Species recognition through wing interference patterns (WIPs) in Achrysocharoides Girault (Hymenoptera, Eulophidae) including two new species

Abstract

Wing interference patterns (WIPs) are shown to be an important tool for species recognition in the genus Achrysocharoides Girault (Hymenoptera: Eulophidae). This is demonstrated by combining information from two previously published papers, comprising two cases of cryptic species, and by new material including the description of two new species, Achrysocharoides maieri and Achrysocharoides serotinae from North America. The cryptic species were initially separated through their distinct male WIPs. Subsequent analyses of the external morphology uncovered additional morphological differences supporting the original findings through WIPs, and biological data further strengthened the identity of these species. The new species described here also differ in their WIPs but the WIPs are similar in both sexes. Thus they provide a strong link between male and female and demonstrate that WIPs can also be useful for species recognition when the sexes are otherwise difficult to associate. Both new species are from Connecticut, USA, and were reared from Phyllonorycter propinquinella (Braun) (Lepidoptera: Gracillariidae) on black cherry (Prunus serotina); Achrysocharoides maieri has also been reared from Ph. nr crataegella on pin cherry (Prunus pensylvanica). To facilitate the identification of the new species they are included in a previously published key to North American species of Achrysocharoides. As a supplement to colourful WIPs we also demonstrate that grey scale images of uncoated wings from scanning electron microscopy can be used for visualization of the thickness distribution pattern in wing membranes.

Preliminary study of wing interference patterns (WIPs) in some species of soft scale (Hemiptera, Sternorrhyncha, Coccoidea, Coccidae)

“…The method used for preparation of the wings was standardized, as suggested by Shevtsova and Hansson (2011), i.e. dry wings were horizontally arranged (with the magnification 2 or 3×) and, flattened between a glass slide and glass cover.…”

“…mainly in small insects. The colour patterns appear when wings are viewed against a dark background and show the uneven thickness of the wing membrane (Shevtsova 2012). The thickness of the composite chitinous membrane varies with the topography of the wing and the areas of different thickness reflect different interference colours that together produce a specific colour pattern, the WIP.…”

“…Taxon specific colour patterns depend also on pigmentation, venation, and hair placement. The optically refracted pattern is also stabilized by membrane corrugations and spherical cell structure (Shevtsova et al 2011). Observations of WIPs in many groups of Hymenoptera and Diptera suggest that species identification is enhanced if WIPs are added to the taxonomic characters (Shevtsova and Hansson 2011, Hansson 2011, Hansson and Shevtsova 2012).…”

Sexual selection on wing interference patterns in Drosophila melanogaster

“…The biological significance of WIPs as originally proposed by Shevtsova et al (9) has so far mainly received attention for their potential as diagnostic species identification traits in taxonomic and systematic studies (12)(13)(14). The possible role of WIPs as signaling traits at the intraspecific level where they might be targets of sexual selection (15)(16)(17) has only been hypothesized and has not been experimentally investigated.…”

Three cryptic species in Asecodes (Förster) (Hymenoptera, Eulophidae) parasitizing larvae of Galerucella spp. (Coleoptera, Chrysomelidae), including a new species

“…Photos were taken at different focus levels and Helicon Focus Pro version 4.75 was used to merge them into a single image. The photography of wing interference patterns is described in detail by Shevtsova and Hansson (2011). The SEM photos were made from uncoated specimens on their original cardboard mounts.…”