Safety evaluation of the entomopathogenic bacterium Brevibacillus laterosporus for the green lacewing Chrysoperla agilis (Neuroptera: Chrysopidae).

The safety of the entomopathogenic bacterium Brevibacillus laterosporus for the natural insect predator Chrysoperla agilis was evaluated in this study. For this purpose, laboratory bioassays were conducted exposing different larval instars and adults of the chrysopid to bacterial spore preparations, in order to evaluate the possible effects on survival, longevity, immature development, and adult reproductive performance. The sub-lethal effects were investigated by feeding the bacterium directly to adults and larvae of C. agilis or to mealworm beetles (Tenebrio molitor) used as hosts for chrysopids (tritrophic interaction). Direct feeding of B. laterosporus spores to different lacewing larvae instars and to adults did not cause mean mortality levels significantly different from untreated control, and slight though not significant effects of treatments were generally observed on insect longevity, development, fecundity and egg hatching. In the case of lacewing larvae feeding on treated mealworm beetles, adult emergence percentage was reduced approximately 12%, in comparison with untreated control. Based on these results, the use of B. laterosporus for pest management in the agroecosystem, appears to be compatible with chrysopids.

Inhibition of Paenibacillus larvae by an extracellular protein fraction from a honeybee-borne Brevibacillus laterosporus strain.

The inhibitory action that a Brevibacillus laterosporus strain isolated from the honeybee body causes against the American Foulbrood (AFB) etiological agent Paenibacillus larvae was studied by in-vitro experiments. A protein fraction isolated from B. laterosporus culture supernatant was involved in the observed inhibition of P. larvae vegetative growth and spore germination. As a result of LC-MS/MS proteomic analyses, the bacteriocin laterosporulin was found to be the major component of this fraction, followed by other antimicrobial proteins and substances including lectins, chaperonins, various enzymes and a number of putative uncharacterized proteins. The results obtained in this study highlight the potential of B. laterosporus as a biological control agent for preserving and improving honeybee health.