The purpose of this study was to examine the damage rate of insect pests on chestnut orchards. and to investigate the effects of varying methods of insect pests control. The results revealed that there was a statistically significant(p<0.05) difference among early-ripenign, middleripening, and late-ripening cultivars. The damage rate of Dichocrocis punctiferalis was highest in early-ripening cultivars(24.22%), followed by middle-ripening(22.71%) and late-ripening(20.25%). The damage rate of Curculio sikkimensis was highest in late-ripening cultivars(24.52%), followed by middle-ripening(22.61%) and early-ripening(19.96%). There was a statistically significant(p<0.05) difference in damage rates after insect pests control. Two methods of insect pests control, using either helicopter or an unmanned drone, were used. The results revealed significant differences (p<0.05) between D. punctiferalis and C. sikkimensis. Changes in the damage rates of D. punctiferalis after drone control were 8.97%~9.62%, and that after helicopter control was 14.82~15.94%, which was 20.25%~24.22% significant difference(p<0.05) from control site. Changes in damage rates of C. sikkimensis after drone spraying was 6.77~7.72%, and that after helicopter spraying was 12.62~14.94%, which was 19.96~24.52% significant difference(p<0.05) from control sites. Control effects of D. punctiferalis by drone spraying was 59.06% and helicopter spraying was 30.82%. Control effects of C. sikkimensis by drone spraying was 66.97% and helicopter spraying was 40.78%.

ABSTRACT
 Introduction
 Materials and methods
  1 Selection of study sites and period
  2 Damage rate per insect pests control method
  3 Statistics
 Results and Discussion
  1 Damage rate of chestnut fruits
  2 Change in damage rates after treatment
  3 Control value of chestnut insect pests by treatment method
 References

• Chong-kyu Lee(Dept. of For. Res., Gyeongsang National Univ. of Sci. and Tech.) Corresponding author