Life history and spatial distribution of Oriental beetle (Coleoptera: Scarabaeidae) in golf courses in Korea.

Larval and adult activity of the oriental beetle Exomala orientalis (Waterhouse), a pest of turfgrass in Korea, was investigated at four golf clubs in Pusan, Korea, from 1995 to 1999. Adult emergence was first observed on the greens in late May with peak activity occurring 2 wk later. During the day, E. orientalis adults were most active between 1800 and 2200 hours. First instars were found mostly in early July, second instars mostly in late July, and third instars from August to April. The density of larvae in fixed plots decreased steadily from the time of egg laying to pupation: 667/m3 on 26 July, 267/m3 on 29 August, and 122/m3 on 2 October 1997. All the observed E. orientalis completed one generation per year. Adult females were observed feeding on flowers of a late-blooming variety of Japanese chestnut (Castanea crenata Sieb & Zucc). E. orientalis larval densities were higher in greens with Japanese chestnut nearby, and where magpie, Pica pica sericea (Gould), feeding was observed. More E. orientalis adults emerged from the right, left, and back of greens than from the front or middle. The intensity of emergence was inversely proportional to the amount of golfer traffic on various parts of the green. Counting emergence holes may be a way that golf course superintendents can predict which greens and tees are most likely to be damaged from E. orientalis larvae without destructive sampling.