Original Contribution SIDE EFFECTS OF IMIDACLOPRID AND ABAMECTIN ON THE MEALYBUG DESTROYER, CRYPTOLAEMUS MONTROUZIERI

The effect of sublethal concentration (LC50) of the imidacloprid and abamectin on Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), an efficient predator of the citrus mealybug, were tested under laboratory conditions. The toxicities of the insecticides were assayed using the topical application method and the LC50 value was determined based on a dose–response analysis. The LC50 values of female, for imidacloprid and abamectin were estimated to be 23.9 and 66.7 µg a.i./ml, respectively. Laboratory exposure of new emerged females to an LC50 level of imidacloprid and abamectin, caused significant decreases in adult female longevity, egg production and oviposition periods of surviving beetles. Population increase parameters were also adversely affected by insecticides application. Life table assays revealed that imidacloprid and abamectin caused significant reduction in the intrinsic rate of natural increase (rm value). The results showed little compatibility between C. montrouzieri and the use of imidacloprid and abamectin.