This report presents the experimental works and outcomes of my study on the project “IPM

in BollgardII® cotton‐New tools and strategies: A Farming: Systems Approach” under the

agreement between NSW Department of Primary Industries and Cotton Research and

Development Corporation (Project DAN 179C). The project has refined current tools and

developed new tools and strategies to complement beneficial insect’s activities in support of

IPM program on BollgardII® cotton crops as part of a continuous improvement to the

industry’s IPM system.

The aims of this project were:

1. Determine the efficacy of Petroleum spray oils (PSOs) as a stand alone product for

activity against green mirids and aphids;

2. Determine the efficacy of PSOs as adjuvants for full and reduced label rates of synthetic

insecticide for activity against Helicoverpa spp. and green mirids;

3. Assess the effect of PSO residues and sprays on the survival and rate of consumption of

cotton pests by predatory insects in Bollgard cotton crops;

4. Determine and compare abundance of green mirids on Bollgard crops interplanted with

and without lucerne strips or placed adjacent to lucerne blocks or refuge crops

interplanted with lucerne strips;

5. Evaluate the efficacy of a new myco‐insecticide for activity against green mirids on

Bollgard cotton crops;

6. Determine strategic use of Magnet (moth) attractant on Bollgard II® cotton crops on the

level of Helicoverpa spp. production and management on conventional cotton crops

7. Determine strategic use of Magnet (moth) attractant on Bollgard II® cotton crops and

PSOs on conventional cotton crops on the level of Helicoverpa spp. production and

management of Helicoverpa spp. on the conventional crops

8. Assist in the review of the cotton industry IPM guidelines.

To achieve these aims a series of laboratory, mesh house and large scale field experiments

were conducted in irrigated commercial cotton crops in the lower, Gwydir and Macintyre

valleys in New South Wales and Queensland between July 2004 and June 2007. Plot sizes

ranged from 3 to 400 hectares.

In studies to assess the efficacy of Petroleum spray oils as a stand alone and in mixtures with

reduced rates of synthetic insecticides, the results showed that application of 2% v/v PSOs

by themselves can cause direct mortality to Helicoverpa spp. larvae particularly 1st ‐3rd instar

stages and green mirid adults and nymphs. The addition of 2% v/v of either Biopest or

Canopy® oil to ½ rate insecticides achieved similar control of Helicoverpa spp and green

mirids as 1% PSO + full label rate insecticide and also the full label rate insecticides alone. In

terms of conservation of predatory insects in the cotton cropping system, the application of

PSO mixed with ½ label rate of insecticides minimised the impact of the insecticides on

beneficial insects compared to the full label rate or 1% plus the full label rate of the

insecticides. The prey consumption rate of the predators that survived PSO sprays alone or

in combination with reduced rate of insecticides was not affected.

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In the study to assess the use of trap crops to manage green mirids on BollgardII® cotton

crops, the results showed that green mirids prefer sunflower and lucerne to cotton crops.

However, sunflower dries off in January when cotton plants are in their peak squaring,

flowering and boll setting stage. The drying of the sunflower crops will force green mirids to

move to the cotton crops to cause damage and yield loss. In contrast, lucerne crop has a

permanent growth and can maintain the mirids throughout the cotton growing season

provided the lucerne is kept fresh by watering. The study showed that lucerne crop can trap

and manage green mirid numbers in adjacent BollgardII® cotton crop to a distance of 250‐

300 metres away from the lucerne crop.

One of the most significant and major breakthroughs in this project is the development of

two fungal insecticides (BC 639‐Metarhizium spp and BC667 – Beauveria spp), for the control

of green mirids, Helicoverpa and aphids. The result of the study showed that application of

0.5‐1.0L/ha of either fungus can cause over 70% mortality of green mired adults and

nymphs. In most field trials, application of BC639 and BC667 at rates of 0.5‐1.0 L/ha reduced

densities of green mirid adults and nymphs from 3.5 per metre to zero within 7 days after

treatment. The efficacy of the fungal insecticides applied at these rates against green mirid

adults and nymphs was the same as Fipronil applied at the label rate.

The fungus killed green mirids within 3‐4 days after application. The fungus is selfperpetuating

and can cause secondary infection to green mirids whereby the death of

infected mirid or insect can produce spores which will then infect and kill live insects. The

fungus is effective against soft bodied insects (mostly pests) so that hard bodied insects

(mostly key predatory insects) are often saved. In field trials, I found no significant

differences between the number of predatory beetles, bugs, lacewings and spiders per metre

in plots treated with fungal insecticides and unsprayed (control) plots. In contrast, the

number of predators recorded on plots treated with the fungal insecticides was significantly

higher than the commercial insecticide (Fipronil). This indicates that the fungal insecticide is

“softer” than Fipronil.

A Commercial partner has been identified and a commercial agreement between the Cotton

Research and Development Corporation, NSW Department of Primary Industries and the

Commercial partner will be signed on 29 February 2008.

In studies to determine the strategic use of Magnet® (moth attractant) mixed with

insecticides to attract and kill Helicoverpa moths on BollgardII® cotton crops, the study

showed that the Magnet® formulations killed Helicoverpa spp. (moths) resulting in reduction

of Helicoverpa moth populations on adjacent conventional cotton crops located 0.5 to 1 km

away from the “treated” BollgardII® cotton crops. This strategy resulted in a pest control

saving of $11.40 per ha in the “treated” over the “untreated” conventional cotton crops.

The study also showed that application of Magnet® formulation onto the Bollgard cotton

crops attracted moths from the environment to the treated area and the residual moths that

could not reach the Magnet® treated zone before the Magnet® odour dissipated stayed in

the conventional cotton crop that was closest to the “treated” BollgardII® crops and laid

eggs. By applying Petroleum spray oil (PSO) on the conventional cotton crops, the number

of Helicoverpa moths, eggs and larvae per metre on the conventional cotton crops treated

with PSO was significantly lower than the conventional cotton crops not treated with the

PSO. The explanation given was that application of PSO on the cotton plants suppressed the

quantity of airborne volatiles released by the cotton plants resulting in lower egg and larval

numbers on the PSO‐treated plants.

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The project also provided information and assisted in the review of the Cotton Industry IPM

guidelines in 2005. The IPM guidelines was launched by the Hon. John Anderson MP, and

Deputy Prime Minister of Australia on 18th February 2005. New information on the use of

PSO in managing pests on cotton, trap cropping and predator to beneficial insect ratio has

been incorporated into the guidelines.

Overall, the project has developed two new IPM tools (BC639‐ Metarhizium spp. and BC 667

– Beauveria spp) for the control of green mirids, Helicoverpa spp. and aphids. The project has

also developed other alternative pest control tools (lucerne strips, Petroleum spray oils ‐ as

stand alone and adjuvavants with reduced label rates of insecticides) as additional tools for

the industry’s IPM program. The project has also developed management guidelines for use

of lucerne strips, PSOs and Magnet (moth) attractants for cotton growers to manage both

their Bollgard and conventional cotton crops. Thus, the project has addressed the issue of

sustainable use of pesticides in the cotton industry.

The project has linked with Industry Development Officers (IDOs), reseachers and

consultants to provide information and refine the cotton IPM guidelines.

In conclusion, the project has been very successful in developing two new biopesticides

(fungi) that can be used by cotton growers to control green mirids, Helicoverpa spp. and

aphids. Other major project outcomes include enhancement of IPM programs on both

transgenic and conventional cotton, reduction of insecticide sprays, delay insect resistance to

synthetic insecticide and transgenic cotton and improve profitability, competitiveness and

sustainability of the cotton industry.