The insecticide, endosulfan, is still an effective weapon in the arsenal against Hellothis pest species. It fs used extensively in spring and summer as a cheap alternative to the synthetic pyrethroids. This is despite the recurrence of endosulfan resistance first observed in the 1970's (Kay et aL 1983). According to the monitoring data obtained by Neil Forrester ( 1992), NSW Agriculture & Fisher1es, endosulfan resistance was present at levels of 10- 30% in the Namoi Valley during years 1986-1989. However, in the past two years resistance has undergone a sudden increase, with frequencies of up to 50% during summer. A similar pattern was observed in Emerald, although resistance frequencies are higher than in the Namoi Valley (Forrester 1992).

The Cotton Research and Development corporation (CRDC) is funding a comprehensive 3-year project to discover the environmental fate of endosulfan sprayed on cotton for insect control. Experience overseas suggests that endosulfan is in quite a different class to organochlorines like DDT, rarely if ever accumulating in soils or flora and fauna. However, apart from the routine testing performed by the manufacturers, there was no independent data on the fate of endosulf an under Australian conditions. This project was funded by CRDC to overcome this lack of data.

The suspected importance of pyrethroid metabolism in resistant H.armigera. made the investigation the biochemical basis of pyrethroid resistance in H. armigera imperative. In this background paper, we summarise our findings.

It has been 9 years now since the introduction of the Summer Crop Resistance Management Strategy in 1983/84 season. This voluntary Strategy has been well accepted by all segments of the industry and has underpinned the development of the thriving rural success story that is the Australian cotton industry.

A change of direction for entomoLOGIC and some improvements to hydroLOGIC will provide growers and consultants in the 1992/93 season with effective, low cost decision support systems for irrigation and pest management. These improvements have been brought about by feedback received from growers and consultants who have used the packages in recent seasons.

The reliance of the Australian cotton industry on insecticides for the control of insect pests represents a major economic and environmental concern. In the face of pesticide resistance in H. armigera and increasing environmental problems associated with pesticide use, the development of cotton varieties with enhanced resistance to pests, particularly Heliothis and mites, is a major objective of CSIRO to help lessen dependence of the industry on chemical pesticides. Both conventional breeding and genetic engineering are being used to produce pest resistant cottons. Here we discuss work to compare the levels of pest resistance in a variety of cotton cultivars which bear either morphological, or biochemical factors for resistance and to identify characteristics which may be valuable for incorporation in the highly successful breeding program at Narrabri

In the 1991/92 season we started observations in both sprayed and unsprayed plots of different cotton varieties to record the numbers of fruit lost during the season and to identify the causes of shedding. The first years results are presented here.

The importance of Heliothis has grown with the advent of resistance in H.armigera to various pesticides. This, coupled with increasing public concern about the use of pesticides, has meant that the cotton industry needs to find alternative forms of control. One of the potential alternatives is mating disruption. This is achieved by releasing into the atmosphere sufficient amounts of pheromone to disrupt communication between the sexes, preventing mating and subsequent egg laying.

There are, few parasitoids which specifically attack the pupal stage. This is perhaps understandable since pupae are not readily accessible, being in the soil. For the last few seasons we have been conducting a study of the biology, behavior and field ecology of a true pupal parasitoid of Helicoverpa, the ichneumonid wasp, Ichneumon promissorius. The aim was to assess the impact of the wasp on pupal populations of Helicoverpa spp. and to assess the possibilities for mass rearing it as a biocontrol agent, particularly for management of overwintering pupae in cotton areas. Here we give a brief account of the biology of I. promissorius and provide a summary of the abundance of various parasitoids in Helicoverpa pupae collected in the Namoi/Gwydir area over the period 1987-1991.