Insecticidal potential of Brevibacillus laterosporus against dipteran pest species in a wide ecological range.

In order to increase our understanding of the insecticidal potential of the entomopathogenic bacterium Brevibacillus laterosporus strain UNISS 18 against insect pests, investigations were conducted on a selection of dipteran species including fruit flies, house flies, blow flies, and mosquitoes, characterized by adaptations to very diverse habitats. According to lethal concentration (LC) values, the common house mosquito Culex pipiens (LC = 0.10 × 10 spores/mL) and the yellow fever mosquito Aedes aegypti (LC = 0.18 × 10 spores/mL) were significantly more susceptible than the flies. The blow flies were the second taxon in term of susceptibility to B. laterosporus spores, with a higher mortality in Calliphora vomitoria (LC = 78.84 × 10 spores/mL) than Lucilia caesar (LC = 148.30 × 10 spores/mL). The effectiveness of B. laterosporus spores was reduced by half in the house fly Musca domestica (LC = 82.41 × 10 spores/mL). The lowest susceptibility was observed in the fruit flies, among which the spotted wing drosophila (SWD), Drosophila suzukii, was the most susceptible (LC = 217.51 × 10 spores/mL) in comparison with the medfly Ceratitis capitata and the olive fly Bactrocera oleae (LC = 2567.32 and 2567.36 × 10 spores/mL, respectively). The present study demonstrated that significantly different degrees of susceptibility are associated with diverse dipteran species including plant and animal parasites, and we suggest that B. laterosporus established different relationships with dipteran species in different ecosystems.