Effect of Azadirachtin on Growth and Development of Spodoptera litura

Effects of Azadirachtin on the growth and development of the 3rd-instar larvae of Spodoptera litura F.by feeding on soaked Brassica oleracea leaf and artificial diet and topical application were studied.The results showed that Azadirachtin had significant inhibition to the development of 3rd-instar larvae of Spodoptera litura,the higher the concentration of Azadirachtin,the lower the times of body weight increase and the higher the mortality of the larvae was.After treating larvae with soaked Brassica oleracea leaf and artifical diet,the survival duration of the larvae ranged 12~14 days and the lethal effect reached 100% under each concentration treatment.In addition,by the topical application,the lethal effect of Azadirachtin changed more significantly as the time increased,and the highest lethal effect was 92.86%.