Technical Working Paper 02-105

Thermal Death Kinetics and Heating Rate Effects for Fifth-Instar Codling Moths (Cydia Pomonella (L.)), S. Wang, J.N. Ikediala, J. Tang, and J.D. Hansen February 2002

Abstract

Thermal death kinetic parameters of fifth-instar codling moths (Cydia pomonella (L.)) and the effect of these heating rates (1, 10 and 18°Cmin^-1 ) on larvae mortality were determined by a heating block system. The insects were heated to four temperatures (46, 48, 50 and 52°C) held for predetermined periods followed by 24 hr storage at 4°C before mortality evaluation. Thermal death kinetics for fifth-instar codling moths followed a 0.5^th order of kinetic reaction. Minimum time required to achieve 100 percent mortality of a given population decreased with temperature in a semi-logarithmic manner. No larva survived was observed in samples of 600 insects after holding at 46, 48, 50 and 52°C for 50, 15, 5 and 2 min, respectively. Activation energy for thermal kill of fifth-instar codling moths at the heating rate of 18°Cmin^-1 was estimated to be about 472 kJmol^-1. The lethal time cumulated during the ramp period was about 1.8, 0.2 and 0.1 min for the heating rates of 1, 10 and 18°Cmin^-1, respectively.