CABI - Biocontrol News and Information 19(1) March 1998 News

Integrated pest management (IPM) involves the use of many techniques, including biological control, to provide effective control of crop pests with minimum harmful side-effects. Those techniques which are compatible with the use of biological control or have little impact on natural enemies have been described as `biorational'.

World Bank staff have agreed that their existing policy on pest management should be revised to reflect the importance of farmer-driven, know-ledge-intensive and ecologically based approaches. The Bank staff made this commitment at a meeting in October 1997 in Washington DC with staff from the Pesticide Action Network (PAN) North America, the Consumers Union's Consumer Policy Institute (CPI), the Environmental Defense Fund (EDF) and several other non-governmental organizations (NGOs), just short of a year after a letter signed by over 180 NGOs and concerned individuals addressed to the World Bank protested at the drastic weaken-ing of its pest management policy.

In 1996, research by PAN, CPI and the Bank's own evaluations indicated that rather than promoting ecological alternatives to toxic pesticides, the Bank was more often than not ignoring the findings of its own environmental impact assessments, while approving hundreds of millions of dollars in loans for pesticides on a regular basis. A joint NGO letter criticized the Bank for failing to take a stand on reducing borrower countries' reliance on chemical pesticides in Bank-funded projects and emphasized the abundant proof that effective national policies and programmes can be built upon farmers' education, innovation and development of these alternatives. The signing groups wanted to see the Bank follow the example set by farmers, NGOs and governments around the world, and by agencies such as the Food and Agriculture Organization of the UN (FAO).

At the meeting in October 1997, Bank staff agreed to: include in the revised integrated pest management (IPM) policy a commitment to reduce reliance on chemical pesticides in Bank-funded projects; recommend revisions in the Bank's 1996 IPM policy to reflect the importance of farmer-driven, participatory and ecologically based approaches; and finalize the establishment of a new full-time IPM specialist position. While much remains to be done, advocates of farmer-driven ecologically-based IPM had achieved a number of successes at the Bank by the end of 1997. In the coming year, PAN and partner NGOs will continue to pressure the World Bank to transform these recent policy concessions into actual improvements in the lives of farmers around the world.

Source/contact: Pesticide Action Network North America (PANNA), 116 New Montgomery, #810,
San Francisco, CA 94105, USA
[E-mail: ]
Fax: +1 415 541-9253
Internet: http://www.panna.org/panna/

A strain of Metarhizium anisopliae (code "I 1045" by Dr Richard Milner of the Commonwealth Scientific and Indust-rial Research Organisation - CSIRO) is being developed as a biopesticide for control of the larval stages of greyback canegrub, Dermolepida albohirtum. The fungal disease was isolated from greyback grubs collected from a canefield in Tully, far north Queensland in 1993, and has been extensively tested against the cane pest over the past four years by Dr Les Robertson of the Bureau of Sugar Experiment Stations (BSES). Greyback canegrub is the major root-feeding pest of sugarcane in Australia, and strains of the same species of fungus have been used to control grubs of other beetle pests in pasture and cereal crops in Australia. One product, BioGreen TM, is registered and is being sold for use against the red-headed cockchafer, Adoryphorus couloni, a turf and pasture pest in Tasmania and Victoria.

The Metarhizium material was massproduced as sporulated product on sterilized rice by Bio-Care Technology Pty Ltd and evaluated at a wide range of application rates, both in recently planted cane and in ratoon cane after harvest. The trial work by BSES staff and CSIRO is funded by the Sugar Research and Development Corporation with considerable assistance from co-operating canegrowers.

When applied in a band in the soil along the row of recently planted crops, an application rate of 33 kg/ha of the rice-based formulation has given about 50% control of canegrubs before the period of severe root pruning in cane crops. In subsequent ratoon crops, the level of control increases with about 70% of grubs dying of Metarhizium by the mid-stage of their development. Grubs continue to die of Metarhizium throughout the later period of grub development but the aim is to prevent severe damage to cane. Levels of control increase marginally with higher application rates, but the higher rates may not be economic. Where grub infestation levels have been high, treatment of the plant crops with Metarhizium has given significant increases in cane yield and sugar production, and has also allowed the ratooning of cane for subsequent crops. Treatment of ratoons has not been successful because of the difficulty in placing sufficient Metarhizium in the root zone of established crops.

In 1997, approximately four tonnes of the experimental product was applied over 45 sugarcane farms in north Queensland under an experimental use permit from the National Registration Authority (NRA) to evaluate its commercial potential.

Contact: Dr Les Robertson, Senior Entomologist, Bureau of Sugar Experimental Stations, Tully, North Queensland, Australia.

Light After Bt?
Scientists at the University of Madison (Wisconsin, USA), working in collaboration with DowElanco (Indianapolis) have identified a bacterium living in the gut of entomopathogenic nematodes which they say may prove as effective as Bacillus thuringiensis (Bt) against insect pests. The bacterium, Photorhabdus luminescens, contains a toxin that has been shown to be effective against a broad range of insect pests, from cockroaches to boll weevils.

The toxic potential of P. luminescens, a widely-dispersed, multiple strain bacterium that lives in the gut of, and in symbiosis with, soil-dwelling nematodes that invade insects, was characterized by bacteriology professor Jerald Ensign and student David Bowen. Once inside an insect host, the bacteria are released from the nematode, kill the insect, and set up rounds of bacterial and nematode reproduc-tion that turn the insect into a `protein soup', food for large numbers of nematodes. And the corpses left behind by the bacteria glow in the dark as the microbe produces luminescent proteins in addition to potent insecticides.

As a post-doctoral fellow in the Entomology Department headed by Richard ffrench-Constant, Bowen then worked on the biochemistry of the toxin and orchestrated a nationwide survey for toxic strains of the bacterium. Scores of new strains have been recorded, and it has been found that each produces its own variation on the toxin. The Photorhabdus toxin and the genes that produce it have been patented jointly by the Wisconsin and DowElanco scientists through the Wisconsin Alumni Research Foundation (WARF). The technology has been licensed to DowElanco.

In concentrated doses, the toxin can be used as a spray or fed directly to insects, but the greatest potential application is seen to be in transferring the toxin-producing genes from the bacteria to crop plants. Bowen, working with Thomas Rocheleau and Michael Blackburn in ffrench-Constant's laboratory has identified, cloned and sequenced the genes responsible for the Photorhabdus toxin, and clones were also independently derived at DowElanco. The next step to move those genes to any amenable crop plant is well underway, but bringing a product to the field may still take anywhere from three to five years, says ffrench-Constant.