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Díaz SS, Carisio L, Manino A, Biella P, Porporato M. Nesting, Sex Ratio and Natural Enemies of the Giant Resin Bee in Relation to Native Species in Europe. INSECTS 2021; 12:545. [PMID: 34208066 PMCID: PMC8230627 DOI: 10.3390/insects12060545] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 11/16/2022]
Abstract
Megachile sculpturalis (Smith, 1853) is the first exotic bee species in Europe. Its remarkably fast expansion across this continent is leading to a growing concern on the extent of negative impacts to the native fauna. To evaluate the interactions of exotic bees with local wild bees, we set up trap nests for above-ground nesting bees on a semi-urban area of north-western Italy. We aimed to investigate the interaction in artificial traps between the exotic and native wild bees and to assess offspring traits accounting for exotic bee fitness: progeny sex ratio and incidence of natural enemies. We found that the tunnels occupied by exotic bees were already cohabited by O. cornuta, and thus the cells of later nesting alien bees may block the native bee emergence for the next year. The progeny sex ratio of M. sculpturalis was strongly unbalanced toward males, indicating a temporary adverse population trend in the local invaded area. In addition, we documented the presence of three native natural enemies affecting the brood of the exotic bee. Our results bring out new insights on how the M. sculpturalis indirectly competes with native species and on its performance in new locations.
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Affiliation(s)
- Sara Straffon Díaz
- Department of Agricultural Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco (Turin), Italy; (L.C.); (A.M.); (M.P.)
| | - Luca Carisio
- Department of Agricultural Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco (Turin), Italy; (L.C.); (A.M.); (M.P.)
| | - Aulo Manino
- Department of Agricultural Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco (Turin), Italy; (L.C.); (A.M.); (M.P.)
| | - Paolo Biella
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy;
| | - Marco Porporato
- Department of Agricultural Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco (Turin), Italy; (L.C.); (A.M.); (M.P.)
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Collet M, Amat I, Sauzet S, Auguste A, Fauvergue X, Mouton L, Desouhant E. Insects and incest: Sib-mating tolerance in natural populations of a parasitoid wasp. Mol Ecol 2020; 29:596-609. [PMID: 31850599 DOI: 10.1111/mec.15340] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 12/11/2019] [Accepted: 12/12/2019] [Indexed: 11/29/2022]
Abstract
Sib-mating avoidance is a pervasive behaviour that is expected to evolve in species subject to inbreeding depression. Although laboratory studies provide elegant demonstrations, small-scaled bioassays minimize the costs of mate finding and choice, and thus may produce spurious findings. We therefore combined laboratory experiments with field observations to examine the existence of inbreeding avoidance using the parasitoid wasp Venturia canescens. In the laboratory, our approach consisted of mate-choice experiments to assess kin discrimination in population cages with competitive interactions. A higher mating probability after sib rejections suggested that females could discriminate their sibs; however, in contrast to previous findings, sib-mating avoidance was not observed. To compare our laboratory results to field data, we captured 241 individuals from two populations. Females laid eggs in the lab, and 226 daughters were obtained. All individuals were genotyped at 18 microsatellite loci, which allowed inference of the genotype of each female's mate and subsequently the relatedness within each mating pair. We found that the observed rate of sib-mating did not differ from the probability that sibs encountered one another at random in the field, which is consistent with an absence of sib-mating avoidance. In addition, we detected a weak but significant male-biased dispersal, which could reduce encounters between sibs. We also found weak fitness costs associated with sib-mating. As such, the sex-biased dispersal that we found is probably sufficient to mitigate these costs. These results imply that kin discrimination has probably evolved for purposes other than mate choice, such as superparasitism avoidance.
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Affiliation(s)
- Marie Collet
- Laboratoire de Biométrie et Biologie Evolutive UMR5558, CNRS, Université Lyon 1, Univ Lyon, Villeurbanne, France
| | - Isabelle Amat
- Laboratoire de Biométrie et Biologie Evolutive UMR5558, CNRS, Université Lyon 1, Univ Lyon, Villeurbanne, France
| | - Sandrine Sauzet
- Laboratoire de Biométrie et Biologie Evolutive UMR5558, CNRS, Université Lyon 1, Univ Lyon, Villeurbanne, France
| | | | | | - Laurence Mouton
- Laboratoire de Biométrie et Biologie Evolutive UMR5558, CNRS, Université Lyon 1, Univ Lyon, Villeurbanne, France
| | - Emmanuel Desouhant
- Laboratoire de Biométrie et Biologie Evolutive UMR5558, CNRS, Université Lyon 1, Univ Lyon, Villeurbanne, France
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Queffelec J, Wooding AL, Greeff JM, Garnas JR, Hurley BP, Wingfield MJ, Slippers B. Mechanisms that influence sex ratio variation in the invasive hymenopteran Sirex noctilio in South Africa. Ecol Evol 2019; 9:7966-7973. [PMID: 31380064 PMCID: PMC6662311 DOI: 10.1002/ece3.5305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/11/2019] [Accepted: 03/29/2019] [Indexed: 11/15/2022] Open
Abstract
Sirex noctilio is an economically important invasive pest of commercial pine forestry in the Southern Hemisphere. Newly established invasive populations of this woodwasp are characterized by highly male-biased sex ratios that subsequently revert to those seen in the native range. This trend was not observed in the population of S. noctilio from the summer rainfall regions in South Africa, which remained highly male-biased for almost a decade. The aim of this study was to determine the cause of this persistent male bias. As an explanation for this pattern, we test hypotheses related to mating success, female investment in male versus female offspring, and genetic diversity affecting diploid male production due to complementary sex determination. We found that 61% of females in a newly established S. noctilio population were mated. Microsatellite data analysis showed that populations of S. noctilio from the summer rainfall regions in South Africa are far less genetically diverse than those from the winter rainfall region, with mean Nei's unbiased gene diversity indexes of 0.056 and 0.273, respectively. These data also identified diploid males at low frequencies in both the winter (5%) and summer (2%) rainfall regions. The results suggest the presence of a complementary sex determination mechanism in S. noctilio, but imply that reduced genetic diversity is not the main driver of the male bias observed in the summer rainfall region. Among all the factors considered, selective investment in sons appears to have the most significant influence on male bias in S. noctilio populations. Why this investment remains different in frontier or early invasive populations is not clear but could be influenced by females laying unfertilized eggs to avoid diploid male production in populations with a high genetic relatedness.
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Affiliation(s)
- Joséphine Queffelec
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoriaSouth Africa
| | - Amy L. Wooding
- Department of Biochemistry, Genetics and MicrobiologyUniversity of PretoriaPretoriaSouth Africa
| | - Jaco M. Greeff
- Department of Biochemistry, Genetics and MicrobiologyUniversity of PretoriaPretoriaSouth Africa
| | - Jeffrey R. Garnas
- Department of Natural Resources and the EnvironmentUniversity of New HampshireDurhamNew Hampshire
- Department of Zoology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoriaSouth Africa
| | - Brett P. Hurley
- Department of Zoology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoriaSouth Africa
| | - Michael J. Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoriaSouth Africa
- Department of Zoology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoriaSouth Africa
| | - Bernard Slippers
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoriaSouth Africa
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Nair A, Nonaka E, van Nouhuys S. Increased fluctuation in a butterfly metapopulation leads to diploid males and decline of a hyperparasitoid. Proc Biol Sci 2018; 285:rspb.2018.0372. [PMID: 30135149 PMCID: PMC6125898 DOI: 10.1098/rspb.2018.0372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 07/20/2018] [Indexed: 12/14/2022] Open
Abstract
Climate change can increase spatial synchrony of population dynamics, leading to large-scale fluctuation that destabilizes communities. High trophic level species such as parasitoids are disproportionally affected because they depend on unstable resources. Most parasitoid wasps have complementary sex determination, producing sterile males when inbred, which can theoretically lead to population extinction via the diploid male vortex (DMV). We examined this process empirically using a hyperparasitoid population inhabiting a spatially structured host population in a large fragmented landscape. Over four years of high host butterfly metapopulation fluctuation, diploid male production by the wasp increased, and effective population size declined precipitously. Our multitrophic spatially structured model shows that host population fluctuation can cause local extinctions of the hyperparasitoid because of the DMV. However, regionally it persists because spatial structure allows for efficient local genetic rescue via balancing selection for rare alleles carried by immigrants. This is, to our knowledge, the first empirically based study of the possibility of the DMV in a natural host–parasitoid system.
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Affiliation(s)
- Abhilash Nair
- Metapopulation Research Centre, Department of Biosciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland
| | - Etsuko Nonaka
- Metapopulation Research Centre, Department of Biosciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland.,Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 114 18, Sweden
| | - Saskya van Nouhuys
- Metapopulation Research Centre, Department of Biosciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland .,Department of Entomology, Cornell University, Ithaca, NY 14853, USA
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