Tetrastiches brachyopae (Hymenoptera: Eulophidae) new to the Netherlands, reared from Brachyopa larvae (Diptera: Syrphidae)

摘要

Tetrastichus brachyopae is reported as new to the Netherlands from De Kaaistoep, a nature reserve close to the city of Tilburg (province of Noord-Brabant) and not far from the Belgium border. This eulophid wasp is exclusively known as natural enemy ofhoverflies of the genus Brachyopa. The hoverfly larvae develop in sap runs, mostly of various decidious tree species. The wasps were bred from the puparia which were obtained as larvae from an oak. Both B. bicolor and B. insensilis were found as hosts.Tetrastichus brachyopae is a gregarious koinobiont endoparasitoid, with clutch sizes varying from 7-18 individuals per host. The emergence sex ratios show a strong female bias, indicating local mate competition, where brothers compete over a limited number of mates, increasing parental fitness if more daughters are produced.