Insecticidal Activity of Plant Oils, Bacterial Endotoxins and their Combinations against Musca domestica L.

AbstractThe toxic proteins of Bacillus thuringiensis israelinsis (Bti) and Bacillus sphaericus 2362 (Bs) were tested either singly or in combination with plant oils and chemical insecticides against the larvae and adults of Musca domestica in laboratory. Based on the 24h-LC50 values, the essential oil from Apium graveolens showed the highest toxicity against the house fly larvae (59.4 ppm), while Petroselium crispum oil was the highest toxic to the fly adults (0.62 ppm). The Bti toxin proved to be more toxic than the Bs one. The nine plant oils, at sublethal concentrations, induced severe developmental effects represented by suppression of adult emergence and causing different forms of deformations. Also, the plant oils showed considerable repellent effect against the house fly adults. Combining Bti or Bs endotoxins with plant oils or insecticides induced synergistic action against the larvae and adults of the tested insect. The analysis of the tested oils by GC-MS indicated the dominance of several terpe...