Biological aspects and predatory capacity of Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) fed Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae)

Abstract: In the citrus mealybug complex, Planococcus citri is one of the most important pests and its control is affected by insecticides. The green lacewing Chrysoperla externa is an insect often found in citrus orchards and is a natural predator of this pest. This work deals with studies on the predatory capacity and some biological aspects of larvae fed the three instars and adult female of P. citri. The experiments were conducted at 25±1°C, 70±10% of RH and 12-hour photophase with four treatments, represented by the development stages, and 30 replicates in a complete randomized design. It was found that the total predatory capacity of lacewing larvae was 231.2; 77.9; 32.6 and 21.2 for the three instars and adult females, respectively. The longevity of second and third instars of green lacewing larvae was lengthened when fed on adult mealybug females. The pupal stage was longer when it originated from larvae fed second and third instar larvae and adult females. The immature stage lasted from 19.8 to 22.9 days, and survivorship for this period was from 78.0 to 91.0%. A reduction in the number of consumed mealybugs was found in each instar, regardless the lacewing instar, however both nymphs and adult mealybug females were adequate prey for the larval development of C. externa.