Structural heat treatment for disinfesting insect pests in food-processing facilities

Abstract

Purpose of the review: This review describes methods for successful application of heat treatment to manage stored-product insect pests in food-processing facilities and distinguishes between structural and commodity heat treatments. It also discusses stage-specific susceptibility of insects to elevated temperatures, effects of elevated temperatures on insect development, survival and reproduction, and mechanisms of heat tolerance. Further, the review identifies many research needs in this area. The information and useful citations presented in this review provide substantial knowledge about structural heat treatments. Findings and limitations: Methyl bromide, a fumigant traditionally used as a space fumigant for insect management, is an ozone depleter that has been phased out in the USA and elsewhere. The use of elevated temperatures, or heat treatment, is gaining popularity as a methyl bromide alternative. Heat treatment involves raising the ambient temperature of a facility to 50–60 o C and holding these temperatures for 24–36 h. The major challenge with heat treatment is non-uniform distribution of the heated air caused by temperatures stratifying both horizontally and vertically within the heated facility. Thus, some portions of the facility may be over-heated (>60 o C), resulting in inefficient use of the generated heat, whereas other portions may be under-heated (<50 o C), resulting in survival of the tar