DAMAGE SYMPTOMS AND CONTROL TIMING BY APOLYGUS SPINOLAE (MEYER-DÜR) (HEMIPTERA: MIRIDAE) ON SWEET PERSIMMON IN KOREA

The pale green plant bugs (Apolygus spinolae (Meyer-Dür)) cause abscission of flower buds before flower opening, and perforation of leaves in sweet persimmon in Korea. The leaf perforation symptoms are exhibited as brown spots on newly opened young leaves which then form larger holes after the leaves are fully expanded. Damage to flower buds is caused by feeding on the lower surface of the calyx which results in browning, and finally flower drop. This therefore leads to the reduction in yields. In some orchards, the damage rate to leaves was found over 30% in 2006. Even with these significant losses, many farmers do not known what causes the damage or how to control the insect. The time of maximum damage was found to be in mid-late April for leaf perforations, and late April-early May for flower buds. To determine the optimum time for control, we applied 10% thiamethoxam WP at 5-day intervals from 10 April to 10 May in 2007. As a result, the recommended time for control is mid-late April, or the time of 2-3 young leaves expansion.