Improving Biocontrol of Diamondback Moth

The diamondback moth, (Plutella xylostella ; DBM) is the most cosmopolitan of pests and has spread, in part naturally by wind aided movement, and by the hand of man, to all those parts of the planet where crucifers are grown as crops or exist as wild plants. It is resistant to many pesticides and some biologically based toxins. Hence biological control has been used both as a component of IPM programmes designed to manage Plutella and on its own to reduce DBM populations to an acceptable level. The results have been varied, with good success in some areas and complete failure in others. How can the biological control of DBM be improved? A global problem caused by a pest equally damaging in developed and developing countries merits a global approach.

The Symposium `Improving Biocontrol of Plutella' sprang from an idea put forward by Garry Hill (formerly with CABI Bioscience, now at HortResearch, New Zealand), and Dominique Bordat of CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement) in 1999. Sixty-one delegates from 25 countries attended the CIRAD/US Department of Agriculture International Symposium held in the southern French town of Montpellier on 21-24 October 2002.

The organization of the Symposium was somewhat unusual. After a day and a half of talks by keynote speakers on the current status of Plutella in different parts of the world, pathogens as biocontrol organisms, classical systematics of parasitoids, the importance of polyDNA viruses in the pest /parasitoid relationship, and results of characterization of DBM and its natural enemies, everyone took part in a one-day workshop `Develop and Prioritize the Major Research Questions Concerning Improved Biocontrol of DBM.'

Participants were divided in advance into five groups of ten people. Each group consisted of a geneticist, an entomopathologist and an ecologist, a mix of nationalities, a bilingual speaker and facilitator to moderate the group discussions. The relaxed surroundings enabled participants to express themselves freely and strongly on matters regarding the improvement of biological control of Plutella.

Recommendations included improving taxonomic methods using on-line keys and genetic characterization, improved exchange of information, and dependable methods for rearing and applying biological control agents. A report on the workshop sessions will constitute one chapter in the book of keynote contributions due to be published and sent free to all registered colleagues.

The meeting attracted ten posters from Africa, seven from Asia, three from South America and Europe respectively, with two each from Oceania and North America. The quality and content of the posters was very high and many were from areas little represented at mainstream meetings.

The organizers thank the Director of the CIRAD La Valette campus for facilities. They also thanks the Scientific Committee and Horticultural Department of CIRAD (Flohr), the Region of Languedoc Roussillon, INRA (Institut National de la Recherche Agronomique) and the USDA Agricultural Research Service for financial support.

By: Dominique Bordat & Alan Kirk

Source: CIRAD/Flhor, Montpellier, France
http://dbm2002.cirad.fr/en/welcome.html

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