Molecular characterization of Rickettsia sp in a bruchid beetle, Kytorhinus sharpianus (Coleoptera: Bruchidae)

An endosymbiotic/parasitic bacterial associate was detected by diagnostic PCR experiments in the bruchid beetle, Kytorhinus sharpianus. Molecular phylogenetic analysis of the 16S rDNA sequence demonstrated that the bacterium is a new member of the genus Rickettsia. Among four bruchid species of three subfamilies examined,the Rickettsia was detected only in K. sharpianus. Not all individuals of K. sharpianus possessed the Rickettsia, suggesting that the microbe is likely to be a facultative companion of the host insect, rather than an obligate symbiont.