The effects of antibiotic treatments on the endosymbionts and fitness of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Encarsia lutea (Masi) (Hymenoptera: Aphelinidae)

This study aimed to determine the temporal changes in the endosymbionts of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) (B and Q biotypes) and Encarsia lutea (Masi) (Hymenoptera: Aphelinidae) caused by two different antibiotic diets, Rifampicin and Tetracycline, and assess the effects of endosymbiont infection rates on the biological parameters of B. tabaci and E. lutea by comparing populations treated with antibiotics to control populations. Rifampicin and Tetracycline treatments have negatively affected the biological parameters of two B. tabaci (B and Q) biotypes. In the Rifampicin treatment, the immature development time and mortality rates of the F1 generation of B. tabaci B biotype increased while the number of laid eggs decreased. Additionally, life table parameters such as net reproductive rate (R0) and intrinsic rate of increase (rm) were found to be much lower compared to the control and Tetracycline treatments. Molecular studies have revealed that although antibiotic treatments did not completely eliminate endosymbionts in B. tabaci immature stages and adults, they significantly reduced the infection rates. The effect of the antibiotics depended on the species of endosymbiont, and the B. tabaci biotype, with Rifampicin being more successful in eliminating Portiera in the B biotype compared to the Q biotype. Tetracycline treatment was more effective on Rickettsia compared to Rifampicin. This study determined that antibiotic treatments could not completely eliminate Wolbachia in adult female and male individuals of E. lutea but significantly reduced its prevalence. Following tetracycline treatment, no parasitized individuals were obtained when Wolbachia-infected males were mated with uninfected females due to cytoplasmic incompatibility. In the Rifampicin treatment group, the number of parasitized individuals was very low (1.41 individuals). It is believed that antibiotic treatments induce a decrease in endosymbiont infection rates, and consequently influencing the biological parameters of both B. tabaci and its parasitoid, E. lutea.