Sex- and size-dependent variation in wing morphology of the cuckoo wasp Trichrysis cyanea (Hymenoptera: Chrysididae)

Abstract

http://www.eje.cz around 3000 described species. They parasitize sawfl ies, aculeate wasps and bees and in some cases also silk moths and stick insects (Kimsey & Bohart, 1990). So far, there are no reports of sexual dimorphism and/or intra-sexual variation in wing size and morphology of any chrysidid wasp. In the present study, we focus on one species of Chrysididae, Trichrysis cyanea (Linnaeus, 1758). This is a palearctic species and unlike many other cuckoo wasps, has a broad range of hymenopteran hosts, belonging mainly to Pompilidae (Trypoxylon) and Crabronidae (Auplopus and Deuteragenia) (Pauli et al., 2019; Wiesbauer et al., 2020). A recent study (Fröhlich et al., 2022) reports sexual dimorphism in cuticular hydrocarbons in T. cyanea. Furthermore, female T. cyanea express several markedly different profi les of cuticular hydrocarbons, the reason of which is still unclear, although adaptations (mimicry) to different host species or signalling of the females' reproductive status have been hypothesized.Here, using geometric morphometrics on photographs of forewings taken with the aid of a newly developed tool that can be used on type-material as it does not require the removal of wings from specimens, we studied intraspecifi c variation in wing morphology and size in T. cyanea from eastern Austria. These fi ndings are discussed in the context of the current state of knowledge of this species' biology.