Prevalence of Wolbachia in 10 Tenebrionidae stored product insects and infection density dynamics in confused flour beetle Tribolium confusum (Jaquelin Du Val) (Coleoptera: Tenebriondae)

Background: Increasingly interests in the potential use of insect symbionts Wolbachia to control populations of pest species were focused on many vector pest species and agricultural insects. However, few pieces of researches were reported in stored product insects. Methods: We surveyed the prevalence of Wolbachia using a PCR detection method in 10 Tenebrionidae stored product insects. Subsequently, Wolbachia infection density and spatiotemporal dynamics in Tribolium confusum were investigated in detail by TaqMan probe real-time quantitative PCR, and Wolbachia elimination patterns by antibiotic treatment and host reproductive fitness parameters were compared. Results: Our results identified that T. confusum were the only infected species in the survey. Wolbachia infection density consistently increased with the development of T.confusum and plateaued at 3.7×10 7 wsp copies per individual insect at the young adult stage. Wolbachia densities in females showed significant differences to the male at the pupae stage and varied in different tissues and organs.Aposymbiotic female beetles by feeding with Tetracycline diet were completely incapable to produce mature progenies when crossing with Wolbachia infected males. Embryogenesis and egg hatch rate were specifically inhibited after Wolbachia elimination, while other traits including egg produced numbers, pupation rate and sex ratio remained unaffected after antibiotic treatment. Discussion: All the results indicated that Wolbachia infection was regarded as a mutualism but not obligate symbiont and benefited the host confused flour beetle.