Effects of heating rate on the mortality of lightbrown apple moth

Abstract

The effect of heating rate on mortality of fifth instar Epiphyas postvittana (Walker) was investigated. Insects were treated in air or water ramped to target temperatures over a range of times. Hot air treatments where the temperature of the air was increased from 20 to 43°C in 1, 2 and 4 h were associated with lethal times for 99% mortality (LT99) that were 29.8, 45.8 and 44.6 minutes longer than the LT99 for LBAM exposed to air at 43 oC throughout the treatment. In contrast, no increase in tolerance was observed if the insects were immersed in water which was heated to a target of 43oC over similar ramp durations. Keywords: lightbrown apple moth, Epiphyas postvittana, thermo- tolerance, heating rate.