Contribution of Bacterial Gut Symbionts to Digestion and Development in Podisus maculiventris (Hemiptera: Pentatomidae)

Abstract

The spined soldier bug is a generalist predatory bug on many pest larvae across the world. The alimentary canal of this predator harbors facultative bacterial symbionts with unknown roles in the digestion and the development of their host. The present study deals with symbiotic roles in the production of digestive enzymes and development of Podisus maculiventris. Activities of general proteases and α-amylases of the midgut were assayed using the substrates hemoglobin and starch, respectively, in the antibiotic-treated and control insects. None of the aforementioned digestive enzymes were significantly suppressed in the absence of symbionts. Fecundity and adult longevity were influenced in antibiotic-treated adults. The total number of eggs/female and adult longevity in antibiotic-treated adults was lower and longer, respectively, than those of adults reared on the artificial or natural diet. However, suppression of bacteria resulted in no changes in pre-oviposition and oviposition periods, egg hatching, and adult weight. It seems that gut bacteria do not play a crucial role in digestive enzymes production. Nevertheless, they may be involved in the survival of the spined soldier bug.