Heating condition effects on thermal resistance of fifth-instar Amyelois transitella (Walker) (Lepidoptera: Pyralidae)
Authors:
Wang, S. Johnson, J.A. Tang, J. Yin, X. USDA, ARS
Source:
Journal of stored products research. 2005, v. 41, no. 4, p. 469-478.
NALT Subjects:
heating systems Amyelois transitella instars heat stress heat tolerance mortality temperature pretreatment strain differences
Other Subjects:
thermal mortality heating block system conditioning heating rates heating death kinetics
Issue Date:
2005
Abstract:
Successful development of a thermal treatment protocol depends on reliable information on fundamental thermal death kinetics of targeted insects under different heating conditions. The effects of heating rates (1, 10, and 15 degrees C min(-1)), pre-treatment conditioning (30 degrees C + 6 h), and the difference between long-term laboratory cultures and recently isolated cultures on thermal mortality of fifth-instar navel orangeworm, Amyelois transitella (Walker), were studied using a heating block system. There was no significant difference in insect mortality resulting from heating rates of 10 and 15 degrees C min(-1). Temperature control at 1 degrees C min(-1) was more uniform than for the other heating rates, resulting in reduced variability for insect mortality. The mean mortality at the heating rate of 1 degrees C min(-1) was significantly lower than for the two faster heating rates only at 48 degrees C + 30 min. The pre-treatment conditioning of fifth-instar Amyelois transitella enhanced their thermotolerance only at certain temperature-time combinations. Fifth-instars from long-term laboratory and recently isolated cultures were equally susceptible to elevated temperatures. Therefore, thermal death kinetic information obtained from the long-term laboratory cultures can be used to develop thermal protocols against field pests.
