Abstract:Seven spot ladybird,Coccinella septempunctata are beneficial to crop, because of their predacious habits. In recent years, the ladybirds have played an important role in the biological control of cotton aphids in China. In laboratory,the functional response of the larve and female adult of ladybird to aphid belongs to the type of Holling I .Ladybird has the largest attacking rate and smallest handling time at 28癈. Assuming thata. Prey population has a logistic growth.b. Predator searches for prey randomly, ...