Control effects of the oak borer platypus quercivorus (coleoptera: Platypodidae) by spraying trunk surface with fenitrothion

Abstract

sprayed the trunk surface lower than 6 m above ground level with 1.6% fenitrothion once before the occurrence of Platypus quercivorus adults in Quercus serrata and Q. crispula forests. The number of captured males and this attack density were five times higher in the Q. serrata forest than in the Q. crispula forest. In the Q. serrata forest, the control rate of initial attacks was 100% for 1∼3 weeks and it decreased to 50% five weeks after spraying. The incidence of capturing more than six males, which indicated the control effect on the initial attacks emerged 22 times and concentrated on 1∼5 weeks after spraying. The mass-attack controlling effect was also observed during this period. In the Q. crispula forest, the rate of control of the initial attack was 100% for 5∼7 weeks and it decreased to about 80% there after. The boring density on the trunk surface lower than 6 m height, where fenitrothion had been sprayed, was less than in non-sprayed trees, and the difference was the largest in the 0.5∼1.5 m height range in the Q. serrata forest. These results suggest that spraying fenitrothion should be effective to control boring by P. quercivorus adults and that spraying of 1.6% fenitrothion once can have a high control effect on boring over a period of more than three weeks.