Mosquitocidal bacterial toxins: Diversity, mode of action and resistance phenomena

Bacteria active against dipteran larvae (mosquitoes and black flies) includ e a wide variety of Bacillus thuringiensis and B. sphaericus strains, as we ll as isolates of Brevibacillus laterosporus and Clostridium bifermentans. All display different spectra and levels of activity correlated with the na ture of the toxins, mainly produced during the sporulation process. This pa per describes the structure and mode of action of the main mosquitocidal to xins, ir? relationship with their potential use in mosquito and/or black fl y larvae control. investigations with laboratory and field colonies of mosq uitoes that have become highly resistant to the B. sphaericus Bin toxin hav e shown that several mechanisms of resistance are involved, some affecting the toxin/receptor binding step, others unknown.