The distinctive dark glands covering most of the aelial parts of the cotton plant are well known to growers.

A great proportion of the Helicoverpa eggs laid onto cotton never hatch. They are either eaten by predators, dislodged from the plant by wind and rain, killed by climatic extremes, or are infertile.

The HEAPS (HE.licoverpa d.rmigera and l!.imctigera Simulation) model embodies all of our current knowledge on the ecology of Helicoverpa within cotton cropping regions.

Heliothis spp.