Integrated pest management (IPM) is currently the most acceptable approach to pest control in the Australian Cotton Industry. The adoption of IPM in the cotton industry may be regarded as a continuous journey of discovery. Cotton growers are continuously learning about tools and strategies that can be used in IPM in order to minimise synthetic insecticide use. The introduction of Boilgard cotton crops will be a major boost and also a platform for IPM adoption in Bollgard cotton cropping systems. However, cotton growers will continue to grow conventional cotton crops alongside Bollgard crops as they learn more about the management of Bollgard crops for maximum yield and profitability. Subsequently, cotton growers will need new tools and strategies to manage pests on both Bollgard and conventional cotton crops with minimal synthetic insecticide intervention

Nuclear polyhedrosis virus (NPV) and Bacillus thuringiensis (Bt) are the most commonly used biopesticides for the control of Helicoverpa spp. larvae on cotton crops in Australia. These naturally occurring entomopathogens can regulate populations in agricultural and forestry ecosystems. However, in many instances, entomopathogens have not provided consistent control of pests to an acceptable level (Benz 1987) and in some cases yield loss has occurred (Mensah 2002). In Australia, NPV and foliar Bt are used to control Helicoverpa spp. on conventional cotton crops particularly early in the cotton season. The efficacy of NPV and Bt against Helicoverpa spp. larvae is often found to be inconsistent and can be inadequate when population pressure is high (Mensah 2002). This may be due to the narrow host range, retarded response and/or poor residual activity of biopesticides after application (McGuire 2000). Ultra-violet light (UV) is known to cause pathogens such as NPV and Bt to lose at least half their original activity within days of being applied in the field (Bull et al. 1976; Krieg et al 1980; Jeyakumar and Gupta, 1999). For these biopesticides to fulfil their role as effective, selective Iarvicides in cotton, it is essential that their persistence and efficacy be improved. Most studies aimed at overcoming the constraints of short persistence and low efficacy of entomopathogens, have focussed on the formulation of the pathogens, viz. fungi virus and Bt in oils within a biologically based framework (Inglis et al 2000). Oil based formulations has been reported to increase the adhesion of propagules to the insect integument, enhance spread of inoculum over the insect body, enhance penetration of the insect cuticle, protect propagules from ultra-violet radiation and enhance infection under low humidity (Ingris et al.2000). Recent research on citrus and a range of other horticultural crops led to the development of a PSO formulation which incorporated heavy base oil for maximum efficacy (Beattie et al. 1995, Beattie and Smith 1997) and UV light absorbing compounds to reduce the detrimental effects of UV light on unstable oil molecules. Minimising UV induced breakdown of the petroleum base oil can in turn reduce the potential of the PSO to damage plants (Hodgkinson et al 2002a; Hodgkinson et al 2002b). Further PSOs were developed based on this premise, to improve the effectiveness of UV labile biopesticides against cotton pests. The aim of this study was to determine the effect on persistence and efficacy of NPV and Bt of a UV protected PSO. The effect was measured by the control of Helicoverpa spp larvae, in relation to days after treatment application.

Petroleum spray oils (PSOs) are now an essential part of many integrated pest management (IPM) programs in agricultural crops (Beattie et al. 1995; Mensah et al. 1995). Despite these benefits, the use of PSOs has been limited in cotton due to a perceived risk of PSO-induced phytotoxicity and the fact that PSOs do not have a quick kill effect. Recent research on citrus and a range of other horticultural crops had led to the development of PSO additives such as UV light absorbers that can reduce the risk of phytotoxicity. The additives also enhance the persistence and activity of UV sensitive products such as biological insecticides to improve their efficacy and also can be mixed with synthetic insecticides to improve efficacy against a wide range of pests (see Mensah at al this proceedings; Beattie et al. 1995; Mensah, et al 1995; Jeyakumar and Gupta, 1999). The mode of action of PSOs appears to be multifaceted. Recent studies by Mensah et al. (2001, 2000) have shown that application of PSOs can affect Helicoverpa spp. egg lays on a range of host plants. Deterrence of oviposition by any compound or product against any pest should have a significant effect on the pests&#39 population by reducing the number of eggs deposited by pests on the plant leading to a reduced pest population (Hagen et al 1971). For cotton growers to utilize the oviposition deterrent activity of PSOs in their pest management program, they need to understand the mechanisms underlying the oviposition deterrent activity of PSOs. This will give growers a detail understanding of PSO use pattern effective against cotton pests particularly Helicoverpa spp. The aim of this study was to determine the mechanism that may be involved in the oviposition deterrence activity of PSO against Helicoverpa spp

Petroleum spray oils (PSOs) have been used for many decades to control a wide range of crop pests (Beattie et al 1995) and are known to have little impact on natural enemies of crop pests (Mensah et al 1995). They form an essential part of many integrated pest management (IPM) programs (Beattie and Smith 1997). Despite these benefits, the use of PSOs in the Australian cotton industry has been limited due to a perceived risk of PSO-induced phytotoxicity. In addition, since PSOs do not have quick knockdown effect like synthetic insecticides, growers do not consider PSOs as appropriate products to use against major cotton pests such as Helicoverpa spp. when their economic threshold is reached. However, historical research has shown that the risk of PSO-induced phytotoxicity can be minimised when a number of key base oil properties are considered in good practice PSO formulation. According to Johnson (1994) the use of a high quality base oil of no less than 91% unsulfonatable residues will ensure that few unsaturated compounds remain in the base oil to cause phytotoxicity. Subsequently, research on citrus and a range of other horticultural crops has led to the development of new PSO formulations, some containing UV light absorbers to eliminate photo-oxidation to further reduce the risk of phytotoxicity. Furthermore, there has been increasing evidence that PSOs similar to summer spray are appropriate for use in cotton to reduce numbers of Helicoverpa spp. eggs and to suffocate larvae (Mensah et al 1995; Liu and Stansly 1995). The insecticidal efficacy of PSOs is related to their viscosities (Johnson, 1994; Beattie at al 1995; Rae at al 1997 and Lui et al 2001). As a result there is a need to undertake studies using high viscosity oils for the management of Helicoverpa spp. on commercial cotton crops. The aim of this study was to determine the efficacy of high viscosity PSO and other crop oils as a stand-alone insecticidal product for activity against Helicoverpa spp. on cotton.

Trichogramma pretiosum Riley is an important parasitoid of heliothis (Helicoverpa spp.) eggs throughout the Darling Downs. In the past heliothis have been managed using broad spectrum insecticides such as pyrethroids and organophosphates. These insecticides usually cause high mortality of Trichogramma and other beneficial insects. Increasingly farmers and consultants are looking for soft chemistry to control pests without killing the beneficial arthropods in the farming system. Paraffin oils are now being explored as an option to control heliothis in cotton without causing high mortality of beneficial arthropods. Trichogramma are particularly sensitive to chemical insecticides and can act as bioindicators of the toxicity of insecticidal products. If an insecticide does not impact on Trichogramma it is likely that it will be conducive to most of the beneficial fauna in the farm ecosystem. This report documents the impact of two paraffin oils (Biopest' and Canopy') on Trichogramma pretiosum during larval, pupal and adult stages of development.

Trichogramma pretiosum is a key natural enemy of heliothis (Helicoverpa spp. ) on the Darling Downs. The data presented here describe some of the biological parameters of T. pretiosum, and may be useful in future population models that predict the impact of this valuable egg parasitoid on heliothis. Here we report on the lifespan, parasitism levels and progeny production of T. pretiosum reared on Helilicoverpa armigera in the laboratory.

There is increasing interest in utilising Trichogramma egg parasitoids against helothis(Helicoverpa spp. ) in cotton, and crops that may act as sources of parasitoids for cotton -such as sorghum. Very little has been published on the effect of different release rates ofwasps against helothis.Here we report on field trials evaluating different release rates of Trichogrommo pretiosumagainst Hencoverpa armigera in the sorghum and cotton at Evanslea on the easternDarling Downs.

There appears to have been a change in the importance of pests presenting cotton over the last decade. This has involved former secondary pests, such as aphids, A. gossypii, minds, Creontiodes spp. , green vegetable bugs, Nezara viridula (L. ), and whitefly, Bemisia tabaci (Gennadius), having attained greater prominence (Wilson 2002); relative pest pressures for these species are higher in B.t. than non-B.t. cotton (Doyle et al. 2002). The change in pest spectrum is likely to be a consequence of widespread adoption of IPM programmes (Wilson 2002). These sucking pests are a problem in IPM programmes, as broad-spectrum insecticide treatment is very disruptive to the beneficial arthropod fauna (particularly early-season applications), few narrow-spectrum insecticides are available, densities may flare following treatment with broad-spectrum insecticides (Wilson et al. 1998, 1999; SIosser et al. 2000), and little is known about the impact of their natural enemies (Wilson et al. 1998; Wilson 2002). As a consequence there is a requirement to determine the damage potential of a &#39new&#39 pest complex that contains several key pest species, not just a single species such as heIiothis, and for refinement of IPM programmes to better manage these pests. We conducted a season-long field trial better understand the impact of beneficial and pest arthropods, and to refine IPM programmes to better manage these &#39secondary&#39 pests. Treatments were designed to selectively manipulate beneficial and pest arthropod densities to enable examination of predator-prey relationships, and measurement of the relative impact of different beneficial and pest arthropod groups. We recognised two broad prey categories based on the mouthparts of the economically damaging life-stage; &#39chewing&#39 and &#39sucking&#39 pests. The chewing pest group predominantly comprised heliothis, the traditional major pest of cotton, while the sucking group comprised species formerly considered secondary pests, such as aphids, green mirids, green vegetable bugs and whitefly. These pest groups were managed alone or in combination using narrow-spectrum insecticides to supplement &#39natural&#39 mortality factors, although the treatments are &#39imperfect&#39 as the insecticides also reduced the abundance of beneficial arthropods.

Many beneficial arthropods exhibit life-history omnivory (Polis & Strong 1996), in that they include honeydew, floral nectar, extra-floral nectar and/or pollen in their immature or adult diet (Hagen 1986; Coll & Guershon 2002). Access to these resources may increase the abundance and rate of parasitism and predation by these arthropods. Carbohydrate and/or protein mixtures, such as Amino-Feed UV' Envirofeast' and Pred-Feed' can be applied to cotton crops to act as artificial supplemental food sources for beneficial arthropods. The rationale is to improve the synchrony of beneficial and prey or host populations in time and space (Hagen 1986) by one or more of the following: increased immigration and lowered emigration rates of beneficial arthropods (Evans & Swallow 1993; Evans & Richards 1997; Mensah 1997); consumption of the supplement by beneficial arthropods, leading to higher survival and/or reproduction (MCEwen et al 1996); higher parasitism or predation rates (Mensah & Singleton 1999, but see McEwen et al. 1996); and reduced number of eggs laid by pest arthropods (Mensah 1996). Field testing of artificial food supplements in cotton has focussed on targeting a few pest species (mostly heliothis), usually with multiple treatments (range I to 13) applied at 7 to 14 day intervals up until flowering or early boll filling growth stages (i. e. , until January or early February) (Mensah 1997, 2002a; Mensah & Singleton 2002). The early to middle part of the growing season was often targeted because pest densities were typically low to moderate (which leads to reduced application of disruptive insecticides), beneficial arthropods were perceived to effectively suppress these pest densities (Murray & Mensah 1996), and beneficial arthropod densities were thought to decline from January onwards, regardless of possible food supplement treatments (Mensah 2002a, b; but see Scholz et al. 2002). There is scope to extend the 'application window' of supplements to include a wider range of pest species over the entire season. This opportunity is the consequence of improved development and increased adoption of IPM programmes for cotton (Wilson 2002). It is imperative that proposed changes to the nature of artificial food supplement programmes are economically feasible. In this study we assessed the effectiveness of applying multiple treatments of an artificial food supplement (Amino-Feed UV') during the growing season to enhance beneficial arthropod densities. We measured beneficial and pest arthropod abundance, mortality rates of sentinel heliothis egos, fruit counts, crop yield and fibre quality.

Determining the impact of species considered potentially important natural enemies of crop pests is crucial for making robust management decisions as part of an IPM programme (Ives 1980; Johnson et al. 2000; Wilson 2002). Determination of prey species present in the diet of predaceous arthropods is an initial step in assessing their potential impact as biological control agents. Pacific damsel bugs are classified as 'generalist' predators, as they are known to feed on a large number of species from various taxonomic groups; 19 known arthropod species from 11 families in four orders are presently recognised as prey; including cotton aphids, Aphis gossypii, Glover, Heliothis, Helicoverpa armigera (Hubner), and mirids, Creontiades spp. Despite this, distinct biases are likely to exist for particular prey species. Measurement of the feeding rates of key predaceous arthropods on selected prey species, and elucidating the factors that affect this, is the next step in assessing their potential impact. Unfortunately laboratory tests tend to overestimate feeding rates by using artificially high prey densities; such results would not be applicable to field conditions without further testing. For example, the number of heIiothis eggs consumed by female Pacific damsel bugs, Nabis kinbergii Reuter, in 24 hours was reduced by 77, 74 and 92 % when caged on a single small, medium or large cotton plant, respectively, compared to a Petri dish (51.3 eggs per bug per day) (Johnson 1999). This suggests the ability of predators to find and consume prey is substantially reduced as the crop canopy expands and becomes more complex. A good approach to quantify the impact of predation by Pacific damsel bugs on arthropod pest densities is to combine a range of techniques, such as direct observation and cage inclusion studies. In this paper, we use glasshouse and field observations and glasshouse inclusion cage studies to determine the natural diet of the Pacific damsel bug, their feeding rates, and the influence of prey species, prey life stage and prey and predator density on these rates.