PROJECT OBJECTIVES To monitor pyrethroid, endosulfan, organophosphate and carbamate resistance in H. armigera and H. punctigera. from all cotton areas and to refine resistance management strategies. Determine the genetic basis of carbamate in H. armigera and H. punctigera and organopbosphate resistance in H. armigera To develop and promote use of rapid biochemical techniques for the detection of organophosphate and carbamate resistance in the field. To evaluate new insecticides for Helicoverpa control, establish baseline susceptibility data and investigate their inherent resistance potential

The project aims are: * Construction of additional cages to isolate field-collected strains of A. gossypii. * Establishment of additional base-line data. * Generation of monitoring data against endosulfan bifenthrin, esfenvalerate, deltamethrin pirimicarb, dimethoate and profenofos for field-collected strains of A. gossypii using a discriminating-dose technique * To conduct full log-dose assays on strains that do not show 100% mortality at the discriminating-dose to give resistance levels.

The aim of this study was to (1) improve our understanding of predator responses to prey, predator/prey interactions and factors limiting their efficacy in cotton systems, (2) improve the performance of Envirofeast product developed in DAN 68 and 89C (3) develop strategies to attract, conserve and utilise beneficial insects as basic components of IPM in cotton and (4) manage green mirids and aphids through conservation of beneficial insects.

The silverleaf whitefly (SL W), Bemisia tabaci B-biotype, was first discovered in Australia in 1994. SLW is a major pest of cotton in many overseas countries and poses a considerable threat to cotton in Australia. Consequently a monitoring system using surveys has been run over the past two years to: * Monitor the distribution and abundance of the whitefly, * Record its hosts, and * Assess the degree of natural biological control provided by indigenous parasitoid

We have developed a reliable and cost-effective plan for deciding whether a crop has sufficient green mirids to warrant controlling them. This method provides an industry-wide standard that all consultants can use to accurately estimate green mirid populations. Consultants and fanners now have two different strategies, insecticides alone or with luceme strips (as developed by Dr R. Mensah), to manage green mirids in cotton. After using the above sampling method, a decision on treating a crop for green mirids depends on the numbers found after sampling six sites per field. Growers may not be able to solely rely on heliothis egg parasites to control late season larvae. However, they contribute to a fully integrated pest management program

Development of sustainable, efficient, integrated weed management systems for cotton production is the primary goal of the weeds programs (CRDC and CRC funded). This goal is being achieved through a range of approaches including determining a base level for weed management in the cotton industry, scientifically evaluating a range of alternative weed management strategies including different herbicide combinations and rates, alternative herbicides with transgenic, herbicide tolerant cotton varieties and alternative cultivation and stubble management practices, and developing specific weed management packages for difficult to control weeds. This project has furthered the weeds goal in all aspects. An important highlight has been the development of a management strategy for nutgrass. Preliminary field evaluation of a range of weed management options including normal and transgenic cotton has also been undertaken. Work over the next 3 years will examine options for peach vine management, and management options with stubble retention.

The objectives of the project were (I) to evaluate potential biocontrol agents for seedling disease control, (2) to evaluate potential biocontrol agents for the control of Verticillium wilt of cotton and (3) to develop and compare strategies for the biocontrol of Verticillium wilt. It was also proposed that some preliminary work would be carried out to investigate the feasibility of biocontrol methods for the control of black root rot, Fu sari um wilt and Galathera syndrome. A major development in the course of the project was the shift in the emphasis from research on biocontrol of Verticillium wilt to that on biocontrol of Fusarium wilt. By the 1995-96 cotton growing season it was clear that the varietal resistance was working effectively against Verticillium wilt. Fusarium wilt, although largely confined to Queensland, was becoming a concern to the NSW and Australian cotton industry.

The results of disease surveys have indicated a declining incidence of Verticillium wilt and seedling diseases and an alarming increase in the prevalence of Fusarium wilt, black root rot and Alternaria leaf spot. Bacterial blight and Alternaria leaf spot have become significant problems for Pima growers in the Bourke area

This project helped to identify the factors that affected the efficacy of transgenic Bt cotton plants to control Helicoverpa punctigera and H. armigera. This knowledge contributes the design and refinement of the resistance management strategy for the commercial use of transgenic cotton plants

This project aimed to estimate the capacity of Helicoverpa armigera to develop resistance to INGARD cotton, to examine the possibility of cross-resistance to other Bacillus thuringiensis (Bt) toxins and to elucidate the mechanism(s) underlying that resistance. We have used several approaches to selecting H. annigera for resistance to CrylAc, the toxin expressed by INGARD cotton. This involved presenting the toxin in two different formulations and selecting insects for the next generation on two different criteria. By the end of the current project we were seeing the beginning of resistance in at least two distinct selection lines. The slow rate at which H. armigera developed resistance is encouraging for the industry but has delayed our investigation of cross-resistance and mechanisms. In parallel with the selection experiments we investigated the potential of various factors to increase the toxicity of Cry1Ac. We have tested the interactions between Cry1Ac and different Bt toxins, some proteinase inhibitors (to reduce the degradation of the toxin), and chitinase (to provide the toxin easier access to the midgut epithelium). There was no interaction between Cry1Ac and Cry1Ab or other Bt toxins that have very slight toxicity for H. armigera. Surprisingly, the two most potent toxins (Cry1Ac and Cry2Aa) proved to be antagonistic, although only slightly so and this antagonism is not expected to be evident in pyramided plants. Although the proteinase inhibitors and chitinase showed some effects on growth rate of H. annigera, the effects were not large enough to be useful.