CABI - Biocontrol News and Information 25(4) December News

Biocontrol News and Information

December 2004, Volume 25 No. 4

IPM Systems

This section covers integrated pest management (IPM) including biological control, and techniques that are compatible with the use of biological control or minimize negative impact on natural enemies.

Checkmate for Italy's Fruit Pests

The location for the recent 6th International Conference on Integrated Fruit Production [see: Conference Reports, this issue] at Trento, part of the northern Italian region of Trentino-South Tyrol focused attention on the successful adoption of mating disruption by growers in the area to control lepidopteran pests in apple orchards and vineyards. The key to successful area-wide pheromone applications in the region is tight coordination of research, extension and industry - plus a zest for innovation and progress.

Vineyards

From a small beginning on the Piana Rotaliana of the Val d'Adige, pheromone-mediated mating disruption in vineyards has steadily gained ground. In 1990, the technology was trialled for control of grapevine moth, Lobesia botrana, on 14 ha of the Mezzacorona vineyards. By 2004, mating disruption was being implemented on 8600 ha, or almost 95% of the grape-growing areas of Trento (Trentino) province. During the early years the target was the grapevine moth, but since 1999 the European grape berry moth, Eupoecilia ambiguella, has also been targetted. Both are controlled with Isonet L+ in areas with extremely low incidence of E. ambiguella while Isonet LE is used where the two insects have an historical record of co-existence. Both dispensers are from Shin-Etsu Chemicals.

The Istituto Agrario di San Michele all'Adige (IASMA) (see below) and its extension service have been playing a key role, in collaboration with the Trentino Wineries Association, in this successful venture. By establishing proper scouting timing and thresholds, and organizing group applications, they have been able to reduce the insecticide input to Trentino vineyards from the 1980s average of 10-15 kg/ha down to zero.

Orchards

Codling moths (Cydia pomonella and Cydia molesta) are aggressive orchard pests, capable of achieving high population densities. At the beginning of the 1990s, growing resistance to chitin synthesis inhibitors such as diflubenzuron began to emerge in codling moths in South Tyrol (Bolzano or Alto Adige) province, where a strong orchard sector includes some 7000 growers. The limited efficacy of the organophosphate alternatives, together with demands from the strong local tourist trade for non-chemical options to be pursued, led to trials of pheromone-based control. Since then, it has become the control option of choice on some 78% of the apple-growing area with some 14,000 ha in South Tyrol and 1500 ha in Trento (in 2004). This advance has been made possible because data gathered over the last 12 years has helped to define the possibilities and limits of mating disruption. The crucial role of the extension service Südtiroler Beratungsring für Obst und Weinbau in fine-tuning treatments for local conditions brought new developments in the form of multiple species dispensers against, for example, mixed infestations of C. pomonella and C. molesta, and multiple species infestations of C. pomonella, C. molesta, Pandemis heparana and Adoxophyes orana.

In the final analysis, farmers have to make a living so pest control decisions have to make economic sense. What may limit the adoption of mating disruption is whether it is as cost-effective as several insecticide sprays. For this reason, more effective formulations and dispensers remain key areas for research, together with strategies to combat multiple species infestations. Another key issue is technology-transfer support and education to improve orchard scouting and mating disruption application accuracy.

IASMA and SafeCrop Research

IASMA has been a driving force in the adoption of pheromone-mediated mating disruption to control orchard and vineyard pests in Trentino-South Tyrol. The institute has a long history, having started life in 1874 as an agrarian school and experiment station. It now promotes and carries out research, education and training activities as well as providing technical assistance and services. Its remit is to promote cultural and socioeconomic growth in the agricultural sector and to develop forestry and agro-food systems, while safeguarding the environment and land.

IASMA also hosts the SafeCrop Centre, a network of international institutes focusing on research and development of sustainable crop protection with low environmental impact with the aim of reducing chemical inputs in agriculture. One strand of SafeCrop's innovative application-oriented research is directed at resolving the constraints to widespread adoption of these strategies, including lack of reliability of impact, high costs of product registration, and the need for measures to be adapted for local and crop specific characteristics and therefore small marginal markets. As the policy of the centre is to develop sustainable, low- or zero-impact control strategies, a second research strand is oriented towards questions such as unwanted side effects, and investigating possible environmental and food contamination by agents employed in its low-impact strategies.

The SafeCrop Centre houses three research units covering insect and microbial biological control and risk assessment, and their research is focusing on grapes, apples, strawberries and other small fruit and horticultural crops. Initiatives, some in collaboration with IASMA, include:

Flying doctors: studies on the distribution and colonization of apple flowers by a bacterial biological control agent vectored by bees (collaborators: ETH-Zurich, Switzerland)
Firefight: (a) risk prognosis systems for fire blight of pear and apple (collaborators: FAW, Wädenswil, Switzerland and ARO, Israel) and (b), field testing the efficacy of biological control agents for fire blight (collaborators: BBA-Darmstadt, Germany)
Cydia molesta: developing biological control through mass-rearing and inundative release of a parasitic insect (collaborators: ETH)
Powdery mildew of strawberry: developing microbial biological control agents for integrated control of this significant fungal disease which currently needs a high fungicide input
Biological control agents - cross-effects: investigating reduction in codling moth oviposition by biological control agents used against fungal diseases (collaborators: Volcani Centre, Israel and INRA-Versaille, France)
Biological control agents - R&D risk: R&D of microorganisms with potential as biological control agents can carry various risks to both the researcher and the environment. This project analyses the R&D processes with the aim of proposing protocols to allow risks to be identified and minimized.
Pheromones - hail-nets: protective nets are frequently used by apple growers in this region, where hail damage that slashes the value of the crop occurs in many years; this project aims to identify what, if any, differences the use of hail nets makes to concentrations of pheromones, and what significance this has for codling moth control (collaborators: Lund University, Sweden and Shin-Etsu, Japan)

Contacts: Vittorio Veronelli,
CBC (Europe) Ltd - Milan, Via E. Majorana 2,
20054 Nova Milanese (MI), Italy.
Email: vveronelli@cbc-europe.it
Fax: +39 0362 41273
Web: www.cbc-europe.it

Claudio Ioriatti, Cesare Gessler & Ilaria Pertot, IASMA / SafeCrop Centre, Via E. Mach,
I-38010 San Michele TN, Italy.
Email: claudio.ioriatti@iasma.it,
cesare.gessler@ismaa.it or ilaria.pertot@ismaa.it
Fax: +39 0451 650 872
Web: www.ismaa.it

Regulation and Science of Biopesticides

Filling some gaps in understanding biopesticides is the subject of a new UK research project. The project draws on the strengths of the University of Warwick's biologists and social scientists, and builds on the new status of Warwick HRI (Horticulture Research International) as part of the University of Warwick. A joint team from Warwick HRI and the university's Department of Politics and International Studies is being funded by the Research Councils UK Rural Economy and Land Use programme to investigate economic and scientific issues in biopesticide development.

The relative failure of biopesticides to gain a significant share of the world crop protection market (with the exception of Bt, or Bacillus thuringiensis) has been at least partly blamed on lengthy and expensive regulatory processes. In the UK, there has been poor uptake of microbial biopesticides, much of the development has been initiated in the public sector. It has then been taken up by small-and medium-sized companies who have been discouraged from taking a final product to market because of the prohibitive costs of the registration fee and associated data package. Professor Wyn Grant will probe how the UK pesticide regulatory system, built around the use of chemical insecticides, impacts on the development and use of biopesticides. The chemical regulatory model focuses attention on the short-term economic costs of pest control measures rather than their long-term impact on the environment and the sustainability of farming systems. Biopesticides have potential to bring long-term environmental protection and social benefits and any regulatory innovation that would take proper account of such innovations would be a significant spur to their future development. Professor Grant's study of UK pesticide regulation will include a comparative study with the legislation based pesticide regulation framework in Denmark.

A better scientific understanding of the operation of biopesticides, and in particular their impact on the sustainability of pest management, is clearly also needed if the regulatory climate is to be altered. Dr Dave Chandler will look at whether biopesticides persist in the environment when released on a large scale and how they interact with local microbial populations. For his study he will use as a model system the entomopathogenic fungus Metarhizum flavoviride as a biopesticide against aphids on lettuce.

Contact: Professor Wyn Grant,
University of Warwick, Department of Politics
and International Studies.
Email: w.p.grant@warwick.ac.uk

Dr Dave Chandler, Warwick HRI,
University of Warwick.
Email: dave.chandler@warwick.ac.uk

No Match for the Birds

Two wrongs can make a right. At least, that is what they are hoping on the UK Channel Island of Guernsey, where increasing populations of may bugs or cockchafers (Melolontha) have been causing damage to amenity grass over the last 6 years. The larvae feed on the plant roots and in large numbers they kill areas of grass. This year saw a new twist. Areas of the grass on a school playing field were completely destroyed by seagulls tearing up the grass to get at the larvae feeding on the roots.

Now amenity managers are hoping to turn the birds' taste for may bug larvae to their advantage. They want to remove as many larvae as possible before they re-seed the playing field. They have devised a plan to rotivate the field regularly to expose the pests, which they hope the seagulls will gobble up. If this works, they will have a smaller may bug population in the field next year, so both direct damage and bird damage will be reduced.