The cotton bollworm is affecting crops of canola in the Central West Slopes and Plains district of New South Wales. Helicoverpa armigera – also known as the corn earworm – have been munching their way through pods and stems just North of Gilgandra.
The pest ranges from Southern Queensland all the way down to Tasmania and attacks a wide range of crops including cotton, sorghum, maize, sunflowers, chickpeas, lupins and lucerne. In cooler climes, the pupae of the caterpillar hibernate in the soil during Winter in a state of suspended development (diapause). The moths then usually emerge in October.
Helicoverpa armigera are known to be fairly resistant to pesticides with predators and pathogens recommended as population control tools. Pupae busting is also possible. Pheramone traps can be used to monitor the numbers of the emerging moth population.
