A NEMATODE (<i>DELADENUS</i> SP.: NEOTYLENCHIDAE) ASSOCIATED WITH <i>RHYSSA</i> SPP. (HYMENOPTERA: ICHNEUMONIDAE), PARASITES OF SIRICID WOODWASPS

Abstract In 1965 nematodes were recorded from three species of Rhyssa in shipments received from India and Europe. The nematodes from European Rhyssa spp. are now known to be Deladenus sp. The growth and reproduction of the nematodes reduces the fecundity and longevity of their hosts. Many of the larval nematodes invade the reproductive system in female hosts, and transfer of the nematodes probably occurs during probing by infested females. The pathological effects of this nematode on both sexes of the host are described. Since the siricid woodwasps, the host of Rhyssa , are also subject to infestation by nematodes, a comparison is made between characteristic symptoms in both insects.