Factors affecting larval cannibalism in the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

AbstractCannibalism is a common phenomenon in insects including the cotton bollworm, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae). The purpose of the present study was to investigate how factors (food availability, temperature and larval development stage) affect cannibalistic tendency in H. armigera under laboratory conditions. The results showed that cannibalism frequency of third instars reared on artificial diets was remarkably lower than that without artificial diets. The mortality was 90.00, 41.67, 38.33, 28.33 and 35.00%, as the amount of 0.00, 0.25, 0.50, 0.75 and 0.10 g/larva of artificial diets at 56 h of post-treatment, respectively. No significant difference in mortality was observed between treatment of 0.25, 0.50 and 1.00 g/larva of artificial diets. Cannibalistic behaviour was obviously observed when third instars in groups were housed at four different temperatures including 22, 25, 28 and 31 °C. The mortality of third instars enhanced greatly as the rearing temperature increased...