Incipient speciation in the Anastrepha fraterculus cryptic species complex: reproductive compatibility between A. sp.1 aff. fraterculus and A. sp.3 aff. fraterculus |
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| Authors: | Alzira Kelly Passos Roriz Hilton F. Japyassú Iara Sordi Joachim‐Bravo |
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| Affiliation: | 1. Instituto de Biologia, Universidade Federal da Bahia, Salvador, Bahia, Brazil;2. School of Biology, University of St Andrews, St Andrews, Fife, UK |
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| Abstract: | Reproductive isolation among biological strains can be detected by analyzing reproductive barriers between populations. The Anastrepha fraterculus Wiedemann (Diptera: Tephritidae) cryptic species complex comprises eight morphotypes defined by morphometric characteristics. The present study analyzed the existence of pre‐ and post‐zygotic isolation among populations of A. sp.1 aff. fraterculus (A. sp.1) and A. sp.3 aff. fraterculus (A. sp.3) determined by tests of sexual compatibility, analyses of the temporal pattern of calling behavior, and the reproductive performance of the offspring of homotypic and heterotypic crosses. Pre‐zygotic tests indicated asymmetric matings with preferences for homotypic crosses. The A. sp.3 population demonstrated distinct characteristics, including low copulation percentages and a high proportion of homotypic copulations under crowded conditions. The females of the A. sp.1 population demonstrated lower copulation latency. The analyzed morphotypes demonstrated two peaks in pheromone emission activity, at the beginning and at the end of the morning and were differentiated in the abundance of males. The calling behavior of the hybrids between A. sp.1 male and A. sp.3 female crosses had an intermediate pattern compared to either parental type. Post‐zygotic compatibility tests indicated low viability of the cross between A. sp.3 males and A. sp.1 females. Pronounced asymmetries were found in the sex ratios of the offspring of heterotypic crosses, and only hybrids from A. sp.1 male vs. A. sp.3 female crosses produced descendants. The observed pre‐ and post‐zygotic incompatibilities reflect the probable occurrence of incipient speciation between A. sp.1 and A. sp.3. A more adequate taxonomic classification of this species complex that considers the distinct characteristics of each morphotype will be needed to improve environmentally wise control methods against this insect pest. |
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| Keywords: | fruit flies sterile insect technique
SIT
agricultural pest fruticulture allopatry sibling species Tephritidae Diptera |
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