The cost of symbiont disruption: Antibiotic-induced shifts in secondary symbionts reduce population fitness in the greenhouse whitefly

Abstract

Insects maintain diverse symbiotic relationships with microorganisms that influence their physiology, development, and adaptability. This study investigates the impact of antibiotic treatments on the life history parameters and symbiont composition of Trialeurodes vaporariorum (isolate Zibashahr), a significant agricultural pest. A whitefly population was treated with tetracycline (Tet.), rifampicin (Rif.), or a cocktail of ampicillin, cefotaxime, and gentamicin (A.C.G.) and then, symbiont abundance was assessed through quantitative PCR, while life history parameters were analyzed using age-stage, two-sex life table methods. The qPCR analysis indicated no significant change in the abundance of Portiera. However, populations of Arsenophonus were markedly reduced following exposure to both Rif. and the A.C.G., whereas Hamiltonella and Rickettsia displayed significant increases. These shifts in microbial composition corresponded with noticeable changes in whitefly development, adult longevity, survival rates, and life expectancy compared to controls. These findings suggest that antibiotic-induced shifts in symbiont populations can impact the fitness of T. vaporariorum, providing important insights for integrated pest management approaches.