Inheritance of malathion resistance in the parasitoid Anisopteromalus calandrae (Hymenoptera: Pteromalidae)

The genetic basis of malathion resistance in the Bamberg (R) strain of Anisopteromalus calandrae (Howard) was determined with reference to a susceptible (S) laboratory strain of the parasitoid. Evidence from bioassays of male and female progeny from the parent R and S strains, F1 hybrids, backcrosses, and inter se (self) crosses indicates that the malathion resistance in this haplo-diploid wasp is inherited as an incompletely dominant trait controlled by a single gene. This inheritance pattern will slow the diluting effect of interbreeding of progeny from released resistant wasps with susceptible wasps present in any resident population within a particular grain storage facility. It may also allow either an inoculative or inundative release strategy, depending on the size of the resident parasitoid population, within an integrated chemical-biological management program for grain weevils in stored cereals.