The importance of Heliothis has grown with the advent of resistance in H.armigera to various pesticides.

Heliothis spp.

To understand, and predict, Heliothis dynamics on cotton, along with changes in resistance levels, we must understand their dynamics on other hosts and the patterns of movement from these to cotton.

Host Plant resistance is one such method and has been adopted in developing plant resistance to a range of plant problems. Plants posses both natural physiological and chemical defence mechanisms.

Heliothis spp. have two main attributes which give rise to their pest status and make them difficult to manage (see Fitt this volume).