Bacillus sphaericus mosquito pathogens in the aquatic environment

• Main Authors: Allan A Yousten, Ernest F Benfield, Fred J Genthner
• Format: Article
• Language: English
• Published: Instituto Oswaldo Cruz, Ministério da Saúde 1995-02-01
• Series: Memórias do Instituto Oswaldo Cruz.
• Subjects: Bacillus sphaericus; Bacillus thuringiensis israelensis; mosquito pathogenic bacteria; bacterial spores; Chironomus riparius; Paragnetina media; Pteronarcys proteus; Tipula abdominalis; biological control
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02761995000100024
• ISSN: 0074-0276; 1678-8060

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.