Demonstration of Host Discrimination in the Parasite Orgilus lepidus (Hymenoptera: Braconidae)

Both mated and virgin females of the braconid wasp Orgilus lepidus Muesebeck, a solitary endoparasite of the potato tuberworm, Phthorimaca operculella (Zeller), avoided already-parasitized host larvae. Host discrimination was evidenced by the nonrandom distribution of eggs among a number of initially healthy hosts and by a marked preference for healthy hosts exposed together with hosts parasitized earlier by conspecific females.