DISPERSAL CAPABILITY OF THE EGG PARASITOID TRICHOGRAMMA PRINCIPIUM ON TOMATO IN PLASTIC HOUSE AND ITS PARASITISM EFFICIENCY ON THE COTTON LEAFWORM EGGS

Abstract

Results of field experiments which carried out at the College of Agriculture/ University of Baghdad, Abu Ghraib revealed, that movement activity of parasitoid Trichogramma principium gradually decreased. The peak of parasitoid activity was on the fourth day after release in the plastic house cultivated with tomatoes. Mean of captured individuals at the distance of 7 m. for all days attained 4.048 individuals/ trap, followed by 9 m. with mean of 2,238 individuals/ trap. The mean of captured individuals attained 5.667 individuals/ trap at 7 m from release point, which was superior on the rest distances. Mean of captured individuals for colours, at the high of 50 and 100 cm from soil surface, was gradually increased until reached the peak at the 5th day. Colour traps that attract parasitoids can be arranged increasingly as yellow, blue, white and green. Results showed that the number of cotton leafworm larvae per plant in release treatment was 0.39 larvae/ plant, which was significantly depressed on that of non-release treatment (2.76 larvae/ plant). The number of egg masses which attained 0.11, 0.04 masses/ plant for control and treatment respectively, results showed no significantly deference between them. High parasitism percentage on live eggs of cotton leafworm attained 54.68% at 2 m from release point, this result significantly exceeded on distances of 4, 6, 8 and 10 m.