Learning in Helicoverpa armigera (Lepidoptera : Noctuidae): a new look at the behaviour and control of a polyphagous pest

Recent experimental evidence has shown that learning occurs in the host sel ection behaviour of Helicoverpa armigera (Hubner), one of the world's most important agricultural pests. This paper discusses how the occurrence of le arning changes our understanding of the host selection behaviour of this po lyphagous moth. Host preferences determined from previous laboratory studie s may be vastly different from preferences exhibited by moths in the field, where the abundance of particular hosts may be more likely to determine ho st preference. In support of this prediction, a number of field studies hav e shown that the 'attractiveness' of different hosts for H. armigera ovipos ition may depend on the relative abundance of these host species. Insect le arning may play a fundamental role in the design and application of present and future integrated pest management strategies such as the use of host v olatiles, trap crops and resistant crop varieties for monitoring and contro lling this important pest species.