Brachyptery Analysis in Alloxysta (Hymenoptera: Figitidae): Synonymy of A. curta Ferrer-Suay and Pujade Villar as the Brachypterous Male of A. ramulifera (Thomson) in the Nearctic

Abstract

Eight brachypterous species have been described within the hymenopteran genus Alloxysta. Intraspecific wing polymorphism linked to sex has been previously hypothesized within this genus and the aim of this work was to confirm whether the phylogenetic relationships based on morphological characters between brachypterous and macropterous species are correct using molecular analyses. This study used material collected from Minnesota (USA), with 278 specimens identified as Alloxysta brachyptera (Hartig, 1840), A. curta Ferrer-Suay and Pujade-Villar, 2017 (Ferrer-suay et al. 2017), A. brevis (Thomson, 1862), or A. ramulifera (Thomson, 1862). Twenty-three of these specimens were subjected to sequencing of the barcoding gene, Cytochrome Oxidase I. Previous analyses had identified A. curta as a distinct species from A. ramulifera based in part on shorter wing length and our current sampling from Minnesota identified only male A. curta. However, our molecular analyses (COI) showed that A. curta should instead be considered a phenotypic variant of A. ramulifera exhibiting male brachyptery, and we establish this new synonymy here. Alloxysta brevis and A. brachyptera remain as valid species. These results suggest that some brachypterous taxa within the figitid subfamily Charipinae, which have been described as valid species, are actually sexually dimorphic forms from the same species with different wing morphology.