Development and functional response of Coelophora inaequalis (Coleoptera: Coccinellidae) feeding on brown citrus aphid, Toxoptera citricida (Homoptera: Aphididae)

1 Development and survivorship of Coelophora inaequalis (F.) were evaluated in the laboratory on the brown citrus aphid, Toxoptera citricida (Kirkaldy) at 20 and 25 degrees C. Coelophora inaequalis could complete its life cycle feeding on T. citricida at these two temperatures. The developmental period from egg to adult was significantly longer at 20 degrees C (24.7 d) than at 25 degrees C (15.9 d). The survivorship of combined immature stages were higher at 25 degrees C (39.2%) than at 20 degrees C (34.3%). 2 The effects of prey densities (4-64 aphids per leaf disk) on the functional responses of C. inaequalis fourth-instar larvae and female adults were investigated using grapefruit leaf disks over a 24-h period at 25 degrees C and a photoperiod of LD 14 : 10 h. Logistic regression analyses indicated that fourth-instar larvae and adults exhibited a type II functional response to aphid density. Fourth-instar larvae had a higher search rate (0.1305) than C. inaequalis female adults (0.0989). The handling time of fourth-instar larvae (30.4 min) was significantly longer than that of female adults (5.8 min). Collectively, C. inaequalis appears to be a promising biological control agent of T. citricida in the citrus groves.