Apoptosis of Spodoptera litura larval hemocytes induced by heavy metal zinc

By adding different amount of zinc into the artificial medium of the insect larvae, the zinc-induced apoptosis of the larvae haemocytes of the herbivorous insectSpodoptera litura Fabricius was investigated with flow cytometer. The results showed that the increase of zinc dose in the artificial feed led to the accumulations of zinc in the larval hemolymph and fat body, and more zinc was accumulated in fat body than in hemolymph. The apoptosis of hemocytes was significantly induced at high zinc concentration (1000 mg·kg−1) in the insect diet, and the apoptosis rate was 63.63%, which was remarkably higher than that at control and lower concentrations (50-500 mg·kg−1). This suggests that the high dose of zinc in the artificial diet ofS. litura larvae could induce the apoptosis of the larval hemocytes ofS. litura.