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Reynolds AM. Mosquito swarms shear harden. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:126. [PMID: 38063901 PMCID: PMC10709253 DOI: 10.1140/epje/s10189-023-00379-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/15/2023] [Indexed: 12/18/2023]
Abstract
Recently Cavagna et al. (Sci Rep 13(1): 8745, 2023) documented the swarming behaviors of laboratory-based Anopheles gambiae mosquitoes. Here key observations from this 3D-video tracking study are reproduced by a minimally structured (maximum entropy) stochastic trajectory model. The modelling shows that in contrast with midge swarms which are a form of collective behavior, unperturbed mosquito swarms are more like collections of individuals that independently circulate around a fixed location. The modelling predicts the observed response Anopheles gambiae mosquitoes in wild swarms to varying wind speeds (Butail et al. in J Med Entomol 50(3): 552-559, 2013). It is shown that this response can be attributed to shear hardening. This is because mosquitoes are found to be attracted to the centre of the swarm by an effective force that increases with increasing flight speed. Mosquitoes can therefore better resist the influence of environmental disturbances by increasing their flight speeds. This contrasts with other emergent mechanical-like properties of swarming which arise accidentally without a change in an individual's behavior. The new results add to the growing realization that perturbations can drive swarms into more robust states.
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Wassmer T, Armstrong E. Population structure of Phanaeus vindex (Coleoptera: Scarabaeidae) in SE Michigan. JOURNAL OF INSECT SCIENCE (ONLINE) 2023; 23:2. [PMID: 37399115 DOI: 10.1093/jisesa/iead050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/27/2023] [Accepted: 06/13/2023] [Indexed: 07/05/2023]
Abstract
Until now, little is known about the population structure and mobility of temperate dung beetles including the rainbow scarab, Phanaeus vindex (MacLeay 1819), although this knowledge is essential for their conservation as pastures become increasingly rare and the landscape fragmented by monocultures and urbanization. Here, we estimated population size, longevity, and dispersal within and between pastures. For 3 yr, we life-trapped beetles every week on 2 adjacent farms in SE Michigan, determined their sex, male morph, and size, and marked their elytra with individual tattoo patterns before releasing them. We marked a total of 470 rainbow scarabs of which 14 were recaptured once and 2 were recaptured twice. The sex ratio was not significantly sex-biased but fluctuated between months with no apparent uniformity between years. While the minor to major male ratios were unbiased in 2019 and 2020, they were marginally minor-biased in 2021. The gross population estimates for the 2 farms were 458-491 and 217 rainbow scarabs, respectively. Beetles traveled distances of up to 178 m within farms. No beetles dispersed between farms. One large female was recaptured after 338 days documenting the first cold hardiness and long lifespan of a cold-temperate dung beetle species in the wild. The low population estimates on both farms indicate 2 vulnerable populations with no or extremely limited connectivity. Supplementary funding for the land stewardship of small-scale cattle farmers could stabilize populations of native dung beetles and maintain their ecosystem services.
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Affiliation(s)
- Thomas Wassmer
- Department of Biology, Siena Heights University, 1247 E. Siena Heights Drive, Adrian, MI 49221, USA
| | - Elise Armstrong
- Department of Biology, Siena Heights University, 1247 E. Siena Heights Drive, Adrian, MI 49221, USA
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Kohl PL, Rutschmann B, Sikora LG, Wimmer N, Zahner V, D'Alvise P, Hasselmann M, Steffan-Dewenter I. Parasites, depredators, and limited resources as potential drivers of winter mortality of feral honeybee colonies in German forests. Oecologia 2023:10.1007/s00442-023-05399-6. [PMID: 37365409 PMCID: PMC10386939 DOI: 10.1007/s00442-023-05399-6] [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: 02/28/2023] [Accepted: 06/02/2023] [Indexed: 06/28/2023]
Abstract
Wild honeybees (Apis mellifera) are considered extinct in most parts of Europe. The likely causes of their decline include increased parasite burden, lack of high-quality nesting sites and associated depredation pressure, and food scarcity. In Germany, feral honeybees still colonize managed forests, but their survival rate is too low to maintain viable populations. Based on colony observations collected during a monitoring study, data on parasite prevalence, experiments on nest depredation, and analyses of land cover maps, we explored whether parasite pressure, depredation or expected landscape-level food availability explain feral colony winter mortality. Considering the colony-level occurrence of 18 microparasites in the previous summer, colonies that died did not have a higher parasite burden than colonies that survived. Camera traps installed at cavity trees revealed that four woodpecker species, great tits, and pine martens act as nest depredators. In a depredator exclusion experiment, the winter survival rate of colonies in cavities with protected entrances was 50% higher than that of colonies with unmanipulated entrances. Landscapes surrounding surviving colonies contained on average 6.4 percentage points more cropland than landscapes surrounding dying colonies, with cropland being known to disproportionately provide forage for bees in our study system. We conclude that the lack of spacious but well-protected nesting cavities and the shortage of food are currently more important than parasites in limiting populations of wild-living honeybees in German forests. Increasing the density and diversity of large tree cavities and promoting bee forage plants in forests will probably promote wild-living honeybees despite parasite pressure.
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Affiliation(s)
- Patrick L Kohl
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany.
| | - Benjamin Rutschmann
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany.
| | | | - Norbert Wimmer
- Bayerische Landesanstalt Für Wald Und Forstwirtschaft, Freising, Germany
| | - Volker Zahner
- Forest Ecology and Management, University of Applied Sciences Weihenstephan-Triesdorf, Freising, Germany
| | - Paul D'Alvise
- Department of Livestock Population Genomics, Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
- Institute for Medical Microbiology and Hygiene, University Hospital Tübingen, Tübingen, Germany
| | - Martin Hasselmann
- Department of Livestock Population Genomics, Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
| | - Ingolf Steffan-Dewenter
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
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Carcaud J, Otte M, Grünewald B, Haase A, Sandoz JC, Beye M. Multisite imaging of neural activity using a genetically encoded calcium sensor in the honey bee. PLoS Biol 2023; 21:e3001984. [PMID: 36719927 PMCID: PMC9917304 DOI: 10.1371/journal.pbio.3001984] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 02/10/2023] [Accepted: 01/03/2023] [Indexed: 02/01/2023] Open
Abstract
Understanding of the neural bases for complex behaviors in Hymenoptera insect species has been limited by a lack of tools that allow measuring neuronal activity simultaneously in different brain regions. Here, we developed the first pan-neuronal genetic driver in a Hymenopteran model organism, the honey bee, and expressed the calcium indicator GCaMP6f under the control of the honey bee synapsin promoter. We show that GCaMP6f is widely expressed in the honey bee brain, allowing to record neural activity from multiple brain regions. To assess the power of this tool, we focused on the olfactory system, recording simultaneous responses from the antennal lobe, and from the more poorly investigated lateral horn (LH) and mushroom body (MB) calyces. Neural responses to 16 distinct odorants demonstrate that odorant quality (chemical structure) and quantity are faithfully encoded in the honey bee antennal lobe. In contrast, odor coding in the LH departs from this simple physico-chemical coding, supporting the role of this structure in coding the biological value of odorants. We further demonstrate robust neural responses to several bee pheromone odorants, key drivers of social behavior, in the LH. Combined, these brain recordings represent the first use of a neurogenetic tool for recording large-scale neural activity in a eusocial insect and will be of utility in assessing the neural underpinnings of olfactory and other sensory modalities and of social behaviors and cognitive abilities.
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Affiliation(s)
- Julie Carcaud
- Evolution, Genomes, Behavior and Ecology, Université Paris-Saclay, CNRS, IRD, Gif-sur-Yvette, France
- * E-mail:
| | - Marianne Otte
- Evolutionnary Genetics, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Bernd Grünewald
- Institut für Bienenkunde, Polytechnische Gesellschaft, FB Biowissenschaften, Goethe-University, Frankfurt am Main, Germany
| | - Albrecht Haase
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
- Department of Physics, University of Trento, Trento, Italy
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, Université Paris-Saclay, CNRS, IRD, Gif-sur-Yvette, France
| | - Martin Beye
- Evolutionnary Genetics, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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Reynolds AM, McIvor GE, Thornton A, Yang P, Ouellette NT. Stochastic modelling of bird flocks: accounting for the cohesiveness of collective motion. J R Soc Interface 2022; 19:20210745. [PMID: 35440203 PMCID: PMC9019524 DOI: 10.1098/rsif.2021.0745] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Collective behaviour can be difficult to discern because it is not limited to animal aggregations such as flocks of birds and schools of fish wherein individuals spontaneously move in the same way despite the absence of leadership. Insect swarms are, for example, a form of collective behaviour, albeit one lacking the global order seen in bird flocks and fish schools. Their collective behaviour is evident in their emergent macroscopic properties. These properties are predicted by close relatives of Okubo's 1986 [Adv. Biophys. 22, 1-94. (doi:10.1016/0065-227X(86)90003-1)] stochastic model. Here, we argue that Okubo's stochastic model also encapsulates the cohesiveness mechanism at play in bird flocks, namely the fact that birds within a flock behave on average as if they are trapped in an elastic potential well. That is, each bird effectively behaves as if it is bound to the flock by a force that on average increases linearly as the distance from the flock centre increases. We uncover this key, but until now overlooked, feature of flocking in empirical data. This gives us a means of identifying what makes a given system collective. We show how the model can be extended to account for intrinsic velocity correlations and differentiated social relationships.
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Affiliation(s)
| | - Guillam E McIvor
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9FE, UK
| | - Alex Thornton
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9FE, UK
| | - Patricia Yang
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
| | - Nicholas T Ouellette
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
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Space, the original frontier. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hagadorn MA, Eck K, Del Grosso M, Haemmerle X, Wcislo WT, Kapheim KM. Age-related mushroom body expansion in male sweat bees and bumble bees. Sci Rep 2021; 11:17039. [PMID: 34426595 PMCID: PMC8382693 DOI: 10.1038/s41598-021-96268-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/04/2021] [Indexed: 01/20/2023] Open
Abstract
A well-documented phenomenon among social insects is that brain changes occur prior to or at the onset of certain experiences, potentially serving to prime the brain for specific tasks. This insight comes almost exclusively from studies considering developmental maturation in females. As a result, it is unclear whether age-related brain plasticity is consistent across sexes, and to what extent developmental patterns differ. Using confocal microscopy and volumetric analyses, we investigated age-related brain changes coinciding with sexual maturation in the males of the facultatively eusocial sweat bee, Megalopta genalis, and the obligately eusocial bumble bee, Bombus impatiens. We compared volumetric measurements between newly eclosed and reproductively mature males kept isolated in the lab. We found expansion of the mushroom bodies-brain regions associated with learning and memory-with maturation, which were consistent across both species. This age-related plasticity may, therefore, play a functionally-relevant role in preparing male bees for mating, and suggests that developmentally-driven neural restructuring can occur in males, even in species where it is absent in females.
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Affiliation(s)
- Mallory A Hagadorn
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT, 84322, USA.
| | - Karlee Eck
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT, 84322, USA
| | - Matthew Del Grosso
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT, 84322, USA
| | - Xavier Haemmerle
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT, 84322, USA
| | - William T Wcislo
- Smithsonian Tropical Research Institute, 0843-03092, Panama City, Republic of Panama
| | - Karen M Kapheim
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT, 84322, USA.
- Smithsonian Tropical Research Institute, 0843-03092, Panama City, Republic of Panama.
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Slater GP, Smith NMA, Harpur BA. Prospects in Connecting Genetic Variation to Variation in Fertility in Male Bees. Genes (Basel) 2021; 12:1251. [PMID: 34440424 PMCID: PMC8392204 DOI: 10.3390/genes12081251] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/13/2021] [Accepted: 08/14/2021] [Indexed: 12/20/2022] Open
Abstract
Bees are economically and ecologically important pollinating species. Managed and native bee species face increasing pressures from human-created stressors such as habitat loss, pesticide use, and introduced pathogens. There has been increasing attention towards how each of these factors impacts fertility, especially sperm production and maintenance in males. Here, we turn our attention towards another important factor impacting phenotypic variation: genetics. Using honey bees as a model, we explore the current understanding of how genetic variation within and between populations contributes to variation in sperm production, sperm maintenance, and insemination success among males. We conclude with perspectives and future directions in the study of male fertility in honey bees and non-Apis pollinators more broadly, which still remain largely understudied.
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Affiliation(s)
- Garett P. Slater
- Department of Entomology, Purdue University, 901 W State St., West Lafayette, IN 47907, USA;
| | - Nicholas M. A. Smith
- School of Biological Sciences, The University of Queensland, Saint Lucia, QLD 4072, Australia;
| | - Brock A. Harpur
- Department of Entomology, Purdue University, 901 W State St., West Lafayette, IN 47907, USA;
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