Thermal death kinetics and heatingrate effects for fifth-instar Cydia pomonella (L.) (Lepidoptera: Tortricidae)

Authors

S. Wang, Washington State University
J. N. Ikediala, Washington State University
J. Tang, Washington State University
J. D. Hansen, USDA-ARS

Date of this Version

2002

Comments

Published in Journal of Stored Products Research 38 (2002) 441–453.

Abstract

Thermal death kinetic parameters of fifth-instar codlingmoths (Cydia pomonella (L.)) and the effect of three heating rates (1°Cmin^-1, 10°Cmin^-1, and 18°Cmin^-1) on larval mortality were determined by a heatingblock system. The insects were heated to four temperatures (46°C, 48°C, 50°C, and 52°C) held for predetermined periods followed by 24 h storage at 4°C before mortality evaluation. Thermal death kinetics for fifth-instar codlingmoths followed a 0.5th order of kinetic reaction. Minimum time required to achieve 100% mortality of a given population decreased with temperature in a semi-logarithmic manner. No larval survival was observed in samples of 600 insects after exposure to 46°C, 48°C, 50°C, 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 kJ mol^-1. The lethal time accumulated duringthe ramp period was about 1.8, 0.2, and 0.1 min for the heatingrates of 1°Cmin^-1, 10°Cmin^-1, and 18°Cmin^-1, respectively.