ABSTRACT
This chapter describes the initial results of research that may lead to a novel strategy for the control of insect pests that naturally overwinter in exposed sites or whose environment can be artificially cooled. A pure liquid or solution that remains unfrozen at temperatures below its equilibrium freezing point is said to be supercooled. In insects the temperature at which ice nucleation occurs is termed the supercooling point. Many insects can physiologically regulate their supercooling capacity. In the 1970's, ice nucleating active bacteria was discovered in association with plants and decaying leaves. Even if a bacterial strain carries the gene for ice nucleating activity, its phenotypic expression generally varies considerably from cell to cell, even in the same culture. To use ice nucleating active microbes under field conditions it is necessary to have a thorough understanding of the natural mechanisms of cold-hardiness of the insect within its natural hibernaculum.
