INTRASPECIFIC HYPERPARASITISM IN A PRIMARY HYMENOPTERAN PARASITOID

In solitary parasitoids, in which only one individual can emerge per h ost, the adaptive value of conspecific superparasitism is a function o f the survival probability of the egg laid by the superparasitizing fe male. In the few cases which these probabilities are compared, the old est immature has an advantage over the other individuals. We measured the acceptance rate of parasitized hosts and survival rate of supernum erary larvae in Anaphes victus (Hymenoptera: Mymaridae) in relation to the interval between ovipositions. When this interval was 5-7 days, t he first immature was at the prepupa and pupa stage respectively, and female Anaphes victus changed their oviposition behavior markedly. The y killed the developing parasitoid of their own species before oviposi ting in it. The progeny of these females, which are normally primary p arasitoids, developed thereafter as hyperparasitoids. Indeed, in contr ast with other species, the survival of the second female's progeny in creased with the time interval between ovipositions. This type of facu ltative intraspecific hyperparasitism is different from autoparasitism in Aphelinidae and has never been mentioned in other parasitoids; it would be adaptive if females of this short-lived species encounter low -quality patches.