Exogenous Bacteria Play a Role in the Ability of Blow Fly Larvae to Develop on Resources with Variable Nutrient Quality

Effects of exogenous bacterial on host (Lucilia sericata, Diptera: Calliphoridae) associated microbial community under varying nutritional constraints were investigated. Proteus mirabilis, a presumably beneficial bacterium, and Salmonella, a pathogenic bacterium, were introduced to L. sericata larval diets with varying protein and lipid ratios. The introduced bacteria in combination with diet makeup altered bacterial communities associated with larval and pupal stage of L. sericata, as well as with life-history traits including larval duration (accelerated development 0.6 day, 10%) with increasing concentration of the introduced bacteria), pupal weight (increased 10%), and pupation proportion (increased 9.9%, when reared on the higher protein diet). Microbial communities shifted when reared with blow fly larvae and introduced microbes as well. The imbalanced microbial community induced by the exogenous bacteria converged once the immature fly reached the adult stage with the exogenous bacteria no longer being the dominant taxon. However, the long-term benefits of bacteria-diet interactions during immature development and longevity of resulting adults reared on low protein increased by 15% when exposed to the beneficial bacteria. These data demonstrate exogenous bacterial have variable ecological roles in the development of fly larvae and impact resulting adults.