Predatory Arthropods in Australian Cotton Fields
Feb 14, 2019
Over 50 species of predatory arthropods have been recorded in Australian cotton fields. The complex of generalist predators in Australian cotton has similarities and differences to those in other countries. It is dominated by coccinelids and other beetle species, bugs, ants and spiders. These predators attack Helicoverpa armigera and H. punctigera, the key pests of Australian cotton but also affect other pests such as mites and aphids and prey species with little economic impact suck as leafhoppers. Helicoverpa spp. are primary pests in Australian cotton. Under most pest management regimes predators do not maintain Helicoverpa numbers below current economic thresholds and predator population densities do not appear to be related to Helicoverpa abundance. In contrast, mites and aphids are usually secondary pests whose abundance is determines in part by the impact of pesticides on their natural enemies. This paper will review the predatory species involved, their abundance and seasonal phenology in cotton other crops and non-crop vegetation and the relatively limited data on their impact on Helicoverpa spp. The prospects for enhancing the role of predators of IPM will be discussed in relation to current trends in Australian cotton pest management.