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Svoboda J, Pech P, Heneberg P. Low concentrations of acetamiprid, deltamethrin, and sulfoxaflor, three commonly used insecticides, adversely affect ant queen survival and egg laying. Sci Rep 2023; 13:14893. [PMID: 37689830 PMCID: PMC10492783 DOI: 10.1038/s41598-023-42129-7] [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: 04/22/2023] [Accepted: 09/05/2023] [Indexed: 09/11/2023] Open
Abstract
Ants are key ecosystem service providers and can serve as important biological control agents in pest management. However, the effects of insecticides on common farmland ant species are poorly understood. We tested the effects of three commonly used insecticides on ants (Hymenoptera, Formicidae). The tested insecticides were acetamiprid (neonicotinoid; formulated as Mospilan 20 SP), deltamethrin (pyrethroid; formulated as Sanium Ultra), and sulfoxaflor (sulfilimine; formulated as Gondola). We tested two ant (Hymenoptera: Formicidae) species with different colony founding strategies, Lasius niger (Linnaeus, 1758) and Myrmica rubra (Linnaeus, 1758). We sprayed their queens with insecticides at concentrations recommended for use in foliar applications in agriculture, i.e., at 1.25 g L-1 (acetamiprid), 0.6 g L-1 (sulfoxaflor), and 0.875 g L-1 (deltamethrin). Further, we diluted the compounds in distilled water and tested them at 10%, 1%, and 0.1% of the field-recommended concentrations, and used distilled water as a control. We monitored the survival of the queens and the number of eggs laid. All three tested insecticides caused severe lethal and sublethal concentration-dependent effects. Even at concentrations three orders of magnitudes lower than recommended for field applications, significantly lower numbers of eggs were found in the queens' nests. The extent of the sublethal effects of acetamiprid and sulfoxaflor was concentration-dependent and differed between the two ant species. Besides bees and bumblebees, ants represent an important group of hymenopterans that are severely affected even by low concentrations of the tested compounds and therefore should be included in risk assessment schemes.
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Affiliation(s)
- Jakub Svoboda
- Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Pavel Pech
- Research and Breeding Institute of Pomology Holovousy Ltd., 508 01, Holovousy 129, Czech Republic
| | - Petr Heneberg
- Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Prague, Czech Republic.
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2
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Collins DH, Prince DC, Donelan JL, Chapman T, Bourke AFG. Costs of reproduction are present but latent in eusocial bumblebee queens. BMC Biol 2023; 21:153. [PMID: 37430246 DOI: 10.1186/s12915-023-01648-5] [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: 08/25/2022] [Accepted: 06/12/2023] [Indexed: 07/12/2023] Open
Abstract
BACKGROUND The standard evolutionary theory of ageing proposes that ageing occurs because of a trade-off between reproduction and longevity. Eusocial insect queens exhibit positive fecundity-longevity associations and so have been suggested to be counter-examples through not expressing costs of reproduction and through remodelling conserved genetic and endocrine networks regulating ageing and reproduction. If so, eusocial evolution from solitary ancestors with negative fecundity-longevity associations must have involved a stage at which costs of reproduction were suppressed and fecundity and longevity became positively associated. Using the bumblebee (Bombus terrestris), we experimentally tested whether queens in annual eusocial insects at an intermediate level of eusocial complexity experience costs of reproduction, and, using mRNA-seq, the extent to which they exhibit a remodelling of relevant genetic and endocrine networks. Specifically, we tested whether costs of reproduction are present but latent, or whether a remodelling of relevant genetic and endocrine networks has already occurred allowing queens to reproduce without costs. RESULTS We experimentally increased queens' costs of reproduction by removing their eggs, which caused queens to increase their egg-laying rate. Treatment queens had significantly reduced longevity relative to control queens whose egg-laying rate was not increased. Reduced longevity in treatment queens was not caused by increased worker-to-queen aggression or by increased overall activity in queens. In addition, treatment and control queens differed in age-related gene expression based on mRNA-seq in both their overall expression profiles and the expression of ageing-related genes. Remarkably, these differences appeared to occur principally with respect to relative age, not chronological age. CONCLUSIONS This study represents the first simultaneously phenotypic and transcriptomic experimental test for a longevity cost of reproduction in eusocial insect queens. The results support the occurrence of costs of reproduction in annual eusocial insects of intermediate social complexity and suggest that reproductive costs are present but latent in queens of such species, i.e. that these queens exhibit condition-dependent positive fecundity-longevity associations. They also raise the possibility that a partial remodelling of genetic and endocrine networks underpinning ageing may have occurred in intermediately eusocial species such that, in unmanipulated conditions, age-related gene expression depends more on chronological than relative age.
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Affiliation(s)
- David H Collins
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - David C Prince
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Jenny L Donelan
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Andrew F G Bourke
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
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3
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Price TN, Field J. Sisters doing it for themselves: extensive reproductive plasticity in workers of a primitively eusocial bee. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03196-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Abstract
Plasticity is a key trait when an individual’s role in the social environment, and hence its optimum phenotype, fluctuates unpredictably. Plasticity is especially important in primitively eusocial insects where small colony sizes and little morphological caste differentiation mean that individuals may find themselves switching from non-reproductive to reproductive roles. To understand the scope of this plasticity, workers of the primitively eusocial sweat bee Lasioglossum malachurum were experimentally promoted to the reproductive role (worker-queens) and their performance compared with foundress-queens. We focussed on how their developmental trajectory as workers influenced three key traits: group productivity, monopolisation of reproduction, and social control of foraging nest-mates. No significant difference was found between the number of offspring produced by worker-queens and foundress-queens. Genotyping of larvae showed that worker-queens monopolised reproduction in their nests to the same extent as foundress queens. However, non-reproductives foraged less and produced a smaller total offspring biomass when the reproductive was a promoted worker: offspring of worker-queens were all males, which are the cheaper sex to produce. Greater investment in each offspring as the number of foragers increased suggests a limit to both worker-queen and foundress-queen offspring production when a greater quantity of pollen arrives at the nest. The data presented here suggest a remarkable level of plasticity and represent one of the first quantitative studies of worker reproductive plasticity in a non-model primitively eusocial species.
Significance statement
The ability of workers to take on a reproductive role and produce offspring is expected to relate strongly to the size of their colony. Workers in species with smaller colony sizes should have greater reproductive potential to insure against the death of the queen. We quantified the reproductive plasticity of workers in small colonies of sweat bees by removing the queen and allowing the workers to control the reproductive output of the nest. A single worker then took on the reproductive role and hence prevented her fellow workers from producing offspring of their own. These worker-queens produced as many offspring as control queens, demonstrating remarkable worker plasticity in a primitively eusocial species.
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Di Pietro V, Ferreira HM, Van Oystaeyen A, Wäckers F, Wenseleers T, Oliveira RC. Distinct Colony Types Caused by Diploid Male Production in the Buff-Tailed Bumblebee Bombus terrestris. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.844251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The buff-tailed bumblebee Bombus terrestris presents two distinct colony phenotypes in which some colonies already start producing males very early in the season, while others switch to producing sexuals much later in the season, and specialize mainly in the production of virgin queens. Despite having been extensively investigated in the past, the mechanisms underlying these two distinct phenotypes remain poorly understood. Here we use a combination of behavioral and genetic data to demonstrate that early switchers are in fact diploid male producing colonies, while late switchers produced normal, haploid males. Hence, at a proximate level, early switching to male production was caused by queens mating with males that by chance carried the same sex allele. These patterns were not the result of strong inbreeding within the study population, as the average inbreeding coefficient was very low and in fact slightly negative (−0.11). Moreover, an effect of inbreeding was further excluded because hybrids produced by crossing two distinct outbred populations also produced diploid males in early switching colonies. Finally, we found that diploid males only emerged after a first cohort of workers was produced, while we would have expected diploid males to be produced simultaneously with workers in a 50:50 ratio. We demonstrate that adult diploid males had a distinct cuticular hydrocarbon profile and propose that queens likely cull diploid males during early colony development to reduce the cost of diploid male production.
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Beani L, Dallai R, Cappa F, Manfredini F, Zaccaroni M, Lorenzi MC, Mercati D. A Stresipteran parasite extends the lifespan of workers in a social wasp. Sci Rep 2021; 11:7235. [PMID: 33790321 PMCID: PMC8012566 DOI: 10.1038/s41598-021-86182-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
In social wasps, female lifespan depends on caste and colony tasks: workers usually live a few weeks while queens as long as 1 year. Polistes dominula paper wasps infected by the strepsipteran parasite Xenos vesparum avoid all colony tasks, cluster on vegetation where parasite dispersal and mating occur, hibernate and infect the next generation of wasp larvae. Here, we compared the survival rate of infected and uninfected wasp workers. Workers' survival was significantly affected by parasite sex: two-third of workers parasitized by a X. vesparum female survived and overwintered like future queens did, while all workers infected by a X. vesparum male died during the summer, like uninfected workers that we used as controls. We measured a set of host and parasite traits possibly associated with the observed lifespan extension. Infected overwintering workers had larger fat bodies than infected workers that died in the summer, but they had similar body size and ovary development. Furthermore, we recorded a positive correlation between parasite and host body sizes. We hypothesize that the manipulation of worker's longevity operated by X. vesparum enhances parasite's fitness: if workers infected by a female overwinter, they can spread infective parasite larvae in the spring like parasitized gynes do, thus contributing to parasite transmission.
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Affiliation(s)
- Laura Beani
- Dipartimento di Biologia, Università di Firenze, Via Madonna del piano 6, 50019, Sesto Fiorentino, Florence, Italy.
| | - Romano Dallai
- Dipartimento di Scienze Della Vita, Università di Siena, Via Aldo Moro, 53100, Siena, Italy
| | - Federico Cappa
- Dipartimento di Biologia, Università di Firenze, Via Madonna del piano 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Fabio Manfredini
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Marco Zaccaroni
- Dipartimento di Biologia, Università di Firenze, Via Madonna del piano 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Maria Cristina Lorenzi
- LEEC, Laboratoire d'Éthologie Expérimentale et Comparée, Université Sorbonne Paris Nord, Villetaneuse, France
| | - David Mercati
- Dipartimento di Scienze Della Vita, Università di Siena, Via Aldo Moro, 53100, Siena, Italy
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Raines KE, Whitehorn PR, Copplestone D, Tinsley MC. Chernobyl-level radiation exposure damages bumblebee reproduction: a laboratory experiment. Proc Biol Sci 2020; 287:20201638. [PMID: 33081610 PMCID: PMC7661291 DOI: 10.1098/rspb.2020.1638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/30/2020] [Indexed: 12/16/2022] Open
Abstract
The consequences for wildlife of living in radiologically contaminated environments are uncertain. Previous laboratory studies suggest insects are relatively radiation-resistant; however, some field studies from the Chernobyl Exclusion Zone report severe adverse effects at substantially lower radiation dose rates than expected. Here, we present the first laboratory investigation to study how environmentally relevant radiation exposure affects bumblebee life history, assessing the shape of the relationship between radiation exposure and fitness loss. Dose rates comparable to the Chernobyl Exclusion Zone (50-400 µGy h-1) impaired bumblebee reproduction and delayed colony growth but did not affect colony weight or longevity. Our best-fitting model for the effect of radiation dose rate on colony queen production had a strongly nonlinear concave relationship: exposure to only 100 µGy h-1 impaired reproduction by 30-45%, while further dose rate increases caused more modest additional reproductive impairment. Our data indicate that the practice of estimating effects of environmentally relevant low-dose rate exposure by extrapolating from high-dose rates may have considerably underestimated the effects of radiation. If our data can be generalized, they suggest insects suffer significant negative consequences at dose rates previously thought safe; we therefore advocate relevant revisions to the international framework for radiological protection of the environment.
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Affiliation(s)
| | - Penelope R. Whitehorn
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research Atmospheric Environmental Research (IMK-IFU), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany
| | - David Copplestone
- Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
| | - Matthew C. Tinsley
- Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
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Koubová J, Jehlík T, Kodrík D, Sábová M, Šima P, Sehadová H, Závodská R, Frydrychová RČ. Telomerase activity is upregulated in the fat bodies of pre-diapause bumblebee queens (Bombus terrestris). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 115:103241. [PMID: 31536769 DOI: 10.1016/j.ibmb.2019.103241] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
The attrition of telomeres, the ends of eukaryote chromosomes, and activity of telomerase, the enzyme that restores telomere length, play a role in the ageing process and act as indicators of biological age. A notable feature of advanced eusocial insects is the longevity of reproductive individuals (queens and kings) compared to those from non-reproductive castes (workers and soldiers) within a given species, with a proposed link towards upregulation of telomerase activity in the somatic tissues of reproductive individuals. Given this, eusocial insects provide excellent model systems for research into ageing. We tested telomerase activity and measured telomere length in Bombus terrestris, which is a primitively eusocial insect species with several distinct features compared to advanced social insects. In somatic tissues, telomerase activity was upregulated only in the fat bodies of pre-diapause queens, and this upregulation was linked to heightened DNA synthesis. Telomere length was shorter in old queens compared to that in younger queens or workers. We speculate that (1) the upregulation of telomerase activity, together with DNA synthesis, is the essential step for intensifying metabolic activity in the fat body to build up a sufficient energy reserve prior to diapause, and that (2) the lifespan differences between B. terrestris workers and queens are related to the long diapause period of the queen. A possible relationship between telomere length regulation and TOR, FOXO, and InR as cell signaling components, was tested.
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Affiliation(s)
- Justina Koubová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Tomáš Jehlík
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Dalibor Kodrík
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Michala Sábová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Peter Šima
- Koppert s.r.o., Komárňanská cesta 13, 940 01, Nové Zámky, Slovakia
| | - Hana Sehadová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Radka Závodská
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Pedagogy, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Radmila Čapková Frydrychová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic.
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8
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Johnson AA, Shokhirev MN, Shoshitaishvili B. Revamping the evolutionary theories of aging. Ageing Res Rev 2019; 55:100947. [PMID: 31449890 DOI: 10.1016/j.arr.2019.100947] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 07/20/2019] [Accepted: 08/21/2019] [Indexed: 01/04/2023]
Abstract
Radical lifespan disparities exist in the animal kingdom. While the ocean quahog can survive for half a millennium, the mayfly survives for less than 48 h. The evolutionary theories of aging seek to explain why such stark longevity differences exist and why a deleterious process like aging evolved. The classical mutation accumulation, antagonistic pleiotropy, and disposable soma theories predict that increased extrinsic mortality should select for the evolution of shorter lifespans and vice versa. Most experimental and comparative field studies conform to this prediction. Indeed, animals with extreme longevity (e.g., Greenland shark, bowhead whale, giant tortoise, vestimentiferan tubeworms) typically experience minimal predation. However, data from guppies, nematodes, and computational models show that increased extrinsic mortality can sometimes lead to longer evolved lifespans. The existence of theoretically immortal animals that experience extrinsic mortality - like planarian flatworms, panther worms, and hydra - further challenges classical assumptions. Octopuses pose another puzzle by exhibiting short lifespans and an uncanny intelligence, the latter of which is often associated with longevity and reduced extrinsic mortality. The evolutionary response to extrinsic mortality is likely dependent on multiple interacting factors in the organism, population, and ecology, including food availability, population density, reproductive cost, age-mortality interactions, and the mortality source.
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Affiliation(s)
| | - Maxim N Shokhirev
- Razavi Newman Integrative Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Boris Shoshitaishvili
- Division of Literatures, Cultures, and Languages, Stanford University, Stanford, CA, United States
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9
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Liberti J, Görner J, Welch M, Dosselli R, Schiøtt M, Ogawa Y, Castleden I, Hemmi JM, Baer-Imhoof B, Boomsma JJ, Baer B. Seminal fluid compromises visual perception in honeybee queens reducing their survival during additional mating flights. eLife 2019; 8:45009. [PMID: 31500699 PMCID: PMC6739865 DOI: 10.7554/elife.45009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 08/05/2019] [Indexed: 12/18/2022] Open
Abstract
Queens of social insects make all mate-choice decisions on a single day, except in honeybees whose queens can conduct mating flights for several days even when already inseminated by a number of drones. Honeybees therefore appear to have a unique, evolutionarily derived form of sexual conflict: a queen’s decision to pursue risky additional mating flights is driven by later-life fitness gains from genetically more diverse worker-offspring but reduces paternity shares of the drones she already mated with. We used artificial insemination, RNA-sequencing and electroretinography to show that seminal fluid induces a decline in queen vision by perturbing the phototransduction pathway within 24–48 hr. Follow up field trials revealed that queens receiving seminal fluid flew two days earlier than sister queens inseminated with saline, and failed more often to return. These findings are consistent with seminal fluid components manipulating queen eyesight to reduce queen promiscuity across mating flights. For social insects like honeybees it is beneficial if their queens mate with many males, because genetic diversity can protect the hive against parasites. Early in life, a honeybee queen has a short period of time in which she can fly out to mate with males before returning to the hive with all the sperm needed to last for a lifetime. Queens that have mated on their first flight may embark on additional mating flights over a few consecutive days to further increase genetic variability in their offspring. This is problematic for a male that has already mated because the more males that inseminate the queen the fewer offspring will carry on his specific genes. This results in sexual conflict between males and queens over the number of mating flights. In many animals, males manipulate females using molecules in seminal fluid to reduce the chances of the female mating again and honeybee males may use a similar strategy. Previous studies revealed that insemination alters the activity of genes related to vision in a honeybee queen’s brain. This could be one way for the males to prevent queens from embarking on additional mating flights. Now, Liberti et al. find support for this idea by showing that seminal fluid can indeed trigger changes in the activity of vision-related genes in the brains of honeybee queens, which in turn reduce a queen’s opportunity to complete additional mating flights. Queens inseminated with seminal fluid were less responsive to light compared to queens that were exposed to saline instead. Electronic tracking devices affixed to queens showed that the seminal fluid-exposed queens left for mating flights sooner but were more likely to get lost and to not return to their hives compared to the saline-exposed queens. The experiments support the idea of a sexual arms race in honeybees. Males use seminal fluid to cause rapid deteriorating vision in queens, thus reducing their likelihood of leaving the hive to mate again and to find males when they do fly again. The queens try to counteract these effects by leaving for mating flights sooner, thereby increasing offspring genetic diversity and the success of their colonies. Further studies will be needed to find out how the honeybee sexual arms race varies across seasons, bee races, and geographic ranges. Such information will be useful for honeybee breeding programs, which rely on queen mating success and hive genetic diversity to ensure hive health.
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Affiliation(s)
- Joanito Liberti
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Julia Görner
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia
| | - Mat Welch
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia
| | - Ryan Dosselli
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia.,Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, Australia
| | - Morten Schiøtt
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Yuri Ogawa
- School of Animal Biology and UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Ian Castleden
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia
| | - Jan M Hemmi
- School of Animal Biology and UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Barbara Baer-Imhoof
- Centre for Integrative Bee Research (CIBER), Department of Entomology, University of California, Riverside, Riverside, United States
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), Department of Entomology, University of California, Riverside, Riverside, United States
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Gradish AE, van der Steen J, Scott-Dupree CD, Cutler GC, Goulson D, Klein O, Lehmann DM, Lückmann J, O’Neill B, Raine NE, Sharma B, Thompson H. Comparison of Pesticide Exposure in Honey Bees (Hymenoptera: Apidae) and Bumble Bees (Hymenoptera: Apidae): Implications for Risk Assessments. ENVIRONMENTAL ENTOMOLOGY 2019; 48:12-21. [PMID: 30508078 PMCID: PMC8215506 DOI: 10.1093/ee/nvy168] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Indexed: 05/07/2023]
Abstract
To date, regulatory pesticide risk assessments have relied on the honey bee (Apis mellifera L.) (Hymenoptera: Apidae) as a surrogate test species for estimating the risk of pesticide exposure to all bee species. However, honey bees and non-Apis bees may differ in their susceptibility and exposure to pesticides. In 2017, a workshop ('Pesticide Exposure Assessment Paradigm for Non-Apis Bees') was held to assess if honey bee risk assessment frameworks are reflective of non-Apis bee pesticide exposure. In this article, we summarize the workshop discussions on bumble bees (Bombus spp.). We review the life history and foraging behavior of bumble bees and honey bees and discuss how these traits may influence routes and levels of exposure for both taxa. Overall, the major pesticide exposure routes for bumble bees and honey bees are similar; however, bumble bees face additional exposure routes (direct exposure of foraging queens and exposure of larvae and adults to soil residues). Furthermore, bumble bees may receive comparatively higher pesticide doses via contact or oral exposure. We conclude that honey bee pesticide risk assessments may not always be protective of bumble bees, especially queens, in terms of exposure. Data needed to reliably quantify pesticide exposure for bumble bees (e.g., food consumption rates, soil residue levels) are lacking. Addressing these knowledge gaps will be crucial before bumble bee exposure can be incorporated into the pesticide risk assessment process. Because bumble bees exhibit appreciable interspecific variation in colony and behavioral characteristics, data relevant to pesticide exposure should be generated for multiple species.
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Affiliation(s)
- Angela E. Gradish
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Jozef van der Steen
- Wageningen University & Research, Netherlands
- Alveus AB Consultancy, Oisterwijk, Netherlands
| | | | | | - Dave Goulson
- School of Life Sciences, University of Sussex, BN1 9QG, UK
| | - Olaf Klein
- Eurofins Agroscience Services Ecotox GmbH, 75223 Niefern-Oeschelbronn, Germany
| | - David M. Lehmann
- Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health, and Environmental Effects Laboratory (NHEERL), US Environmental Protection Agency, Research Triangle Park, NC, USA
| | | | - Bridget O’Neill
- Corteva Agrisciences, 9330 Zionsville Road, 306/B2-2247, Indianapolis, IN 46268, USA
| | - Nigel E. Raine
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Bibek Sharma
- Global Regulatory Sciences, FMC Corporation, 701/801 Princeton South Corp Ctr, Ewing, NJ 08886, USA
| | - Helen Thompson
- Syngenta, Jealott’s Hill International Research Station, Bracknell, Berkshire RG42 6EY, UK
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12
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Almond EJ, Huggins TJ, Crowther LP, Parker JD, Bourke AFG. Queen Longevity and Fecundity Affect Conflict with Workers over Resource Inheritance in a Social Insect. Am Nat 2018; 193:256-266. [PMID: 30720369 DOI: 10.1086/701299] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Resource inheritance is a major source of conflict in animal societies. However, the assumptions and predictions of models of conflict over resource inheritance have not been systematically tested within a single system. We developed an inclusive fitness model for annual eusocial Hymenoptera that predicts a zone of conflict in which future reproductive workers are selected to enforce nest inheritance before the queen is selected to cede the nest. We experimentally tested key elements of this model in the bumblebee Bombus terrestris. In colonies from which queens were sequentially removed, queen tenure was significantly negatively associated with worker male production, confirming that workers gain direct fitness by usurping the queen. In unmanipulated colonies, queen fecundity decreased significantly over the latter part of the colony cycle, confirming that workers' indirect fitness from maintaining queens declines over time. Finally, in an experiment simulating loss of queen fecundity by removal of queens' eggs, worker-to-queen aggression increased significantly and aggressive workers were significantly more likely to become egg layers, consistent with workers monitoring queen fecundity to assess the net benefit of future reproduction. Overall, by upholding key assumptions and predictions of the model, our results provide novel empirical support for kin-selected conflict over resource inheritance.
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13
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Becher MA, Twiston-Davies G, Penny TD, Goulson D, Rotheray EL, Osborne JL. Bumble-BEEHAVE: A systems model for exploring multifactorial causes of bumblebee decline at individual, colony, population and community level. J Appl Ecol 2018; 55:2790-2801. [PMID: 30449898 PMCID: PMC6221040 DOI: 10.1111/1365-2664.13165] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/23/2018] [Indexed: 12/03/2022]
Abstract
World‐wide declines in pollinators, including bumblebees, are attributed to a multitude of stressors such as habitat loss, resource availability, emerging viruses and parasites, exposure to pesticides, and climate change, operating at various spatial and temporal scales. Disentangling individual and interacting effects of these stressors, and understanding their impact at the individual, colony and population level are a challenge for systems ecology. Empirical testing of all combinations and contexts is not feasible. A mechanistic multilevel systems model (individual‐colony‐population‐community) is required to explore resilience mechanisms of populations and communities under stress. We present a model which can simulate the growth, behaviour and survival of six UK bumblebee species living in any mapped landscape. Bumble‐BEEHAVE simulates, in an agent‐based approach, the colony development of bumblebees in a realistic landscape to study how multiple stressors affect bee numbers and population dynamics. We provide extensive documentation, including sensitivity analysis and validation, based on data from literature. The model is freely available, has flexible settings and includes a user manual to ensure it can be used by researchers, farmers, policy‐makers, NGOs or other interested parties. Model outcomes compare well with empirical data for individual foraging behaviour, colony growth and reproduction, and estimated nest densities. Simulating the impact of reproductive depression caused by pesticide exposure shows that the complex feedback mechanisms captured in this model predict higher colony resilience to stress than suggested by a previous, simpler model. Synthesis and applications. The Bumble‐BEEHAVE model represents a significant step towards predicting bumblebee population dynamics in a spatially explicit way. It enables researchers to understand the individual and interacting effects of the multiple stressors affecting bumblebee survival and the feedback mechanisms that may buffer a colony against environmental stress, or indeed lead to spiralling colony collapse. The model can be used to aid the design of field experiments, for risk assessments, to inform conservation and farming decisions and for assigning bespoke management recommendations at a landscape scale.
The Bumble‐BEEHAVE model represents a significant step towards predicting bumblebee population dynamics in a spatially explicit way. It enables researchers to understand the individual and interacting effects of the multiple stressors affecting bumblebee survival and the feedback mechanisms that may buffer a colony against environmental stress, or indeed lead to spiralling colony collapse. The model can be used to aid the design of field experiments, for risk assessments, to inform conservation and farming decisions and for assigning bespoke management recommendations at a landscape scale.
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Affiliation(s)
- Matthias A Becher
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK
| | - Grace Twiston-Davies
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK
| | - Tim D Penny
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK.,School of Biological and Chemical Sciences Queen Mary University of London London UK
| | - Dave Goulson
- School of Life Sciences University of Sussex Sussex UK
| | | | - Juliet L Osborne
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK
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14
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Wu-Smart J, Spivak M. Effects of neonicotinoid imidacloprid exposure on bumble bee (Hymenoptera: Apidae) queen survival and nest initiation. ENVIRONMENTAL ENTOMOLOGY 2018; 47:55-62. [PMID: 29244130 DOI: 10.1093/ee/nvx175] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Indexed: 06/07/2023]
Abstract
Neonicotinoids are highly toxic to insects and may systemically translocate to nectar and pollen of plants where foraging bees may become exposed. Exposure to neonicotinoids can induce detrimental sublethal effects on individual and colonies of bees and may have long-term impacts, such as impaired foraging, reduced longevity, and reduced brood care or production. Less well-studied are the potential effects on queen bumble bees that may become exposed while foraging in the spring during colony initiation. This study assessed queen survival and nest founding in caged bumble bees [Bombus impatiens (Cresson) (Hymenoptera: Apidae)] after chronic (18-d) dietary exposure of imidacloprid in syrup (1, 5, 10, and 25 ppb) and pollen (0.3, 1.7, 3.3, and 8.3 ppb), paired respectively. Here we show some mortality in queens exposed at all doses even as low as 1 ppb, and, compared with untreated queens, significantly reduced survival of treated queens at the two highest doses. Queens that survived initial imidacloprid exposure commenced nest initiation; however, they exhibited dose-dependent delay in egg-laying and emergence of worker brood. Furthermore, imidacloprid treatment affected other parameters such as nest and queen weight. This study is the first to show direct impacts of imidacloprid at field-relevant levels on individual B. impatiens queen survival and nest founding, indicating that bumble bee queens are particularly sensitive to neonicotinoids when directly exposed. This study also helps focus pesticide risk mitigation efforts and highlights the importance of reducing exposure rates in the early spring when bumble bee queens, and other wild bees are foraging and initiating nests.
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Affiliation(s)
- Judy Wu-Smart
- University of Nebraska-Lincoln, Entomology, Lincoln, NE
| | - Marla Spivak
- University of Minnesota, Entomology, Saint Paul, MN
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15
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Blacher P, Huggins TJ, Bourke AFG. Evolution of ageing, costs of reproduction and the fecundity-longevity trade-off in eusocial insects. Proc Biol Sci 2018; 284:rspb.2017.0380. [PMID: 28701554 PMCID: PMC5524490 DOI: 10.1098/rspb.2017.0380] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/07/2017] [Indexed: 01/04/2023] Open
Abstract
Eusocial insects provide special opportunities to elucidate the evolution of ageing as queens have apparently evaded costs of reproduction and reversed the fecundity–longevity trade-off generally observed in non-social organisms. But how reproduction affects longevity in eusocial insects has rarely been tested experimentally. In this study, we took advantage of the reproductive plasticity of workers to test the causal role of reproduction in determining longevity in eusocial insects. Using the eusocial bumblebee Bombus terrestris, we found that, in whole colonies, in which workers could freely ‘choose’ whether to become reproductive, workers' level of ovarian activation was significantly positively associated with longevity and ovary-active workers significantly outlived ovary-inactive workers. By contrast, when reproductivity was experimentally induced in randomly selected workers, thereby decoupling it from other traits, workers' level of ovarian activation was significantly negatively associated with longevity and ovary-active workers were significantly less long-lived than ovary-inactive workers. These findings show that workers experience costs of reproduction and suggest that intrinsically high-quality individuals can overcome these costs. They also raise the possibility that eusocial insect queens exhibit condition-dependent longevity and hence call into question whether eusociality entails a truly reversed fecundity–longevity trade-off involving a fundamental remodelling of conserved genetic and endocrine networks underpinning ageing.
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Affiliation(s)
- Pierre Blacher
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Timothy J Huggins
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Andrew F G Bourke
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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16
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17
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Carvell C, Bourke AFG, Dreier S, Freeman SN, Hulmes S, Jordan WC, Redhead JW, Sumner S, Wang J, Heard MS. Bumblebee family lineage survival is enhanced in high-quality landscapes. Nature 2017; 543:547-549. [DOI: 10.1038/nature21709] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 02/15/2017] [Indexed: 02/05/2023]
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18
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Schrempf A, Giehr J, Röhrl R, Steigleder S, Heinze J. Royal Darwinian Demons: Enforced Changes in Reproductive Efforts Do Not Affect the Life Expectancy of Ant Queens. Am Nat 2017; 189:436-442. [PMID: 28350504 DOI: 10.1086/691000] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
One of the central tenets of life-history theory is that organisms cannot simultaneously maximize all fitness components. This results in the fundamental trade-off between reproduction and life span known from numerous animals, including humans. Social insects are a well-known exception to this rule: reproductive queens outlive nonreproductive workers. Here, we take a step forward and show that under identical social and environmental conditions the fecundity-longevity trade-off is absent also within the queen caste. A change in reproduction did not alter life expectancy, and even a strong enforced increase in reproductive efforts did not reduce residual life span. Generally, egg-laying rate and life span were positively correlated. Queens of perennial social insects thus seem to maximize at the same time two fitness parameters that are normally negatively correlated. Even though they are not immortal, they best approach a hypothetical "Darwinian demon" in the animal kingdom.
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19
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Metzler S, Heinze J, Schrempf A. Mating and longevity in ant males. Ecol Evol 2016; 6:8903-8906. [PMID: 28035278 PMCID: PMC5192810 DOI: 10.1002/ece3.2474] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 08/01/2016] [Indexed: 11/23/2022] Open
Abstract
Across multicellular organisms, the costs of reproduction and self‐maintenance result in a life history trade‐off between fecundity and longevity. Queens of perennial social Hymenoptera are both highly fertile and long‐lived, and thus, this fundamental trade‐off is lacking. Whether social insect males similarly evade the fecundity/longevity trade‐off remains largely unstudied. Wingless males of the ant genus Cardiocondyla stay in their natal colonies throughout their relatively long lives and mate with multiple female sexuals. Here, we show that Cardiocondyla obscurior males that were allowed to mate with large numbers of female sexuals had a shortened life span compared to males that mated at a low frequency or virgin males. Although frequent mating negatively affects longevity, males clearly benefit from a “live fast, die young strategy” by inseminating as many female sexuals as possible at a cost to their own survival.
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Affiliation(s)
- Sina Metzler
- Zoology/Evolutionary Biology University of Regensburg Regensburg Germany; IST Austria (Institute of Science and Technology Austria) Klosterneuburg Austria
| | - Jürgen Heinze
- Zoology/Evolutionary Biology University of Regensburg Regensburg Germany
| | - Alexandra Schrempf
- Zoology/Evolutionary Biology University of Regensburg Regensburg Germany
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20
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Field J, Leadbeater E. Cooperation between non-relatives in a primitively eusocial paper wasp, Polistes dominula. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150093. [PMID: 26729932 DOI: 10.1098/rstb.2015.0093] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In cooperatively breeding vertebrates, the existence of individuals that help to raise the offspring of non-relatives is well established, but unrelated helpers are less well known in the social insects. Eusocial insect groups overwhelmingly consist of close relatives, so populations where unrelated helpers are common are intriguing. Here, we focus on Polistes dominula-the best-studied primitively eusocial wasp, and a species in which nesting with non-relatives is not only present but frequent. We address two major questions: why individuals should choose to nest with non-relatives, and why such individuals participate in the costly rearing of unrelated offspring. Polistes dominula foundresses produce more offspring of their own as subordinates than when they nest independently, providing a potential explanation for co-founding by non-relatives. There is some evidence that unrelated subordinates tailor their behaviour towards direct fitness, while the role of recognition errors in generating unrelated co-foundresses is less clear. Remarkably, the remote but potentially highly rewarding chance of inheriting the dominant position appears to strongly influence behaviour, suggesting that primitively eusocial insects may have much more in common with their social vertebrate counterparts than has commonly been thought.
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Affiliation(s)
- Jeremy Field
- School of Life Sciences, University of Sussex, John Maynard Smith Building, Falmer, Brighton BN1 9QG, UK
| | - Ellouise Leadbeater
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
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21
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Cabrera AR, Almanza MT, Cutler GC, Fischer DL, Hinarejos S, Lewis G, Nigro D, Olmstead A, Overmyer J, Potter DA, Raine NE, Stanley-Stahr C, Thompson H, van der Steen J. Initial recommendations for higher-tier risk assessment protocols for bumble bees, Bombus spp. (Hymenoptera: Apidae). INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2016; 12:222-9. [PMID: 26108565 DOI: 10.1002/ieam.1675] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/08/2014] [Accepted: 06/15/2015] [Indexed: 05/14/2023]
Abstract
Global declines of bumble bees and other pollinator populations are of concern because of their critical role for crop production and maintenance of wild plant biodiversity. Although the consensus among scientists is that the interaction of many factors, including habitat loss, forage scarcity, diseases, parasites, and pesticides, potentially plays a role in causing these declines, pesticides have received considerable attention and scrutiny. In response, regulatory agencies have introduced more stringent pollinator testing requirements for registration and reregistration of pesticides, to ensure that the risks to pollinators are minimized. In this context, guidelines for testing bumble bees (Bombus spp.) in regulatory studies are not yet available, and a pressing need exists to develop suitable protocols for routine higher-tier studies with these non-Apis sp., social bees. To meet this need, Bayer CropScience LP, Syngenta Crop Protection LLC US, and Valent USA. Corporation organized a workshop bringing together a group of global experts on bumble bee behavior, ecology, and ecotoxicology to discuss and develop draft protocols for both semi-field (Tier II) and field (Tier III) studies. The workshop was held May 8-9, 2014, at the Bayer Bee Care Center, North Carolina, USA. The participants represented academic, consulting, and industry scientists from Europe, Canada, the United States, and Brazil. The workshop identified a clear protection goal and generated proposals for basic experimental designs, relevant measurements, and endpoints for both semifield (tunnel) and field tests. These initial recommendations are intended to form the basis of discussions to help advance the development of appropriate protocol guidelines.
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Affiliation(s)
- Ana R Cabrera
- Bayer CropScience LP, Research Triangle Park, North Carolina, USA
| | | | - G Christopher Cutler
- Department of Environmental Sciences, Dalhousie University, Truro, Nova Scotia, Canada
| | - David L Fischer
- Bayer CropScience LP, Research Triangle Park, North Carolina, USA
| | - Silvia Hinarejos
- Sumitomo Chemical Agro Europe SAS, Parc d'affaires de Crécy, Saint Didier au Mont d'Or, France
| | - Gavin Lewis
- JSC International Limited, The Exchange, Station Parade, Harrogate, United Kingdom
| | - Daniel Nigro
- Bayer CropScience, Recanto dos Passaros, Paulinia, SP, Brazil
| | - Allen Olmstead
- Bayer CropScience LP, Research Triangle Park, North Carolina, USA
| | - Jay Overmyer
- Syngenta Crop Protection LLC, Greensboro, North Carolina, USA
| | - Daniel A Potter
- Department of Entomology, University of Kentucky, Lexington, Kentucky, USA
| | - Nigel E Raine
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Cory Stanley-Stahr
- Entomology and Nematology Department, University of Florida, Gainesville, Florida, USA
| | - Helen Thompson
- Syngenta LTD, Jealott's Hill International Research Station, Bracknell, Berkshire, UK
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22
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Lockett GA, Almond EJ, Huggins TJ, Parker JD, Bourke AFG. Gene expression differences in relation to age and social environment in queen and worker bumble bees. Exp Gerontol 2016; 77:52-61. [PMID: 26883339 DOI: 10.1016/j.exger.2016.02.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 01/24/2016] [Accepted: 02/12/2016] [Indexed: 02/03/2023]
Abstract
Eusocial insects provide special insights into the genetic pathways influencing aging because of their long-lived queens and flexible aging schedules. Using qRT-PCR in the primitively eusocial bumble bee Bombus terrestris (Linnaeus), we investigated expression levels of four candidate genes associated with taxonomically widespread age-related pathways (coenzyme Q biosynthesis protein 7, COQ7; DNA methyltransferase 3, Dnmt3; foraging, for; and vitellogenin, vg). In Experiment 1, we tested how expression changes with queen relative age and productivity. We found a significant age-related increase in COQ7 expression in queen ovary. In brain, all four genes showed higher expression with increasing female (queen plus worker) production, with this relationship strengthening as queen age increased, suggesting a link with the positive association of fecundity and longevity found in eusocial insect queens. In Experiment 2, we tested effects of relative age and social environment (worker removal) in foundress queens and effects of age and reproductive status in workers. In this experiment, workerless queens showed significantly higher for expression in brain, as predicted if downregulation of for is associated with the cessation of foraging by foundress queens following worker emergence. Workers showed a significant age-related increase in Dnmt3 expression in fat body, suggesting a novel association between aging and methylation in B. terrestris. Ovary activation was associated with significantly higher vg expression in fat body and, in younger workers, in brain, consistent with vitellogenin's ancestral role in regulating egg production. Overall, our findings reveal a mixture of novel and conserved features in age-related genetic pathways under primitive eusociality.
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Affiliation(s)
- Gabrielle A Lockett
- School of Biological Sciences, University of Southampton, Life Sciences Building, Highfield Campus, Southampton SO17 1BJ, UK
| | - Edward J Almond
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Timothy J Huggins
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Joel D Parker
- School of Biological Sciences, University of Southampton, Life Sciences Building, Highfield Campus, Southampton SO17 1BJ, UK
| | - Andrew F G Bourke
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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23
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Kramer BH, Schrempf A, Scheuerlein A, Heinze J. Ant Colonies Do Not Trade-Off Reproduction against Maintenance. PLoS One 2015; 10:e0137969. [PMID: 26383861 PMCID: PMC4575186 DOI: 10.1371/journal.pone.0137969] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/24/2015] [Indexed: 11/22/2022] Open
Abstract
The question on how individuals allocate resources into maintenance and reproduction is one of the central questions in life history theory. Yet, resource allocation into maintenance on the organismic level can only be measured indirectly. This is different in a social insect colony, a "superorganism" where workers represent the soma and the queen the germ line of the colony. Here, we investigate whether trade-offs exist between maintenance and reproduction on two levels of biological organization, queens and colonies, by following single-queen colonies of the ant Cardiocondyla obscurior throughout the entire lifespan of the queen. Our results show that maintenance and reproduction are positively correlated on the colony level, and we confirm results of an earlier study that found no trade-off on the individual (queen) level. We attribute this unexpected outcome to the existence of a positive feedback loop where investment into maintenance (workers) increases the rate of resource acquisition under laboratory conditions. Even though food was provided ad libitum, variation in productivity among the colonies suggests that resources can only be utilized and invested into additional maintenance and reproduction by the colony if enough workers are available. The resulting relationship between per-capita and colony productivity in our study fits well with other studies conducted in the field, where decreasing per-capita productivity and the leveling off of colony productivity have been linked to density dependent effects due to competition among colonies. This suggests that the absence of trade-offs in our laboratory study might also be prevalent under natural conditions, leading to a positive association of maintenance, (= growth) and reproduction. In this respect, insect colonies resemble indeterminate growing organisms.
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Affiliation(s)
- Boris H. Kramer
- Max-Planck-Institute for Demographic Research, Konrad-Zuse-Str. 1, D-18055, Rostock, Germany
| | - Alexandra Schrempf
- Zoology / Evolutionary Biology lab, University of Regensburg, Universitätsstraße 31, D-93040, Regensburg, Germany
| | - Alexander Scheuerlein
- Max-Planck-Institute for Demographic Research, Konrad-Zuse-Str. 1, D-18055, Rostock, Germany
| | - Jürgen Heinze
- Zoology / Evolutionary Biology lab, University of Regensburg, Universitätsstraße 31, D-93040, Regensburg, Germany
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24
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Cueva del Castillo R, Sanabria‐Urbán S, Serrano‐Meneses MA. Trade-offs in the evolution of bumblebee colony and body size: a comparative analysis. Ecol Evol 2015; 5:3914-26. [PMID: 26445652 PMCID: PMC4588658 DOI: 10.1002/ece3.1659] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 07/16/2015] [Accepted: 07/22/2015] [Indexed: 11/26/2022] Open
Abstract
Trade-offs between life-history traits - such as fecundity and survival - have been demonstrated in several studies. In eusocial insects, the number of organisms and their body sizes can affect the fitness of the colony. Large-than-average body sizes as well as more individuals can improve a colony's thermoregulation, foraging efficiency, and fecundity. However, in bumblebees, large colonies and large body sizes depend largely on high temperatures and a large amount of food resources. Bumblebee taxa can be found in temperate and tropical regions of the world and differ markedly in their colony sizes and body sizes. Variation in colony size and body size may be explained by the costs and benefits associated with the evolutionary history of each species in a particular environment. In this study, we explored the effect of temperature and precipitation (the latter was used as an indirect indicator of food availability) on the colony and body size of twenty-one bumblebee taxa. A comparative analysis controlling for phylogenetic effects as well as for the body size of queens, workers, and males in bumblebee taxa from temperate and tropical regions indicated that both temperature and precipitation affect colony and body size. We found a negative association between colony size and the rainiest trimester, and a positive association between the colony size and the warmest month of the year. In addition, male bumblebees tend to evolve larger body sizes in places where the rain occurs mostly in the summer and the overall temperature is warmer. Moreover, we found a negative relationship between colony size and body sizes of queens, workers, and males, suggesting potential trade-offs in the evolution of bumblebee colony and body size.
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Affiliation(s)
- Raúl Cueva del Castillo
- Lab. de Ecología; UBIPROUniversidad Nacional Autónoma de MéxicoFES Iztacala. A. P. 31454090Edo. MéxicoMéxico
| | - Salomón Sanabria‐Urbán
- Lab. de Ecología; UBIPROUniversidad Nacional Autónoma de MéxicoFES Iztacala. A. P. 31454090Edo. MéxicoMéxico
| | - Martín Alejandro Serrano‐Meneses
- Laboratorio de Biología EvolutivaCentro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaCarretera Tlaxcala‐Puebla Km. 1.590062TlaxcalaMéxico
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25
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Carvell C, Bourke AF, Osborne JL, Heard MS. Effects of an agri-environment scheme on bumblebee reproduction at local and landscape scales. Basic Appl Ecol 2015. [DOI: 10.1016/j.baae.2015.05.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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26
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Holland JG, Bourke AFG. Colony and individual life‐history responses to temperature in a social insect pollinator. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12480] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Jacob G. Holland
- School of Biological Sciences University of East Anglia Norwich Research ParkNorwich Norfolk NR4 7TJ UK
| | - Andrew F. G. Bourke
- School of Biological Sciences University of East Anglia Norwich Research ParkNorwich Norfolk NR4 7TJ UK
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27
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Gill RJ, Raine NE. Chronic impairment of bumblebee natural foraging behaviour induced by sublethal pesticide exposure. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12292] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Richard J. Gill
- School of Biological Sciences; Royal Holloway University of London; Egham Surrey TW20 0EX UK
| | - Nigel E. Raine
- School of Biological Sciences; Royal Holloway University of London; Egham Surrey TW20 0EX UK
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28
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Dreier S, Redhead JW, Warren IA, Bourke AFG, Heard MS, Jordan WC, Sumner S, Wang J, Carvell C. Fine-scale spatial genetic structure of common and declining bumble bees across an agricultural landscape. Mol Ecol 2014; 23:3384-95. [PMID: 24980963 PMCID: PMC4142012 DOI: 10.1111/mec.12823] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 05/07/2014] [Accepted: 05/21/2014] [Indexed: 02/04/2023]
Abstract
Land-use changes have threatened populations of many insect pollinators, including bumble bees. Patterns of dispersal and gene flow are key determinants of species' ability to respond to land-use change, but have been little investigated at a fine scale (<10 km) in bumble bees. Using microsatellite markers, we determined the fine-scale spatial genetic structure of populations of four common Bombus species (B. terrestris, B. lapidarius, B. pascuorum and B. hortorum) and one declining species (B. ruderatus) in an agricultural landscape in Southern England, UK. The study landscape contained sown flower patches representing agri-environment options for pollinators. We found that, as expected, the B. ruderatus population was characterized by relatively low heterozygosity, number of alleles and colony density. Across all species, inbreeding was absent or present but weak (FIS = 0.01-0.02). Using queen genotypes reconstructed from worker sibships and colony locations estimated from the positions of workers within these sibships, we found that significant isolation by distance was absent in B. lapidarius, B. hortorum and B. ruderatus. In B. terrestris and B. pascuorum, it was present but weak; for example, in these two species, expected relatedness of queens founding colonies 1 m apart was 0.02. These results show that bumble bee populations exhibit low levels of spatial genetic structure at fine spatial scales, most likely because of ongoing gene flow via widespread queen dispersal. In addition, the results demonstrate the potential for agri-environment scheme conservation measures to facilitate fine-scale gene flow by creating a more even distribution of suitable habitats across landscapes.
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Affiliation(s)
- Stephanie Dreier
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK; School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK
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29
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Baron GL, Raine NE, Brown MJF. Impact of chronic exposure to a pyrethroid pesticide on bumblebees and interactions with a trypanosome parasite. J Appl Ecol 2014. [DOI: 10.1111/1365-2664.12205] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Gemma L. Baron
- School of Biological Sciences Royal Holloway University of London Egham Surrey TW20 0EX UK
| | - Nigel E. Raine
- School of Biological Sciences Royal Holloway University of London Egham Surrey TW20 0EX UK
| | - Mark J. F. Brown
- School of Biological Sciences Royal Holloway University of London Egham Surrey TW20 0EX UK
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Blacher P, Boreggio L, Leroy C, Devienne P, Châline N, Chameron S. Specific recognition of reproductive parasite workers by nest-entrance guards in the bumble bee Bombus terrestris. Front Zool 2013; 10:74. [PMID: 24321042 PMCID: PMC3878879 DOI: 10.1186/1742-9994-10-74] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 12/06/2013] [Indexed: 11/29/2022] Open
Abstract
Background The impact of social parasites on their hosts’ fitness is a strong selective pressure that can lead to the evolution of adapted defence strategies. Guarding the nest to prevent the intrusion of parasites is a widespread response of host species. If absolute rejection of strangers provides the best protection against parasites, more fine-tuned strategies can prove more adaptive. Guarding is indeed costly and not all strangers constitute a real threat. That is particularly true for worker reproductive parasitism in social insects since only a fraction of non-nestmate visitors, the fertile ones, can readily engage in parasitic reproduction. Guards should thus be more restrictive towards fertile than sterile non-nestmate workers. We here tested this hypothesis by examining the reaction of nest-entrance guards towards nestmate and non-nestmate workers with varying fertility levels in the bumble bee Bombus terrestris. Because social recognition in social insects mainly relies on cuticular lipids (CLs), chemical analysis was also conducted to examine whether workers’ CLs could convey the relevant information upon which guards could base their decision. We thus aimed to determine whether an adapted defensive strategy to worker reproductive parasitism has evolved in B. terrestris colonies. Results Chemical analysis revealed that the cuticular chemical profiles of workers encode information about both their colony membership and their current fertility, therefore providing potential recognition cues for a suitable adjustment of the guards’ defensive decisions. We found that guards were similarly tolerant towards sterile non-nestmate workers than towards nestmate workers. However, as predicted, guards responded more aggressively towards fertile non-nestmates. Conclusion Our results show that B. terrestris guards discriminate non-nestmates that differ in their reproductive potential and respond more strongly to the individuals that are a greatest threat for the colony. Cuticular hydrocarbons are the probable cues underlying the specific recognition of reproductive parasites, with the specific profile of highly fertile bees eliciting the agonistic response when combined with non-colony membership information. Our study therefore provides a first piece of empirical evidence supporting the hypothesis that an adapted defensive strategy against worker reproductive parasitism exists in B. terrestris colonies.
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Affiliation(s)
- Pierre Blacher
- Laboratoire d'Ethologie Expérimentale et Comparée E,A, 4443, Université Paris 13, Sorbonne Paris Cité, 93430 Villetaneuse, France.
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31
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Heinze J, Frohschammer S, Bernadou A. Queen life-span and total reproductive success are positively associated in the ant Cardiocondyla cf. kagutsuchi. Behav Ecol Sociobiol 2013. [DOI: 10.1007/s00265-013-1567-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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32
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Holland JG, Guidat FS, Bourke AFG. Queen control of a key life-history event in a eusocial insect. Biol Lett 2013; 9:20130056. [PMID: 23637392 DOI: 10.1098/rsbl.2013.0056] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In eusocial insects, inclusive fitness theory predicts potential queen-worker conflict over the timing of events in colony life history. Whether queens or workers control the timing of these events is poorly understood. In the bumble-bee Bombus terrestris, queens exhibit a 'switch point' in which they switch from laying diploid eggs yielding females (workers and new queens) to laying haploid eggs yielding males. By rearing foundress queens whose worker offspring were removed as pupae and sexing their eggs using microsatellite genotyping, we found that queens kept in the complete absence of adult workers still exhibit a switch point. Moreover, the timing of their switch points relative to the start of egg-laying did not differ significantly from that of queens allowed to produce normal colonies. The finding that bumble-bee queens can express the switch point in the absence of workers experimentally demonstrates queen control of a key life-history event in eusocial insects. In addition, we found no evidence that workers affect the timing of the switch point either directly or indirectly via providing cues to queens, suggesting that workers do not fully express their interests in queen-worker conflicts over colony life history.
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Affiliation(s)
- Jacob G Holland
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk NR4 7TJ, UK.
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33
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Green JP, Leadbeater E, Carruthers JM, Rosser NS, Lucas ER, Field J. Clypeal patterning in the paper wasp Polistes dominulus: no evidence of adaptive value in the wild. Behav Ecol 2013. [DOI: 10.1093/beheco/ars226] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Zanette LRS, Miller SDL, Faria CMA, Almond EJ, Huggins TJ, Jordan WC, Bourke AFG. Reproductive conflict in bumblebees and the evolution of worker policing. Evolution 2012. [PMID: 23206135 DOI: 10.1111/j.1558-5646.2012.01709.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Worker policing (mutual repression of reproduction) in the eusocial Hymenoptera represents a leading example of how coercion can facilitate cooperation. The occurrence of worker policing in "primitively" eusocial species with low mating frequencies, which lack relatedness differences conducive to policing, suggests that separate factors may underlie the origin and maintenance of worker policing. We tested this hypothesis by investigating conflict over male parentage in the primitively eusocial, monandrous bumblebee, Bombus terrestris. Using observations, experiments, and microsatellite genotyping, we found that: (a) worker- but not queen-laid male eggs are nearly all eaten (by queens, reproductive, and nonreproductive workers) soon after being laid, so accounting for low observed frequencies of larval and adult worker-produced males; (b) queen- and worker-laid male eggs have equal viabilities; (c) workers discriminate between queen- and worker-laid eggs using cues on eggs and egg cells that almost certainly originate from queens. The cooccurrence in B. terrestris of these three key elements of "classical" worker policing as found in the highly eusocial, polyandrous honeybees provides novel support for the hypothesis that worker policing can originate in the absence of relatedness differences maintaining it. Worker policing in B. terrestris almost certainly arose via reproductive competition among workers, that is, as "selfish" policing.
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Affiliation(s)
- Lorenzo R S Zanette
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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35
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PERRARD A, VILLEMANT C, CARPENTER JM, BAYLAC M. Differences in caste dimorphism among three hornet species (Hymenoptera: Vespidae): forewing size, shape and allometry. J Evol Biol 2012; 25:1389-98. [DOI: 10.1111/j.1420-9101.2012.02527.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Terminal investment: individual reproduction of ant queens increases with age. PLoS One 2012; 7:e35201. [PMID: 22509399 PMCID: PMC3324418 DOI: 10.1371/journal.pone.0035201] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 03/13/2012] [Indexed: 11/24/2022] Open
Abstract
The pattern of age-specific fecundity is a key component of the life history of organisms and shapes their ecology and evolution. In numerous animals, including humans, reproductive performance decreases with age. Here, we demonstrate that some social insect queens exhibit the opposite pattern. Egg laying rates of Cardiocondyla obscurior ant queens increased with age until death, even when the number of workers caring for them was kept constant. Cardiocondyla, and probably also other ants, therefore resemble the few select organisms with similar age-specific reproductive investment, such as corals, sturgeons, or box turtles (e.g., [1]), but they differ in being more short-lived and lacking individual, though not social, indeterminate growth. Furthermore, in contrast to most other organisms, in which average life span declines with increasing reproductive effort, queens with high egg laying rates survived as long as less fecund queens.
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Tsuji K, Kikuta N, Kikuchi T. Determination of the cost of worker reproduction via diminished life span in the ant Diacamma sp. Evolution 2011; 66:1322-31. [PMID: 22519774 DOI: 10.1111/j.1558-5646.2011.01522.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Workers of social Hymenoptera can usually produce male offspring, but rarely do so in the presence of a queen despite the potential individual fitness benefit. Various mechanisms have been hypothesized to regulate worker reproduction, including avoiding the colony-level cost of worker reproduction. However, firm quantitative evidence is lacking to support that hypothesis. Here, we accurately quantified this cost by studying an ant species (Diacamma sp.) in which worker reproduction is rare in the presence of the gamergate (the functional queen). A series of experiments to manipulate worker-gamergate contact revealed that short-term brood-production efficiency is not changed by the presence of worker reproduction. However, when workers reproduce, their average life span is reduced to between 74% and 88% of that in the absence of reproduction, indicating a long-term cost to the colony. In theory, this cost can explain the policing of worker reproduction under a queen-single mating system, but the cost does not appear to be high enough to stop worker reproduction. When contact with the gamergate is lost, it is only the nonreproductive workers whose life span was reduced; the reproductive workers lived as long as nonorphaned workers. We suggest that an increased workload can account for the reduction in life span better than a trade-off between reproduction and longevity.
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Affiliation(s)
- Kazuki Tsuji
- Department of Agro-Environmental Sciences, University of the Ryukyus (The United Graduate School of Agricultural Sciences, Kagoshima University), Okinawa 903-0213, Japan.
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38
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DuVal EH. Variation in annual and lifetime reproductive success of lance-tailed manakins: alpha experience mitigates effects of senescence on siring success. Proc Biol Sci 2011; 279:1551-9. [PMID: 22090386 DOI: 10.1098/rspb.2011.1840] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The causes of variation in individual reproductive success over a lifetime are not well understood. In long-lived vertebrates, reproductive output usually increases during early adulthood, but it is difficult to disentangle the roles of development and learning on this gain of reproductive success. Lekking lance-tailed manakins provide an opportunity to separate these processes, as the vast majority of male reproduction occurs after a bird obtains alpha status and maintains a display area in the lek, but the age at which males achieve alpha status varies widely. Using 11 years of longitudinal data on age, social status and genetic siring success, I assessed the factors influencing variation in siring success by individuals over their lifetimes. The data show increases in annual reproductive success with both age and alpha experience. At advanced ages, these gains were offset by senescence in fecundity. Individual ontogeny, rather than compositional change of the population, generated a nonlinear relationship of breeding tenure with lifetime success; age of assuming alpha status was unrelated to tenure as a breeder, or success in the alpha role. Importantly, these findings suggest that social experience can mitigate the negative effects of senescence in older breeders.
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Affiliation(s)
- Emily H DuVal
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306-4295, USA.
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39
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Carvell C, Osborne JL, Bourke AFG, Freeman SN, Pywell RF, Heard MS. Bumble bee species' responses to a targeted conservation measure depend on landscape context and habitat quality. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2011; 21:1760-71. [PMID: 21830716 DOI: 10.1890/10-0677.1] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The global decline of insect pollinators, especially bees, is cause for concern, and there is an urgent need for cost-effective conservation measures in agricultural landscapes. While landscape context and habitat quality are known to influence species richness and abundance of bees, there is a lack of evidence from manipulative field experiments on bees' responses to adaptive management across differently structured landscapes. We present the results of a large-scale study that investigated the effects of a targeted agri-environment scheme (AES) on bumble bees (Bombus spp.) over three years in the United Kingdom. Forage patches of different sizes were sown with a conservation flower mixture across eight sites covering a broad range of agricultural land use types. Species richness and worker densities (especially of the longer-tongued Bombus species for which the mixture was targeted) were significantly higher on sown forage patches than on existing non-crop control habitats throughout the three-year study, but the strength of this response depended on both the proportions of arable land and abundance of herbaceous forb species in the surrounding landscape. The size of sown patches also affected worker density, with smaller patches (0.25 ha) attracting higher densities of some species than larger patches (1.0 ha). Our models show that a targeted AES can deliver greater net benefits in more intensively farmed areas, in terms of the number and species richness of bumble bees supported, than in heterogeneous landscapes where other foraging habitats exist. These findings serve to strengthen the evidence base for extending agri-environment schemes to boost declining pollinator populations to a larger number of agricultural landscapes across the globe.
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Affiliation(s)
- C Carvell
- NERC Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
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40
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Affiliation(s)
- Tim Clutton-Brock
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
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41
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Bots J, Van Dongen S, De Bruyn L, Van Houtte N, Van Gossum H. Clutch size and reproductive success in a female polymorphic insect. Evol Ecol 2010. [DOI: 10.1007/s10682-010-9362-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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