Study of feeding rate of Cryptolaemus montrouzieri on eggs of the citrus cushions and citrus mealybug and its larval developmental period

The ladybird predator, Cryptolaemus montrouzieri is one of the most important predators of scale insects which in different larval instars and adult stage feed on eggs of the citrus cushions, Pulvinaria aurantii and the citrus mealybug, Planococcus citri in northern Iran. In this study, The feeding rate of different age stages of the predator including first, second, third and fourth larvae and adult stage (male and female) were calculated on the eggs of two pests at 20, 25, 30 and 35oC, 80± 5% RH and 16L:8D h photoperiods. Also, different developmental periods of larvae were calculated. Results of mean comparison showed that there is a significant difference between the different age stages and in different temperatures. So that the highest feeding rate observed by adult ladybird on the eggs of P. aurantii (5762.4 ± 503.22) and P. citri (2222.15 ± 313.79), respectively. Among different temperatures, the highest feeding rate from the citrus cushions, P. aurantii was observed at 30°C (3696.33 ± 240.19) and from the citrus mealybug, P. citri (1265.06 ± 139.26) at 25°C, respectively. The lowest larval period was observed at 25°C. Results showed that feeding rate of the predator on eggs of the pest is high and can be used to pest control in orchards and replaced with chemical pesticides.