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 °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 °C (24.7 d) than at 25 °C (15.9 d). The survivorship of combined immature stages were higher at 25 °C (39.2%) than at 20 °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 °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.
Document Type: Research Article
Affiliations: Fort Lauderdale Research and Education Center, IFAS, University of Florida, 3205 College Avenue, Fort Lauderdale, FL 33314, U.S.A.
Publication date: February 1, 2001