brain and Behavior (CMBB), Philipps-University of Marburg and Justus Liebig University of Giessen, 35032, Marburg, Germany.
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4
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Blake AJ, Hung E, To S, Ng G, Qian J, Gries G. Stable flies sense and behaviorally respond to the polarization of light. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:885-897. [PMID: 37083716 DOI: 10.1007/s00359-023-01624-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/09/2023] [Accepted: 03/01/2023] [Indexed: 04/22/2023]
Abstract
Insects use their polarization-sensitive photoreceptors in a variety of ecological contexts including host-foraging. Here, we investigated the effect of polarized light on host foraging by the blood-feeding stable fly, Stomoxys calcitrans, a pest of livestock. Electroretinogram recordings with chromatic adaptation demonstrated that the spectral sensitivity of stable flies resembles that of other calyptrate flies. Histological studies of the flies' compound eye revealed differences in microvillar arrangement of ommatidial types, assumed to be pale and yellow, with the yellow R7 and pale R8 photoreceptors having the greatest polarization sensitivity. In behavioural experiments, stable flies preferred to alight on horizontally polarized stimuli with a high degree of linear polarization. This preferential response disappeared when either ultraviolet (UV) or human-visible wavelengths were omitted from light stimuli. Removing specific wavelength bands further revealed that the combination of UV (330-400 nm) and blue (400-525 nm) wavelength bands was sufficient to enable polarized light discrimination by flies. These findings enhance our understanding of polarization vision and foraging behavior among hematophagous insects and should inform future trap designs.
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Affiliation(s)
- Adam J Blake
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.
- Department of Biology, University of Washington, Seattle, WA, USA.
| | - Emmanuel Hung
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Stephanie To
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Geoffrey Ng
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - James Qian
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Gerhard Gries
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
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Caro T, Fogg E, Stephens-Collins T, Santon M, How MJ. Why don't horseflies land on zebras? J Exp Biol 2023; 226:286760. [PMID: 36700395 PMCID: PMC10088525 DOI: 10.1242/jeb.244778] [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: 07/14/2022] [Accepted: 01/12/2023] [Indexed: 01/27/2023]
Abstract
Stripes deter horseflies (tabanids) from landing on zebras and, while several mechanisms have been proposed, these hypotheses have yet to be tested satisfactorily. Here, we investigated three possible visual mechanisms that could impede successful tabanid landings (aliasing, contrast and polarization) but additionally explored pattern element size employing video footage of horseflies around differently patterned coats placed on domestic horses. We found that horseflies are averse to landing on highly but not on lightly contrasting stripes printed on horse coats. We could find no evidence for horseflies being attracted to coats that better reflected polarized light. Horseflies were somewhat less attracted to regular than to irregular check patterns, but this effect was not large enough to support the hypothesis of disrupting optic flow through aliasing. More likely it is due to attraction towards larger dark patches present in the irregular check patterns, an idea bolstered by comparing landings to the size of dark patterns present on the different coats. Our working hypothesis for the principal anti-parasite features of zebra pelage are that their stripes are sharply outlined and thin because these features specifically eliminate the occurrence of large monochrome dark patches that are highly attractive to horseflies at close distances.
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Affiliation(s)
- Tim Caro
- School of Biological Sciences, 24 Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, UK
| | - Eva Fogg
- School of Biological Sciences, 24 Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, UK
| | | | - Matteo Santon
- School of Biological Sciences, 24 Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, UK
| | - Martin J How
- School of Biological Sciences, 24 Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, UK
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6
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Zebras of all stripes repel biting flies at close range. Sci Rep 2022; 12:18617. [PMID: 36329147 PMCID: PMC9633588 DOI: 10.1038/s41598-022-22333-7] [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: 06/03/2022] [Accepted: 10/13/2022] [Indexed: 11/05/2022] Open
Abstract
The best-supported hypothesis for why zebras have stripes is that stripes repel biting flies. While this effect is well-established, the mechanism behind it remains elusive. Myriad hypotheses have been suggested, but few experiments have helped narrow the field of possible explanations. In addition, the complex visual features of real zebra pelage and the natural range of stripe widths have been largely left out of experimental designs. In paired-choice field experiments in a Kenyan savannah, we found that hungry Stomoxys flies released in an enclosure strongly preferred to land on uniform tan impala pelts over striped zebra pelts but exhibited no preference between the pelts of the zebra species with the widest stripes and the narrowest stripes. Our findings confirm that zebra stripes repel biting flies under naturalistic conditions and do so at close range (suggesting that several of the mechanisms hypothesized to operate at a distance are unnecessary for the fly-repulsion effect) but indicate that interspecific variation in stripe width is associated with selection pressures other than biting flies.
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Mihok S, Carlson DA. New materials for improving catches of horseflies (Diptera: Tabanidae) in Nzi traps. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:580-594. [PMID: 34145598 DOI: 10.1111/mve.12535] [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: 01/21/2021] [Revised: 05/01/2021] [Accepted: 06/03/2021] [Indexed: 06/12/2023]
Abstract
New materials in 85 configurations were tested relative to standard fabric Nzi traps to improve catches of tabanids based on artificial visual cues that mimic those used in nature for locating hosts or water. Colour-fast synthetic fabrics and photo-selective horticultural mesh were tested to facilitate insecticide impregnation and for improved durability. Many plastics were explored to document how flies react to polarized and visible vs. ultraviolet light. Lastly, sticky horizontal, linearly polarizing ground-level shiny plastic targets were tested for capturing water-seeking tabanids relative to traps and vertical fabric targets. Based on the capture of 281 786 female Tabanidae (Tabanus Linnaeus, Hybomitra Enderlein, Chrysops Meigen), four alternative formats provided higher catches and/or durability. They were substituting: (1) phthalogen turquoise for phthalogen blue, (2) solution-dyed fabrics for blue and black cotton, (3) clear/white horticultural mesh for mosquito netting, and (4) clear, reflective plastic for some or all netting. A Sunbrella/BioNet fabric trap (portable) and a blue-black Plexiglas®/netting trap (fixed applications) consistently performed best (1.5-3 × higher catches). Ground-level targets captured many male and gravid female Hybomitra but were ineffective for Tabanus. Traps and vertical fabric or transparent sticky targets captured mainly unfed females.
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Affiliation(s)
- S Mihok
- Independent Scientist, Russell, Ontario, Canada
| | - D A Carlson
- University of Florida Courtesy Assistant Professor Entomology and Nematology, Gainesville, FL, U.S.A
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Stavenga DG. The wing scales of the mother-of-pearl butterfly, Protogoniomorpha parhassus, are thin film reflectors causing strong iridescence and polarization. J Exp Biol 2021; 224:271006. [PMID: 34291802 PMCID: PMC8353264 DOI: 10.1242/jeb.242983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/16/2021] [Indexed: 11/20/2022]
Abstract
The dorsal wings of the mother-of-pearl butterfly, Protogoniomorpha parhassus, display an angle-dependent pink, structural color. This effect is created by light interference in the lower lamina of the wing scales, which acts as an optical thin film. The scales feature extremely large windows that enhance the scale reflectance, because the upper lamina of ridges and cross-ribs is very sparse. Characteristic for thin film reflectors, the spectral shape of the reflected light strongly depends on the angle of light incidence, shifting from pink to yellow when changing the angles of illumination and observation from normal to skew, and also the degree of polarization strongly varies. The simultaneous spectral and polarization changes serve a possibly widespread, highly effective system among butterflies for intraspecific communication during flight. Summary: The dorsal wings of the mother-of-pearl butterfly, Protogoniomorpha parhassus, show characteristics of thin film reflectors, allowing simultaneous spectral and polarization changes, which may be important in intraspecific communication.
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Affiliation(s)
- Doekele G Stavenga
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
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9
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Santer RD, Okal MN, Esterhuizen J, Torr SJ. Evaluation of improved coloured targets to control riverine tsetse in East Africa: A Bayesian approach. PLoS Negl Trop Dis 2021; 15:e0009463. [PMID: 34153040 PMCID: PMC8216509 DOI: 10.1371/journal.pntd.0009463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 05/11/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Riverine tsetse (Glossina spp.) transmit Trypanosoma brucei gambiense which causes Gambian Human African Trypanosomiasis. Tiny Targets were developed for cost-effective riverine tsetse control, and comprise panels of insecticide-treated blue polyester fabric and black net that attract and kill tsetse. Versus typical blue polyesters, two putatively more attractive fabrics have been developed: Vestergaard ZeroFly blue, and violet. Violet was most attractive to savannah tsetse using large targets, but neither fabric has been tested for riverine tsetse using Tiny Targets. METHODS We measured numbers of G. f. fuscipes attracted to electrified Tiny Targets in Kenya and Uganda. We compared violets, Vestergaard blues, and a typical blue polyester, using three replicated Latin squares experiments. We then employed Bayesian statistical analyses to generate expected catches for future target deployments incorporating uncertainty in model parameters, and prior knowledge from previous experiments. RESULTS Expected catches for average future replicates of violet and Vestergaard blue targets were highly likely to exceed those for typical blue. Accounting for catch variability between replicates, it remained moderately probable (70-86% and 59-84%, respectively) that a given replicate of these targets would have a higher expected catch than typical blue on the same day at the same site. Meanwhile, expected catches for average violet replicates were, in general, moderately likely to exceed those for Vestergaard blue. However, the difference in medians was small, and accounting for catch variability, the probability that the expected catch for a violet replicate would exceed a Vestergaard blue equivalent was marginal (46-71%). CONCLUSION Violet and Vestergaard ZeroFly blue are expected to outperform typical blue polyester in the Tiny Target configuration. Violet is unlikely to greatly outperform Vestergaard blue deployed in this way, but because violet is highly attractive to both riverine and savannah tsetse using different target designs, it may provide the more suitable general-purpose fabric.
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Affiliation(s)
- Roger D. Santer
- Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Michael N. Okal
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Steve J. Torr
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Bučanović T, Kovačević J, Krčmar S. Efficiency of six different octenol-baited traps for collecting horseflies (Diptera: Tabanidae). MEDICAL AND VETERINARY ENTOMOLOGY 2020; 34:493-497. [PMID: 32394541 DOI: 10.1111/mve.12447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/10/2020] [Accepted: 04/23/2020] [Indexed: 06/11/2023]
Abstract
The efficiency and the potential species preference for six different horsefly trap types was studied. A total of 2401 horseflies were collected during this study. The most effective trap was the modified box trap with (27.9%), followed by the Nzi trap with (24.5%), Malaise trap (Townes design 1972) with (22.5)%, canopy trap with (17.9%), modified small canopy trap with (7.0%) and Malaise trap (Townes design 1962) with (0.2%). The Nzi and Malaise trap (Townes design 1972) did not differ significantly in the number of collected horseflies. The comparison of all other traps revealed significant differences in the number of collected horseflies. Tabanus bromius was the most abundant species with (58.6%) of the collected sample. The modified box trap was the most successful in collecting of T. bromius, while the Malaise trap (Townes design 1972) was the most successful in collecting the species Haematopota pluvialis, T. maculicornis and T. tergestinus. This study demonstrated that different trap designs influenced the quantity, species and taxonomic diversity of horseflies that were collected. Variables in the trap design included cloth type and colour and size and shape of trap. More detailed studies should be done to determine which factor or factors are most significant.
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Affiliation(s)
- T Bučanović
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - J Kovačević
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - S Krčmar
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
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How MJ, Gonzales D, Irwin A, Caro T. Zebra stripes, tabanid biting flies and the aperture effect. Proc Biol Sci 2020; 287:20201521. [PMID: 32811316 PMCID: PMC7482270 DOI: 10.1098/rspb.2020.1521] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Of all hypotheses advanced for why zebras have stripes, avoidance of biting fly attack receives by far the most support, yet the mechanisms by which stripes thwart landings are not yet understood. A logical and popular hypothesis is that stripes interfere with optic flow patterns needed by flying insects to execute controlled landings. This could occur through disrupting the radial symmetry of optic flow via the aperture effect (i.e. generation of false motion cues by straight edges), or through spatio-temporal aliasing (i.e. misregistration of repeated features) of evenly spaced stripes. By recording and reconstructing tabanid fly behaviour around horses wearing differently patterned rugs, we could tease out these hypotheses using realistic target stimuli. We found that flies avoided landing on, flew faster near, and did not approach as close to striped and checked rugs compared to grey. Our observations that flies avoided checked patterns in a similar way to stripes refutes the hypothesis that stripes disrupt optic flow via the aperture effect, which critically demands parallel striped patterns. Our data narrow the menu of fly-equid visual interactions that form the basis for the extraordinary colouration of zebras.
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Affiliation(s)
- Martin J How
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Dunia Gonzales
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Alison Irwin
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Tim Caro
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.,Center for Population Biology, University of California, Davis, CA 95616, USA
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12
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Horváth G, Pereszlényi Á, Egri Á, Fritz B, Guttmann M, Lemmer U, Gomard G, Kriska G. Horsefly reactions to black surfaces: attractiveness to male and female tabanids versus surface tilt angle and temperature. Parasitol Res 2020; 119:2399-2409. [PMID: 32424552 PMCID: PMC7366589 DOI: 10.1007/s00436-020-06702-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/28/2020] [Indexed: 12/01/2022]
Abstract
Tabanid flies (Diptera: Tabanidae) are attracted to shiny black targets, prefer warmer hosts against colder ones and generally attack them in sunshine. Horizontally polarised light reflected from surfaces means water for water-seeking male and female tabanids. A shiny black target above the ground, reflecting light with high degrees and various directions of linear polarisation is recognised as a host animal by female tabanids seeking for blood. Since the body of host animals has differently oriented surface parts, the following question arises: How does the attractiveness of a tilted shiny black surface to male and female tabanids depend on the tilt angle δ? Another question relates to the reaction of horseflies to horizontal black test surfaces with respect to their surface temperature. Solar panels, for example, can induce horizontally polarised light and can reach temperatures above 55 °C. How long times would horseflies stay on such hot solar panels? The answer of these questions is important not only in tabanid control, but also in the reduction of polarised light pollution caused by solar panels. To study these questions, we performed field experiments in Hungary in the summer of 2019 with horseflies and black sticky and dry test surfaces. We found that the total number of trapped (male and female) tabanids is highest if the surface is horizontal (δ = 0°), and it is minimal at δ = 75°. The number of trapped males decreases monotonously to zero with increasing δ, while the female catch has a primary maximum and minimum at δ = 0° and δ = 75°, respectively, and a further secondary peak at δ = 90°. Both sexes are strongly attracted to nearly horizontal (0° ≤ δ ≤ 15°) surfaces, and the vertical surface is also very attractive but only for females. The numbers of touchdowns and landings of tabanids are practically independent of the surface temperature T. The time period of tabanids spent on the shiny black horizontal surface decreases with increasing T so that above 58 °C tabanids spent no longer than 1 s on the surface. The horizontally polarised light reflected from solar panels attracts aquatic insects. This attraction is adverse, if the lured insects lay their eggs onto the black surface and/or cannot escape from the polarised signal and perish due to dehydration. Using polarotactic horseflies as indicator insects in our field experiment, we determined the magnitude of polarised light pollution (being proportional to the visual attractiveness to tabanids) of smooth black oblique surfaces as functions of δ and T.
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Affiliation(s)
- Gábor Horváth
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117 Hungary
| | - Ádám Pereszlényi
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117 Hungary
- Department of Zoology, Hungarian Natural History Museum, Ludovika tér 2-6, Budapest, H-1083 Hungary
| | - Ádám Egri
- MTA Centre for Ecological Research, Danube Research Institute, Karolina út 29-31, Budapest, H-1113 Hungary
- MTA Centre for Ecological Research, Evolutionary Systems Research Group, Klebelsberg Kuno utca 3, Tihany, H-8237 Hungary
| | - Benjamin Fritz
- Light Technology Institute, Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, D-76131 Karlsruhe, Germany
| | - Markus Guttmann
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, D-76344 Karlsruhe, Germany
| | - Uli Lemmer
- Light Technology Institute, Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, D-76131 Karlsruhe, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, D-76344 Karlsruhe, Germany
| | - Guillaume Gomard
- Light Technology Institute, Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, D-76131 Karlsruhe, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, D-76344 Karlsruhe, Germany
| | - György Kriska
- MTA Centre for Ecological Research, Danube Research Institute, Karolina út 29-31, Budapest, H-1113 Hungary
- Group for Methodology in Biology Teaching, Biological Institute, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117 Hungary
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Why do biting horseflies prefer warmer hosts? tabanids can escape easier from warmer targets. PLoS One 2020; 15:e0233038. [PMID: 32401816 PMCID: PMC7219777 DOI: 10.1371/journal.pone.0233038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/26/2020] [Indexed: 11/21/2022] Open
Abstract
Blood-sucking horseflies (tabanids) prefer warmer (sunlit, darker) host animals and generally attack them in sunshine, the reason for which was unknown until now. Recently, it was hypothesized that blood-seeking female tabanids prefer elevated temperatures, because their wing muscles are quicker and their nervous system functions better at a warmer body temperature brought about by warmer microclimate, and thus they can more successfully avoid the host’s parasite-repelling reactions by prompt takeoffs. To test this hypothesis, we studied in field experiments the success rate of escape reactions of tabanids that landed on black targets as a function of the target temperature, and measured the surface temperature of differently coloured horses with thermography. We found that the escape success of tabanids decreased with decreasing target temperature, that is escape success is driven by temperature. Our results explain the behaviour of biting horseflies that they prefer warmer hosts against colder ones. Since in sunshine the darker the host the warmer its body surface, our results also explain why horseflies prefer sunlit dark (brown, black) hosts against bright (beige, white) ones, and why these parasites attack their hosts usually in sunshine, rather than under shaded conditions.
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Meglič A, Ilić M, Pirih P, Škorjanc A, Wehling MF, Kreft M, Belušič G. Horsefly object-directed polarotaxis is mediated by a stochastically distributed ommatidial subtype in the ventral retina. Proc Natl Acad Sci U S A 2019; 116:21843-21853. [PMID: 31591223 PMCID: PMC6815168 DOI: 10.1073/pnas.1910807116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The ventral compound eye of many insects contains polarization-sensitive photoreceptors, but little is known about how they are integrated into visual functions. In female horseflies, polarized reflections from animal fur are a key stimulus for host detection. To understand how polarization vision is mediated by the ventral compound eye, we investigated the band-eyed brown horsefly Tabanus bromius using anatomical, physiological, and behavioral approaches. Serial electron microscopic sectioning of the retina and single-cell recordings were used to determine the spectral and polarization sensitivity (PS) of photoreceptors. We found 2 stochastically distributed subtypes of ommatidia, analogous to pale and yellow of other flies. Importantly, the pale analog contains an orthogonal analyzer receptor pair with high PS, formed by an ultraviolet (UV)-sensitive R7 and a UV- and blue-sensitive R8, while the UV-sensitive R7 and green-sensitive R8 in the yellow analog always have low PS. We tested horsefly polarotaxis in the field, using lures with controlled spectral and polarization composition. Polarized reflections without UV and blue components rendered the lures unattractive, while reflections without the green component increased their attractiveness. This is consistent with polarotaxis being guided by a differential signal from polarization analyzers in the pale analogs, and with an inhibitory role of the yellow analogs. Our results reveal how stochastically distributed sensory units with modality-specific division of labor serve as separate and opposing input channels for visual guidance.
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Affiliation(s)
- Andrej Meglič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Marko Ilić
- Laboratory of Neuroethology, Sokendai - The Graduate University for Advanced Studies, 240-0193 Hayama, Japan
| | - Primož Pirih
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Aleš Škorjanc
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Martin F Wehling
- Nature-inspired Team, Sensor and Imaging Sciences Branch, Air Force Research Laboratory, Eglin Air Force Base, FL 32542
| | - Marko Kreft
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
- Celica Biomedical, 1000 Ljubljana, Slovenia
| | - Gregor Belušič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia;
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Kojima T, Oishi K, Matsubara Y, Uchiyama Y, Fukushima Y, Aoki N, Sato S, Masuda T, Ueda J, Hirooka H, Kino K. Cows painted with zebra-like striping can avoid biting fly attack. PLoS One 2019; 14:e0223447. [PMID: 31581218 PMCID: PMC6776349 DOI: 10.1371/journal.pone.0223447] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/20/2019] [Indexed: 11/19/2022] Open
Abstract
Experimental and comparative studies suggest that the striped coats of zebras can prevent biting fly attacks. Biting flies are serious pests of livestock that cause economic losses in animal production. We hypothesized that cows painted with black and white stripes on their body could avoid biting fly attacks and show fewer fly-repelling behaviors. Six Japanese Black cows were assigned to treatments using a 3 × 3 Latin-square design. The treatments were black-and-white painted stripes, black painted stripes, and no stripes (all-black body surface). Recorded fly-repelling behaviors were head throw, ear beat, leg stamp, skin twitch, and tail flick. Photo images of the right side of each cow were taken using a commercial digital camera after every observation and biting flies on the body and each leg were counted from the photo images. Here we show that the numbers of biting flies on Japanese Black cows painted with black-and-white stripes were significantly lower than those on non-painted cows and cows painted only with black stripes. The frequencies of fly-repelling behaviors in cows painted with black-and-white stripes were also lower than those in the non-painted and black-striped cows. These results thus suggest that painting black-and-white stripes on livestock such as cattle can prevent biting fly attacks and provide an alternative method of defending livestock against biting flies without using pesticides in animal production, thereby proposing a solution for the problem of pesticide resistance in the environment.
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Affiliation(s)
- Tomoki Kojima
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
- * E-mail:
| | - Kazato Oishi
- Laboratory of Animal Husbandry Resources, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yasushi Matsubara
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
| | - Yuki Uchiyama
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
| | - Yoshihiko Fukushima
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
| | - Naoto Aoki
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
| | - Say Sato
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
| | - Tatsuaki Masuda
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
| | - Junichi Ueda
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
- Aichi Veterinary Association, Nagoya, Aichi, Japan
| | - Hiroyuki Hirooka
- Laboratory of Animal Husbandry Resources, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Katsutoshi Kino
- Animal Husbandry Division, Aichi Agricultural Research Center, Nagakute, Aichi, Japan
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Horváth G, Pereszlényi Á, Tóth T, Polgár S, Jánosi IM. Attractiveness of thermally different, uniformly black targets to horseflies: Tabanus tergestinus prefers sunlit warm shiny dark targets. ROYAL SOCIETY OPEN SCIENCE 2019; 6:191119. [PMID: 31824718 PMCID: PMC6837212 DOI: 10.1098/rsos.191119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/23/2019] [Indexed: 06/10/2023]
Abstract
From a large distance tabanid flies may find their host animal by means of its shape, size, motion, odour, radiance and degree of polarization of host-reflected light. After alighting on the host, tabanids may use their mechano-, thermo-, hygro- and chemoreceptors to sense the substrate characteristics. Female tabanids prefer to attack sunlit against shady dark host animals, or dark against bright hosts for a blood meal, the exact reasons for which are unknown. Since sunlit darker surfaces are warmer than shady ones or sunlit/shady brighter surfaces, the differences in surface temperatures of dark and bright as well as sunlit and shady hosts may partly explain their different attractiveness to tabanids. We tested this observed warmth preference in field experiments, where we compared the attractiveness to tabanids (Tabanus tergestinus) of a warm and a cold shiny black barrel imitating dark hosts with the same optical characteristics. Using imaging polarimetry, thermography and Schlieren imaging, we measured the optical and thermal characteristics of both barrels and their small-scale models. We recorded the number of landings on these targets and measured the time periods spent on them. Our study revealed that T. tergestinus tabanid flies prefer sunlit warm shiny black targets against sunlit or shady cold ones with the same optical characteristics. These results support our new hypothesis that a blood-seeking female tabanid prefers elevated temperatures, partly because her wing muscles are more rapid and her nervous system functions better (due to faster conduction velocities and synaptic transmission of signals) in a warmer microclimate, and thus, she can avoid the parasite-repelling reactions of host animals by a prompt take-off.
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Affiliation(s)
- Gábor Horváth
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - Ádám Pereszlényi
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
- Hungarian Natural History Museum, Department of Zoology, Bird Collection, 1083 Budapest, Ludovika tér 2-6, Hungary
| | - Tímea Tóth
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - Szabolcs Polgár
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - Imre M. Jánosi
- Department of Physics of Complex Systems, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
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Horváth G, Pereszlényi Á, Åkesson S, Kriska G. Striped bodypainting protects against horseflies. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181325. [PMID: 30800379 PMCID: PMC6366178 DOI: 10.1098/rsos.181325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 12/11/2018] [Indexed: 06/09/2023]
Abstract
Bodypainting is widespread in African, Australian and Papua New Guinean indigenous communities. Many bodypaintings use white or bright yellow/grey/beige stripes on brown skin. Where the majority of people using bodypainting presently live, blood-sucking horseflies are abundant, and they frequently attack the naked brown regions of the human body surface with the risk of transmitting the pathogens of dangerous diseases. Since horseflies are deterred by the black and white stripes of zebras, we hypothesized that white-striped paintings on dark brown human bodies have a similar effect. In a field experiment in Hungary, we tested this hypothesis. We show that the attractiveness to horseflies of a dark brown human body model significantly decreases, if it is painted with the white stripes that are used in bodypaintings. Our brown human model was 10 times more attractive to horseflies than the white-striped brown model, and a beige model, which was used as a control, attracted two times more horseflies than the striped brown model. Thus, white-striped bodypaintings, such as those used by African and Australian people, may serve to deter horseflies, which is an advantageous byproduct of these bodypaintings that could lead to reduced irritation and disease transmission by these blood-sucking insects.
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Affiliation(s)
- Gábor Horváth
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - Ádám Pereszlényi
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
- Hungarian Natural History Museum, Department of Zoology, Bird Collection, 1083 Budapest, Ludovika tér 2-6, Hungary
| | - Susanne Åkesson
- Department of Biology, Centre for Animal Movement Research, Lund University, Ecology Building, 223 62 Lund, Sweden
| | - György Kriska
- MTA Centre for Ecological Research, Danube Research Institute, 1113 Budapest, Karolina út 29-31, Hungary
- Biological Institute, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
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Standardising visual control devices for Tsetse: East and Central African Savannah species Glossina swynnertoni, Glossina morsitans centralis and Glossina pallidipes. PLoS Negl Trop Dis 2018; 12:e0006831. [PMID: 30252848 PMCID: PMC6173441 DOI: 10.1371/journal.pntd.0006831] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 10/05/2018] [Accepted: 09/11/2018] [Indexed: 11/19/2022] Open
Abstract
Background This study focused on the savannah tsetse species Glossina swynnertoni and G. morsitans centralis, both efficient vectors of human and animal trypanosomiasis in, respectively, East and Central Africa. The aim was to develop long-lasting, practical and cost-effective visually attractive devices that induce the strongest landing responses in these two species for use as insecticide-impregnated tools in population suppression. Methods and findings Trials were conducted in different seasons and years in Tanzania (G. swynnertoni) and in Angola and the Democratic Republic of the Congo (DRC, G. m. centralis) to measure the performance of traps (pyramidal and epsilon) and targets of different sizes, shapes and colours, with and without chemical baits, at different population densities and under different environmental conditions. Adhesive film was used to catch flies landing on devices at the remote locations to compare tsetse-landing efficiencies. Landing rates by G. m. centralis in both Angola and the DRC were highest on blue-black 1 m2 oblong and 0.5 m2 square and oblong targets but were not significantly different from landings on the pyramidal trap. Landings by G. swynnertoni on 0.5 m2 blue-black oblong targets were likewise not significantly lower than on equivalent 1 m2 square targets. The length of target horizontal edge was closely correlated with landing rate. Blue-black 0.5 m2 targets performed better than equivalents in all-blue for both G. swynnertoni and G. m. centralis, although not consistently. Baiting with chemicals increased the proportion of G. m. centralis entering pyramidal traps. Conclusions This study confirms earlier findings on G. swynnertoni that smaller visual targets, down to 0.5 m2, would be as efficient as using 1 m2 targets for population management of this species. This is also the case for G. m. centralis. An insecticide-impregnated pyramidal trap would also constitute an effective control device for G. m. centralis. Glossina swynnertoni is restricted to open savannah in northwestern Tanzania and southwestern Kenya whereas G. morsitans centralis has a much wider distribution from western Tanzania/southern Uganda westwards through Zambia and southeast of the Democratic Republic of the Congo (DRC) to Angola. Both are savannah tsetse and are efficient vectors of human and animal trypanosomiasis. In comparison to other tsetse species, relatively little work has been done to test the efficacy of traps and targets for controlling G. swynnertoni and G. m. centralis. To determine the most visually-attractive and practical objects we conducted field tests with devices of various shapes, sizes and colours in Tanzania, DRC and Angola in different years, seasons, environmental conditions and at different population densities. The strongest landing responses were on 0.5 m2 horizontal rectangular targets with respect to ground that had both black and phthalogen blue elements with fly landing rates not significantly lower than on equivalent 1 m2 targets used till now for both species. The pyramidal trap proved efficient as a landing stimulus as targets of either size for G. m. centralis. Insecticide-impregnated blue-black 0.5 m2 cloth targets show promise as cost-effective devices for management of G. swynnertoni and G. m. centralis populations.
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