Study on Dioryctria yiai

Dioryctria yiai Mutuura et Munroe is a serious forest pest that damages staminate branch, cone and shoot of Pinus massoniana in China. The studies on the biology and control of this insect pest were carried out in Chunan County, Zhejiang Province in 1987~1990. D. yiai completes one generation a year with overwintering as larva in damaged staminate branch, cone and shoot. The paper describes the ecological relationships among the occurrence of the insect and forest climate, host and natural enemy. Experimental results showed that blacklight trap, spraying with the insecticides of SN-851 and 8302 in early spring were effective.