The primary purpose of DAQ 122C was to investigate alternative pest management options under central Queensland conditions with a view to supporting and expanding the role of area wide management. The project accomplished of a broad suite of research spanning the use of assassin bugs as applied biological control agents through to investigating the potential of using attract and kill technology (Magnet®) for the management of Helicoverpa and Bt resistance.

The threat of ascochyta leaf blight disease gaining a foot-hold within the CQ chickpea industry provided an impetus to re-investigate alternative legume options for spring trap cropping. Field peas (cvs Alma or Glenroy) were found to be the most effective legume for Helicoverpa trap cropping and were unique in that the majority of eggs laid on it perished due to dislodgement from the waxy foliage making it a partially self-maintaining trap crop. The adoption of field peas for spring trap cropping circumvents any problems associated with chickpea leaf blight disease.

The use of refuges to augment natural enemies in cotton was investigated, with niger identified as being attractive to the broadest range of natural enemies. However, the use of refuges was found to be a inconsistent method for augmenting natural enemies commonly associated with cotton systems. The patterns of natural enemy abundance observed in the refuge treatments were probably more closely associated with variations within the surrounding environment than any in-field modifications to vegetative biodiversity via the provision of refuges. These results suggest that the key to reliably predicting and augmenting endemic populations of natural enemies within cotton farming systems may potentially exist in developing a more refined understanding of the interactions that occur between beneficial species and the broader natural environment.

The assassin bug, Pristhesancus plagipennis was demonstrated to be an effective biological control agent for Helicoverpa and mirids in conventional cotton. Assassin bugs were found to be innately tolerant of Steward®, Admiral®, Tracer®, Regent® and Affirm®, as well as NPV and Bt biopesticides. The compatibility of these products with assassin bugs in the field is highly desirable and our experiments demonstrated that the strategic integration of these insecticides with releases of assassin bugs provided effective pest management with 50% less insecticide whilst maximising crop yield. Should assassin bugs become commercially available in the future, significant potential exists utilise them within a low spray IPM program for conventional cotton.

Population dynamic studies demonstrated that Silver Leaf Whitefly, Bemisia tabaci Biotype (B) has become a regular pest of cotton within the Dawson Valley, infesting crops each year during late November and December and peaking in abundance during February. Sampling has also determined that native Eretmocerous parasitoids have become well established with their increased abundance correlating with a reduction in regional whitefly populations on cotton. Mean parasitism rates recorded in cotton have risen from 15% in 2003 to 87% in 2005 whilst applications of Insect Growth Regulators (IGRs) for whitefly control have decreased from 40% to <5% of fields over the same period. The reduction in IGR use constitutes savings of $100 per hectare not treated. Our data suggest that it is imperative to ensure the compatibility of pest management practices with whitefly parasitoid conservation and that this consideration will continue to influence future pest management research.

DAQ122C identified the potential for using Magnet® as a regional moth busting tool for targeting last generation Helicoverpa emerging from Bollgard® fields. Such an approach could supersede the requirement for summer trap cropping as part of the CQ Bt resistance management strategy and will be the focus for future research. Refinement of the current Bt resistance management strategy is of critical importance to ensuring the prolonged viability of pesticide reducing transgenic technologies.

Best pest management practices and novel research outcomes were promoted to CQ cotton growers throughout DAQ122C via several interactive field days each season and the provision of significant technical support and input for three IPM short courses conducted in the Dawson Valley and Central Highlands regions of CQ.