Protective effects of natural products and gut bacteria to reduce pesticide-induced mortality in honeybees

The population and diversity of honeybees face significant threats from agricultural pesticides. This study evaluated the protective effects of natural products, bee propolis, flaxseed oil, black seed oil, and gut bacteria isolated from the alimentary tracts of local honeybee (
Apis mellifera
jemenitica) of Saudi Arabia against four insecticides: acetamiprid, deltamethrin, imidacloprid, and alpha-cypermethrin. Thirteen gut bacterial strains, including
Bacillus australimaris, Peribacillus frigoritolerans,
and
B. siamensis
were isolated and assessed for their potential to enhance honeybee survival. Diets containing propolis or gut bacteria significantly extended the lifespan of bees exposed to pesticides. Propolis-fed bees survived 17.36, 20.14, 20.47, and 19.63 days under deltamethrin, acetamiprid, imidacloprid, and alpha-cypermethrin, respectively, compared to 15.63 to 18.29 days for gut bacteria-fed bees. Diets with flaxseed or black seed oil offered moderate protection (10.84- 14.38 days). The untreated control group had the highest survival (21.54 days), while pesticide-only groups showed the lowest survival (5.39-9.11 days). Daily consumption varied significantly across treatments. Propolis had the highest mean consumption (12.64 μL/bee/day), similar to the untreated control (14.51 μL/bee/day). Flaxseed and black seed oil showed moderate consumption rates (8.15-8.57 μL/bee/day), while gut bacteria diets reached 10.45 μL/bee/day. Pesticides reduced consumption significantly, with acetamiprid, deltamethrin, and imidacloprid yielding 3.16–4.34 μL/bee/day, and alpha-cypermethrin slightly higher at 6.10 μL/bee/day. These findings underscore the potential of natural products and gut bacteria in mitigating pesticide toxicity in honeybees, improving survival, feeding behavior, and overall health. The diversity of isolated gut bacteria highlights promising applications in apiculture and pollination services.