THE STUDY EFFECT OF THE PREY DENSITY OF GREAT IMPACT ON LIFE CYCLE OF GREEN LACEWING

Abstract

A research was conducted at the Biological control Unit, College of Agriculture in Abu-Ghraib to show the effect the Prey density of Aphis fabae had great impact on life cycle of the predator green lacewing Chrysoperla carnea) Stephens.( The results of study also showed that the Prey density of Aphis fabae had great impact on life cycle of green lacewing C.carnea, the developmental time C.carnea larvae were 16.7, 12.6 and 9.7 days at prey densities 15, 30 and 45. The survival rates was also influenced by prey density ,the larvae mortality 50% at density 15 and 20% at 45 when reared at 25 ± 2C. The results of study showed that the predator increased the attack rat with increasing prey density .The larvae consumed 9.35, 16.57 and 22.06 nymph of aphid at the densities of 15, 30 and 45 nymph of aphid during their development. The developmental time of pupae was also influenced by prey density. It was 16.16, 12.66 and 9.66 days at densities of 15, 30 and 45 nymph of aphid respectively at temperature 25 ± 2C and relative humidity of 60 ± 5.