Characterization of the symbiontRickettsiain the mirid bugNesidiocoris tenuis(Reuter) (Heteroptera: Miridae)

Abstract

AbstractNesidiocoris tenuis(Reuter) (Heteroptera: Miridae) is an omnivorous insect used for biological control. Augmentative release and conservation ofN. tenuishave been used for pest control in tomato crops. Intracellular bacterial symbionts of arthropods are common in nature and have diverse effects on their hosts; in some cases they can dramatically affect biological control. Fingerprinting methods showed that the symbiotic complex associated withN. tenuisincludesWolbachiaandRickettsia. RickettsiaofN. tenuiswas further characterized by sequencing the16S rRNAandgltAbacterial genes, measuring its amount in different developmental stages of the insect by real-time polymerase chain reaction, and localizing the bacteria in the insect's body by fluorescencein situhybridization. TheRickettsiainN. tenuisexhibited 99 and 96% similarity of both sequenced genes toRickettsia belliiandRickettsiareported fromBemisia tabaci, respectively. The highest amount ofRickettsiawas measured in the 5th instar and adult, and the symbionts could be detected in the host gut and ovaries. Although the role played byRickettsiain the biology ofN. tenuisis currently unknown, their high amount in the adults and localization in the gut suggest that they may have a nutritional role in this insect.