Effects of tetracycline and rifampicin treatments on the fecundity of the Wolbachia-infected host, Tribolium confusum (Coleoptera: Tenebrionidae)

Citation

Li, Y.Y., Fields, P.G., Pang, B.P., Floate, K.D. (2016). Effects of tetracycline and rifampicin treatments on the fecundity of the Wolbachia-infected host, Tribolium confusum (Coleoptera: Tenebrionidae). Journal of Economic Entomology, [online] 109(3), 1458-1464. http://dx.doi.org/10.1093/jee/tow067

Plain language summary

Wolbachia are bacteria that infect an estimated 20-70% of all insect species. Wolbachia can promote their spread in the insect population by altering host biology and reproduction. This study shows that: 1) antibiotics can be used to remove infections of Wolbachia from the flour beetle Tribolium confusum, and 2) infections cause female flour beetles to lay sterile eggs if they mate with uninfected males. These findings add to the body of knowledge on how Wolbachia manipulate their insect hosts in order to aid future research for use of Wolbachia as a means to reduce populations of pest insects. These findings also provide insights into use of antibiotics in Wolbachia research.

Abstract

We examined the effects of Wolbachia bacteria on the reproduction of the flour beetle Tribolium confusum (Coleoptera: Tenebrionidae) using different antibiotics and across generations. We first removed infections by rearing insects on a diet with tetracycline (T; 1.0, 2.0, 3.0, 5.0, 10.0 mg/g) or rifampicin (R; 0.1, 0.2, 0.3, 0.5, 1.0 mg/g). We then performed experimental crosses using adults two generations (G2) and four generations (G4) removed from antibiotic treatments. Results showed that use of rifampicin more readily cured infections. Egg hatch from crosses of uninfected females and infected males was 0, but averaged 84 to 91% for eggs from all other crosses. Elevated fecundity was observed for T-G2 females, but not for T-G4, R-G2, or R-G4 females. Cross type had little or no effect on the sex of F1 offspring, which averaged 52% female. These collective results support previous findings that show that Wolbachia in T. confusum causes 100% cytoplasmic incompatibility and emphasize that the antibiotic treatment used to remove infections may have additional consequences (e.g., elevated fecundity) that may not be apparent in subsequent generations.