Controlled atmosphere and temperature treatment system to disinfest fruit moth, Carposina sasakii (Lepidoptera: Carposinidae) on apples.

Carposina sasakii Matsumura (Lepidoptera: Carposinidae) is a serious pest of apples and peaches in Korea and Japan. Because of its limited distribution, C. sasakii has been identified as a quarantine pest in several countries. The Controlled Atmosphere/Temperature Treatment System (CATTS) was tested as an alternative to methyl bromide fumigation to control C. sasakii in apples. The fifth instar was the most tolerant immature stage to a heat treatment of 44 degrees C for 20 min. When the apples infested with different stages of C. sasakii were treated under CATTS conditions (heating rate of 16 degrees C/h, chamber temperature of 46 degrees C, final core temperature of 44 degrees C under 1% O2/15% CO2 atmosphere), young larvae (first-fourth instars) did not survive after 40 min exposure, but the fifth instars required an exposure of at least 60 min to attain 100% mortality. A partial heat shock protein 90 (hsp90) was cloned and showed inducible expression in response to heat shock at 44 degrees C. CATTS suppressed transcription of the hsp90 gene. Apples did not show any appreciable loss of quality in relation to fruit firmness, sweetness, and decay after a 60 min CATTS treatment. These results suggest that CATTS can be applicable to control C. sasakii in apples.