Bacillus sphaericus mosquito pathogens in the aquatic environment

Abstract

The fate of Bacillus sphaericus spores in the aquatic environment was investigated by suspending spores in dialysis bags in fresh and seawater. Spore viability was lost more rapidly in seawater. Neither B. sphaericus nor B. thuringiensis israelensis (B.t.i.) spores mixed with pond sediment appeared to attach to the sediment. However, rapid decrease in B.t.i. toxicity suggested attachment of parasporal bodies to sediment. B. sphaericus toxin settled more slowly and less completely. B. sphaericus spores fed to larvae of four aquatic invertebrates were mostly eliminated from the animal gut in less than one week. An exception was the cranefly (Tipula abdominalis) where spores persisted in the posterior gut for up to five weeks.

Evaluating the Elimination of Brazilian Entomopathogenic Bacillus by Non-target Aquatic Species: An Experimental Study

“…2). Yousten et al (1995) reported that after feeding larvae of four aquatic non-target insects with B. sphaericus spores, three species eliminated all spores in less than 1 week. In research with the crustacean Gammarus lacustris, Brazner and Anderson (1986) observed that on the 7th day postexposure to B. thuringiensis subsp.…”