ACUTE EFFECTS OF PERMANONE(R)-31-66 (PERMETHRIN-PIPERONYL BUTOXIDE) ON NONTARGET MINNOWS AND GRASS SHRIMP

Immature sheepshead minnows (Cyprinodon variegatus), inland silverside s (Menidia beryllina), mosquitofish (Gambusia holbrooki), and grass sh rimp (Palaemonetes pugio) were exposed to the mosquito adulticide, Per manone(R) 31-66, in a series of static toxicity tests conducted in the laboratory. At 24 h, in order of decreasing susceptibility, LC(50) va lues were 0.843, 4.07, 5.46, and 6.04 ppb for grass shrimp, inland sil verside, sheepshead minnow, and mosquitofish, respectively. Forty-eigh t-hour LC(50) values for grass shrimp, inland silverside, sheepshead m innow, and mosquitofish were 0.049, 2.86, 3.02, and 4.29 ppb, respecti vely.