D3468: Relationship between genetic variability and microsporodia infection of the oriental beetle, Exomala orientalis, in South Korea

The oriental beetle, Exomala orientalis, is one of the major insect pests in the golf courses in Korea. Larvae are the major developmental stage causing the grass browning and withering. Microsporodia, Ovavesicula popilliae, was recently suggested as the natural enemy to control Japanese beetle, Popillia japonica, since beetles infected by O. popilliae showed high larval mortality and low reproduction. In Korea, O. popilliae-infected E. orientalis was recently reported from northern and southern area but not from central. In order to understand the relationship between genetic variability of E. orientalis and infection rate of O. popilliae, mitochondrial cytochrome oxidase subunit Ⅰ (COⅠ) was selected and compared among the populations collected from 13 golf courses in Korea: Gapyeong, Gwangju, Yeoju, Anyang, Yongin-L, Yongin-G, Icheon, Yecheon, Kimcheon, Seonsan, Waegwan, Busan, and Namhae. The oriental beetles were mainly divided by northern and southern, which was correlated with infection of microsporodia. We suggest that genetic background of E. orientalis affects the rate of infection of O. popilliae.