Insecticide activity of surfactins and iturins from a biopesticide Bacillus subtilis Cohn (S499 strain).

Surfactin C14, surfactin C15, and iturin C15 are lipopeptides purified from Bacillus subtilis (S499 strain). They were incorporated to artificial diet of the fruit fly Drosophila melanogaster (Meigen) (Diptera, Drosophilidae) to assess their potential insecticide activity. Surfactins with long fatty acid chain (C14 and C15) showed insecticide effect on the fruit fly, D.

Increased fecundity of malathion-specific resistant beetles in absence of insecticide pressure.

Despite that resistance frequency is assumed to decline when selective pressure is relaxed, the stability of resistance frequency has been observed in some insects in the absence of insecticide. In the red flour beetle, Tribolium castaneum, the first case of malathion-resistance was reported in the early 1960s. The malathion-specific resistant phenotype has now almost completely replaced the susceptible one in red flour beetle populations.