Tiphodytes gerriphagus (Marchal)(Hymenoptera, Scelionidae), a swimming wasp new to Ireland

摘要

The world fauna of Tiphodytes (Hymenoptera: Scelionidae) was reviewed by Mineo et al. (2009). Two species definitely occur in Europe viz. T. gerriphagus (Marchal, 1900) and T. robertae Mineo, 1993. The status of a possible third species described by De-Stefani Perez (1902) is unknown. Only the biology of T gerriphagus has been studied. The species is known to be an egg parasitoid of waterstriders, the recorded hosts belonging to the genera Gerris, Limnoporus and Trepobates spp. (Hemiptera: Gerridae). Adults of Tiphodytes have been observed swimming quickly and strongly in the water (Hirashima et al. 1999) and species belonging to the genus have sclerotisation on the wing margins presumably to assist them while swimming in aquatic habitats (Figs la-d). However, T gerriphagus is known to use its wings equally well for flying in the air (Notton 2006). As Tiphodytes has not been recorded from Ireland, it was decided to search for the genus on the island.