EFFECTS OF THE INSECT GROWTH REGULATOR FENOXYCARB ON IMMATURE CHRYSOPERLA RUFILABRIS (NEUROPTERA: CHRYSOPIDAE)

Abstract

Fenoxycarb (Comply®), a juvenile hormone analog, was tested in the laboratory at three concentrations (0.1, 1.0 and 10.0 mg [AI]/l) for toxicity to eggs, three larval instars and pupae of Chrysoperla rufilabris (Burmeister). Significant effects of fenoxycarb on all immature stages of C. rufilabris were found and the degree of effects depends on the stages treated and the concentrations used. Fenoxycarb showed significant ovicidal effect on C. rufilabris eggs, with 66.7, 76.6 and 86.7% survival rates at 0.1, 1.0 and 10.0 mg (AI)/l, respectively. Lethal effects on larvae varied greatly with high survival rates when the larvae were treated in the first and second instars (76.7-86.7% and 90.0-93.3%, respectively), and low survival rates (6.7-16.7%) when third instars were treated. Mortality at the pupal stage ranged from 90.0 to 93.3%. Fenoxycarb significantly delayed the developmental times from the stage treated to adult emergence for all immatures of C. rufilabris that successfully developed to adults by 3.2-4.6, 2.3-3.0, 2.1-2.8, and 4.6-7.5 days when egg, first, second and third instars were treated, respectively, compared with water treated control. When treated as pupae, fenoxycarb had no significant effects on pupal development. Among the three larval stages, the third instar is the most susceptible and vulnerable stage. The compatibility of fenoxycarb in integrated pest management programs is discussed.