Abstract

The egg parasitoid Trissolcus semistriatus Nees is one of the natural enemies of the sunn pest, Eurygaster integriceps Put., which is one of the most destructive pests of wheat in Turkey. This research was conducted to determine whether some plant species have an effect on the parasitism of T. semistriatus on E. integriceps eggs in the laboratory at 26 o C, 60% relative humidity and 16:8 photoperiod conditions. Wheat (Triticum vulgare), cow cockle (Vaccaria pyramidata var. grandiflora), bifora (Bifora radians), common vetch (Vicia sativa) and turnipweed (Rapistrum rugosum) were tested, because these plants were common in or near the cereal fields in Tekirdag and also hosts of some pentatomids which are secondary host of egg parasitoids. The parasitism rate of T. semistriatus on E. integriceps eggs was investigated in the presence and absence of plants. The highest parasitism rate was obtained from common vetch as 94.9 % while the lowest was 68.9 % on cow cockle and also ratio of emergence was lowest in cow cockle as 89.9 %. The presence of plants significantly influenced parasitism rate and adult emergence while development period of males and females were not affected from plants, for this reason it was though several plants appear to be slightly repellant.