Effect of host diet on acceptance of eastern spruce budworm eggs byTrichogramma minutum

The acceptance behaviour of the parasitic wasp, Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae), was studied on two types of egg masses of eastern spruce budworm (SBW), Choristoneura fumiferana Clemens. Host eggs were obtained from moths that had been fed balsam fir or artificial diet during their larval stages. Parasitoids were reared from both types of hosts. Host acceptance assays were conducted where females were provided with a single egg mass and with a choice between egg masses. Regardless of the parasitoid's rearing host, females parasitised hosts reared from artificial diet more often than those from balsam fir. Response was consistent in both no-choice and choice assays. Rejection of hosts tended to occur during the examining stage of behaviour, suggesting that acceptability is judged externally. If a host was accepted, the same number of eggs were laid per egg mass regardless of treatment.