The Afrotropical breeding grounds of the Palearctic-African migratory painted lady butterflies (Vanessa cardui)

Migratory insects are key players in ecosystem functioning and services, but their spatiotemporal distributions are typically poorly known. Ecological niche modeling (ENM) may be used to predict species seasonal distributions, but the resulting hypotheses should eventually be validated by field data. The painted lady butterfly (Vanessa cardui) performs multigenerational migrations between Europe and Africa and has become a model species for insect movement ecology. While the annual migration cycle of this species is well understood for Europe and northernmost Africa, it is still unknown where most individuals spend the winter. Through ENM, we previously predicted suitable breeding grounds in the subhumid regions near the tropics between November and February. In this work, we assess the suitability of these predictions through i) extensive field surveys and ii) two-year monitoring in six countries: a large-scale monitoring scheme to study butterfly migration in Africa. We document new breeding locations, year-round phenological information, and hostplant use. Field observations were nearly always predicted with high probability by the previous ENM, and monitoring demonstrated the influence of the precipitation seasonality regime on migratory phenology. Using the updated dataset, we built a refined ENM for the Palearctic-African range of V. cardui. We confirm the relevance of the Afrotropical region and document the missing natural history pieces of the longest migratory cycle described in butterflies.This work was funded by the National Geographic Society (grant WW1-300R-18); by the British Ecological Society (grant LRB16/1015); by the Research and Conservation Projects of the Fundació Barcelona Zoo; by the grant PID2020-117739GA-I00/MCIN/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation and the Spanish State Research Agency to G.T.; by the grant LINKA20399 from the Spanish National Research Council iLink program to G.T., C.P.B., N.E.P., and R.V.; by fellowship FPU19/01593 of the program Formación de Profesorado Universitario (FPU) to A.G.-B.; by the Turkana Basin Institute, National Geographic Society, and Whitley Fund for Nature to D.J.M.; and by grant 2018-00738 of the New Frontiers in Research Fund (Government of Canada) to G.T. and C.P.B.Significance Abstract Results Field Surveys, Larval Hostplants, and Field-Based Model Validation Monitoring Results and Population Dynamics across Regions A Refined Model for the Afrotropical Region Discussion The Afrotropical Breeding Grounds of V. cardui: Multiple Generations Shift South Toward the Tropics Diversity and Phenology of Larval Hostplants in the Afrotropics The Ecological Relevance of Delimiting Spatiotemporal Distributions in Migratory Insects Conclusion Methods December-January Field Surveys and Year-Round Monitoring Spatiotemporal Ecological Niche Modeling Data, Materials, and Software Availability Acknowledgments Supporting Information Reference

Entomofaune chalcidienne de Ficus sycomorus L. : répartition et abondance dans différentes zones climatiques du Sénégal (Hymenoptera, Chalcidoidea)

Correspondance: [email protected] audienceChalcid Wasps associated with Ficus sycomorus L. have never been subject of a study in Senegal despite their importance. Several species of Hymenoptera interact inside the figs of F. sycomorus whose Ceratosolen arabicus Mayr assures its pollination. This study, led in three climatic domains in Senegal, permited to identify eight species of Chalcid Wasps; we also noticed that fragmentation of the environment of F. sycomorus does not strongly influences the distribution of C. arabicus. However, it seems that the negative impact of Sycophaga sycomori (L.), but especially of Apocrypta longitarsus Mayr on the pollinator of F. sycomorus in Senegal, may be worrying.Les Chalcidiens (Hymenoptera, Chalcidoidea) associés à Ficus sycomorus L. n'ont jamais fait l'objet d'une étude au Sénégal malgré leur importance. Plusieurs espèces d'Hyménoptères interagissent à l'intérieur des figues de F. sycomorus dont Ceratosolen arabicus Mayr qui assure sa pollinisation. Cette étude menée dans trois domaines climatiques au Sénégal a permis d'identifier huit espèces de Chalcidiens ; nous avons aussi noté que la fragmentation de l'habitat de F. sycomorus influe peu sur la répartition de C. arabicus. Cependant, il convient de soulever des inquiétudes concertant l'impact négatif qu'exerce Sycophaga sycomori (L.) mais surtout Apocrypta longitarsus Mayr sur le pollinisateur de F. sycomorus au Sénégal

Diversification, selective sweep, and body size in the invasive Palearctic alfalfa weevil infected with Wolbachia

International audienceThe alfalfa weevil Hypera postica , native to the Western Palearctic, is an invasive legume pest with two divergent mitochondrial clades in its invading regions, the Western clade and the Eastern/Egyptian clade. However, knowledge regarding the native populations is limited. The Western clade is infected with the endosymbiotic bacteria Wolbachia that cause cytoplasmic incompatibility in host weevils. Our aim was to elucidate the spatial genetic structure of this insect and the effect of Wolbachia on its population diversity. We analyzed two mitochondrial and two nuclear genes of the weevil from its native ranges. The Western clade was distributed in western/central Europe, whereas the Eastern/Egyptian clade was distributed from the Mediterranean basin to central Asia. Intermediate mitotypes were found from the Balkans to central Asia. Most Western clade individuals in western Europe were infected with an identical Wolbachia strain. Mitochondrial genetic diversity of the infected individuals was minimal. The infected clades demonstrated a higher nonsynonymous/synonymous substitution rate ratio than the uninfected clades, suggesting a higher fixation of nonsynonymous mutations due to a selective sweep by Wolbachia . Trans-Mediterranean and within-European dispersal routes were supported. We suggest that the ancestral populations diversified by geographic isolation due to glaciations and that the diversity was reduced in the west by a recent Wolbachia -driven sweep(s). The intermediate clade exhibited a body size and host plant that differed from the other clades. Pros and cons of the possible use of infected-clade males to control uninfected populations are discussed