This project validated and enhanced the use of the BDI as a measure of the relative disruption

(‘softness’/’hardness’) of the insecticide regimes applied to cotton fields. The project focused on two

Area-Wide Management groups in Northern NSW: The Boggabilla landcare group in the Macintyre

valley, and the near Pilliga, NSW. Intensive

sampling of pest and beneficial insects was undertaken on fields within both groups, and the paddock

level data was analysed in association with agronomic, spray and yield data provided by growers and

consultants.

The project quantified how the insecticide programs applied to individual cotton fields affected

populations of beneficial insects and spiders present in those fields. The project also compared the

abundance and diversity of insects and spiders in Bt and conventional cotton fields. A comparison of

the effectiveness of different sampling methods for measuring the was also undertaken.

By exploring the relationships between pests, beneficials, spray regimes and economic performance of

individual fields within AWM groups, this project has collected a unique large scale and multi-season

data set. The results have been analysed within the context of area-wide management. The results

strongly suggest that IPM applied on an areawide scale is at least as profitable as more disruptive

approaches, whilst minimising environmental impacts and potentially reducing the risk of resistance to

insecticides increasing.

By quantifying the linkages between beneficial arthropods, Helicoverpa densities, spray regimes and

the economic performance of individual fields this project provides information that will assist AWM

groups to better manage their insect pests (particularly Helicoverpa) in a sustainable and profitable

manner.

Project CSE103C has been interwoven with the Macintyre Valley IPM / IRMS Trial. In particular, M.

Dillon was a member of the Trouble Shooting Committee for this trial, provided assistance with the

analyses of insecticide use and bug checking data arising from the trial, and helped present findings to

the TIMS Committee. The trial data were supplemented with invertebrate data collected

independently in this project, and earlier studies (especially through interactions with the Boggabilla

Landcare group when developing the BDI concept).