Parasitism of Trichogramma evanescens (Hym.: Trichogrammatidae) reared on different egg ages of Anagasta kuehniella (Lep.: Pyralidae)

Trichogramma evanescens Westwood is an important biological control agent of lepidopteran pests and is widely distributed throughout Iran. In the current study, parasitism rate of T. evenescens on different egg ages of the Anagasta= Ephestia kuehniella Zeller (1, 2, 3 and 4- day- old) was studied at 25±1ºC, 55±5% RH and 16: 8 h L: D photoperiod. The results obtained showed a significant effect on parasitism rate. The highest and the lowest values of net parasitism rate (C0) were 67.69 hosts and 15.92 hosts for 1 and 4- day- old eggs, respectively. The transformation rate of host population to parasitoid offspring (Qp < /sub>) was equal to 1 at all egg ages. The values of stable parasitism rate (ψ) decreased from 0.412 to 0.266 (host/parasitoid) with increasing host age from 1 to 4 day. Finite parasitism rate (was significantly affected by different egg ages and the highest (0.583 day-1) and lowest (0.337 day-1) values were recorded for 1 and 4- days- old eggs, respectively. The results of the current study indicated that parasitism of T. evanescens was strongly affected by different egg ages of A. kuehniella. This finding provide helpful information for mass rearing of T. evanescens.