A short-term (48 h ) chemical toxlcity test using larvae of the coot clam A4ulinia lateralis was modified to evaluate potential toxlcity and pathogenicity of microblal pest control agents. M. lateralls larvae, at the straight-hinged stage of developn~ent, were exposed to varlous microbial pest control agents including a mosquito larvac~de. Bacillus thur~ngiensis var israelensis (Bti); a mol1usc1-cidal strain of Bacillus alvei; a viral pathogen of the gypsy moth Lymantria dispar nuclear polyhedrosis virus (LdNPV); and a broad host-range fungal insect pathogen, Metarhizium anisopliae. Mortalities significantly h~g h e r than heat-killed controls were obtained w~t h Bti at a 10-4 dilution of a colnlnei-cial preparatlon, and w~t h LdNPV at an occlus~on body d e n s~t y of 1 X 10%1-' Sodlum dodecyl sulfate (SDS) and the ivater-soluble fraction of No. 2 fuel 011 ( W S r ) were also tested to provide a measure of comparison, sensitlv~ty and precision. SDS, toxic at an LC,, of 6.3 m g 1-', had a mean coefficient of variation of 23'X). The clam larval tox~city test was very sensitive to WSF,,,,, exposures resulted In an LC.,,, of <10% V/\! Because of its preclslon, sensitivity and simplicity, the M. lateralis larval test has the potential to be useful for assessing adverse effects that microblal pest control agents may have on nontarget bivalves KEY WORDS: B~o l o g~c a l control Nontarget effects . Mullnja lateralis

No abstract