Diversity and Wolbachia infection in rice insect pests from Thailand
Panukorn Boonsit, Itsanun Wiwatanaratanabutr
Wolbachia is the genus of an endosymbiont that is infected in many arthropod species. Wolbachia plays a role in the reproductive system as a reproductive manipulator of its hosts. In Thailand, Wolbachia has been detected in many insects but a little is known about insect pests from rice fields. This research project is the investigation of these endosymbionts in insects from rice fields. Rice fields in Phetchaburi and Nakhon Ratchasima provinces in Thailand have not yet been reported to use a high level of insecticides; as a result, these areas still have a high diversity of insects. Samples were collected from October 2018 to September 2019. From this study, there were 418 individuals of insect pests in 7 orders (Hymenoptera, Lepidoptera, Coleoptera, Orthoptera, Diptera, Isoptera and Homoptera), 12 families in total of 17 species including snout weevil, ants, white grub, pyralid stem borer, termites, rice root aphid, mealybug, rice seedling fly, flea beetles, leaf beetle, wireworms, citrus locust, Bombay locust, Oriental migratory locust, Cyrtacanthacris locust, Brown planthoppers and White backed planthoppers which collected from rice fields. These rice insect pests have been collected from three different regions of Thailand. In addition, the number of rice insect pests collected by hand sampling, swing and pitfall trap has the significant positive correlation with the relative moisture in the air. The detection of Wolbachia infection in rice insect pests was determined by polymerase chain reaction using wsp primers to confirm the infection status of Wolbachia and their genetic diversity. Wolbachia was detected in mealybug, brown planthoppers and white backed planthoppers from collected specimens in Thailand. These findings indicated that Wolbachia are distributed throughout the rice field insect populations from Thailand.