Comparative life history and fecundity of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) on different soybean varieties

The effect of different soybean varieties (Glycine max 356, M4, M7, M9, Clark, Sahar, JK, BP, Williams, L17, Zane, Gorgan3 and DPX) on the life history and fecundity of the gram pod borer Helicoverpa armigera (Hubner) (synonym Heliothis armigera (Hubner), also known as the American or African bollworm) was determined at 25 +/- 1 degrees C, 65 +/- 5% r.h. and a light : dark cycle of 16:8 h. The larval period ranged 17.30 to 26.20 days on M7 and L17, respectively. The longest development time was on L17, BP and Sahar (42.71, 40.29 and 39.20 days, respectively) and the shortest was on M7, M9, Williams and Clark (34.21, 36.06, 36.60 and 36.82 days, respectively). The development index of overall immature stages varied from 1.39 to 2.41, with the minimum on L17 and BP and the maximum on M7. The highest daily fecundity and total fecundity (118.92 and 582.70 eggs, respectively) and the lowest (37.88 and 177.10 eggs, respectively) were observed on DPX and 356, respectively. Cluster analysis of the biological parameters of H. armigera on different soybean varieties demonstrated that BP, Sahar and L17 were partially resistant to H. armigera. Knowledge of the extent of susceptibility or resistance of crop varieties and biology of a pest on that crop are fundamental components of integrated pest management (IPM) programs for many crops. Such information can help to detect and monitor pest infestation, variety selection and crop breeding.