The study investigated the chemical treatment effects on apple borers (Lepidoptera: Totricidae, Carposinidae) when the larvae already bored inside the apple fruits. Infested apple fruits were harvested from the insecticide-free orchards in Giran, Andong on 17 July, 2010. Twenty chemical pesticides registered for the apple borers were treated on recommendation dose with dipping methods. Each treatment consisted of 20 infested apples with average 6.2 larva per apple. Mortality was relatively low, mostly 10% and a few with 30~40%. No larva died inside the apple. But dying larva escaped from apple much earlier than live ones. However there was significant sublethal effect.. Escaping time (d) from chemical treatments was longer than that from control where no chemical was treated. After escaping from the apple, in took ap. 2days to become pupae. Pupal periods were ap. 12 days without any difference among treatments. However adult emergence rate was higher in control (10.7%) than in treatments (18.5%). Among survived adults, one third was Carposina sasakii and remaining was Grapholita molesta. On conclusion, timing of insecticide spray is critical in the apple borer management.

• Lalit Prasad Sah(Department of Bioresource Sciences, Andong National University)
• Seon A Jeong(Department of Bioresource Sciences, Andong National University)
• Chuleui Jung(Department of Bioresource Sciences, Andong National University)