Activities of four insect growth regulator formulations of fenoxycarb against Psorophora columbiae larvae.

Four formulations of fenoxycarb were evaluated at dosages of 0.022 and 0.011 kg ai/ha against Psorophora columbiae larvae in rice plots. Granular formulations, at both rates, provided moderate to excellent control of larvae introduced within 24 h posttreatment. A 1.0% fenoxycarb/200 ITU B.t.i. granule provided 86.2% reduction of emergence from larvae introduced at 120 h posttreatment. Aside from this formulation residual activity was lacking. The liquid formulation performed moderately well at the high rate against larvae introduced within 24 h; however, residual activity rapidly diminished.