EFFECTS OF COLD SHOCK ON HOST EGGS PARASITIZATION BY TRICHOGRAMMA BUESI VOEGELE (HYMENOPTERA, TRICHOGRAMMATIDAE) FEMALES]
Effects of the cold shock (4 °C during 18—24 h) on survival of Trichogramma buesi females, on their fecundity, and on the inclination to parasitize the grain moth eggs were studied in laboratory conditions. The cold shock did not result in any significant change in the survival, although the proportion of females that parasitized the grain moth eggs and the fecundity of these females slightly decreased. However, females that have already started parasitization before the cold shock parasitized the grain moth eggs much more often than females that did not parasitize earlier. In most of the studied insect species, cold shock resulted in a sharp decrease or even in a disruption of the effect of experience on the subsequent behaviour. Thus, the results of this study suggest that «the effect of acquired experience» (a tendency to continue parasitization of a given host species) in Trichogramma females is based not on learning (or not only on learning) but rather on different, possibly on hormonal mechanisms.