DAO 26:229-235 (1996)  -  doi:10.3354/dao026229

Nontarget testing of microbial pest control agents using larvae of the coot clam Mulinia lateralis

Gormly NM, Singer S, Genthner FJ

A short-term (48 h) chemical toxicity test using larvae of the coot clam Mulinialateralis was modified to evaluate potential toxicity and pathogenicity of microbial pest control agents. M. lateralis larvae, at the straight-hinged stage of development, were exposed to various microbial pest control agents including: a mosquito larvacide, Bacillus thuringiensis var. israelensis (Bti); a molluscicidal strain of Bacillusalvei; a viral pathogen of the gypsy moth Lymantriadispar nuclear polyhedrosis virus (LdNPV); and a broad host-range fungal insect pathogen, Metarhiziumanisopliae. Mortalities significantly higher than heat-killed controls were obtained with Bti at a 10-4 dilution of a commercial preparation, and with LdNPV at an occlusion body density of 1 x 106 ml-1. Sodium dodecyl sulfate (SDS) and the water-soluble fraction of No. 2 fuel oil (WSFoil) were also tested to provide a measure of comparison, sensitivity and precision. SDS, toxic at an LC50 of 6.3 mg l-1, had a mean coefficient of variation of 23%. The clam larval toxicity test was very sensitive to WSFoil; exposures resulted in an LC50 of <10% v/v. Because of its precision, sensitivity and simplicity, the M. lateralis larval test has the potential to be useful for assessing adverse effects that microbial pest control agents may have on nontarget bivalves.


Biological control · Nontarget effects · Mulinia lateralis


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