Responses of Tersilochus microgaster and Tersilochus obscurator (Hymenoptera: Ichneumonidae) to volatile 2-phenylethyl-isothiocyanate

摘要

The ichneumonids Tersilochus microgaster and T. obscurator are univoltine, solitary, koinobiontic endoparasitoids of the cabbage stem flea beetle (Psylliodes chrysocephala) and cabbage stem weevil (Ceutorhynchus pallidactylus), respectively. They parasitise the larvae of their hosts in petioles and stems. As do their hosts, they migrate into the rape crop from their overwintering sites each spring (Ulber, 2003; Ulber & Williams, 2003). Semiochemicals released by rape plants (e.g. isothiocyanates) canattract pests and parasitoids (Murchie et al., 1997; Jonsson et al., 2005). The effect of 2-phenylethylisothiocyanate on the capture of T. microgaster and T. obscurator was studied in a series of field experiments.