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.

This paper presents techniques used for rearing egg parasitoids on AGM eggs in an experimental facility at the QDPI Division of Plant Protection entomology laboratories in Toowoomba. These techniques have been adopted by commercial interests so that egg parasitoids can be reared in sufficient numbers for use by farmers for pest management in the future.

Recent research has indicated that two species of native egg parasitoids, Trichogramma (Trichogrammanza) carverae Oatman and Pinto and Trichogrammatoidea bactrae Nagaraja, have potential as biological control agents of heliothis (Scholz, 1990). This paper presents data on the foraging movements of T. carverae after release at a single point against heliothis in dryland cotton on the Darling Downs.

During the 1991-92 season, a 1 ha block of unsprayed raingrown cotton near Dalby was sampled for parasite activity in heliothis larvae. As the parasites of interest mainly attack small larvae (see Murray and Rynne 1992), parasitism levels were determined by weekly collections of third and fourth instars. A single release of about 200 female Microplitis demolitor Wilkinson was made on 17 January 1992 to supplement natural parasite activity. In this paper we present data on larval parasitism and discuss possible interactions between parasites and a recently discovered pathogen

Changes in Helicoverpa populations in non cropping areas

The aims of the project are to provide a basis for sound irrigation management of cotton through studies of: � (i) Crop response to a range of irrigation management options in terms of crop irrigation efficiency (yield per unit water applied) and plant fruiting development. (ii) Soil water balance in relation to irrigation application efficiency (infiltration per unit water applied), crop water use, ground-water accessions and model predictions of all these factors.

Objectives o Determine optimum nitrogen rates for cotton under a range of conditions. o Determine the best time to apply this nitrogen. o Measure the pattern of nitrogen uptake in relation to rate and timing and hence calculate fertiliser recovery. o Examine the relationship between soil nitrate test and subsequent nitrogen extraction by a cotton crop. Measure cotton crop requirements of the trace elements zinc, copper , iron and manganese . o Measure the effects of plant spacing, temperature and light on leaf growth in cotton. o Measure the penetration of light through cotton canopies . o Map the production and survival of cotton fruit. o Use the leaf growth, light interception and fruit map data to develop simulation models for cotton . Some success was achieved in all objectives . A summary of results from the major projects follows. More comprehensive results of all topics are attached. Difficulties encountered are outlined in the projects where they occurred.

Heliothis armigera and H. punctigera are serious pests of cotton in Australia. Control of Heliothis is currently dependent on insecticides. Levels of resistance to several of the major chemical groups of insecticides is sufficient to threaten the long ter

The project utilized a field trial established by Auscott Pty Ltd, on a grey-brown clay at Warren in June, 1984. The trial consists of 3 replicates of the following treatments: 1. deep ripping to 45 cm, followed by discing and listing; 2. chisel ploughing to 25 cm, followed by discing and listing; 3. direct listing only, ie. minimum tillage.

Project objectives To determine the nature and extent of migratory flight in Heliothis Armigera and punctigera and to estimate the significance of migration in the formation of outbreaks and in the spread of insecticide resistance in these pests.