MALE INSECT-PARASITIC NEMATODES - A COLONIZING SEX

An adaptive strategy enhancing reproductive success is described for p arasitic nematodes. Male infective juveniles of insect-parasitic nemat odes, Steinernema spp. (Rhabditida: Steinernematidae) are dispersers, and take greater risks than females during the host-finding phase of p arasitism. They disperse, locate, and establish in distant live hosts before females. Parasitism by male infective juveniles renders the inf ected hosts suitable for nematode development, and more attractive to female infective juveniles. Such 'recruitment' may be a strategy to pr otect the nematodes against uncertainties of mate finding, thereby enh ancing reproductive success.