Resistance Management News

Briefings:

Monoclonal Antibody Sales Forcast to Increase Dramatically - National Biological Impact Assessment Program

Industry News:

NSW Agriculture Video
The NSW Agriculture has just produced a video on the resistance management programme based at the Narrabri Agricultural Research Station. The video deals with the practical aspects of running a Heliothis armigera resistance monitoring programme and was made as an aid to familiarize visitors with the Research Station's activities.

For more information please contact: Neil Forrester Senior Research Scientist NSW Agriculture Myall Vale Mail Run Narrabri, NSW 2390 AUSTRALIA Telephone (067)99-1500 FAX (067)93-1186

Insecticide Resistance Action Committee (IRAC)
IRAC has met twice (Brighton, November 1992; Bruxelles, April 1993) under its new chairman, Jean Jacques Herve. Work continues to be concentrated upon monitoring, using reliable IRAC approved methods, and on devising and implimentating industry-wide use management strategies. The inclusion of resistance issues in EEC registration submissions also brings new implications to IRAC studies on resistance.

Pyrethroid Efficacy Group (PEG)
The group has published a set of resistance management principles in the US. These principles were presented at the Beltwide Cotton Conference in January 1993 and will be published in the "Cotton Grower Magazine". These principles are enshrined in the following:

• Always include any efficient cultural/biological control practices in your pest control program.
• Time the application of insecticides against the most susceptible life stages based on local pest thresholds.
• Do not rely on a single insecticide class.
• Use insecticides at recommended rates and spray intervals.
• When there is more than one generation of insects, use different classes of insecticides in alternation.
• In the event of a control failure due to resistance do not respray with an insecticide of the same class.
• Ensure mixture components of different classes of insecticides are used at effective equivalent control rates.

The group continues to monitor resistance in Heliothis virescens and Heliothis zea in the US. This will be the seventh consecutive year of this monitoring using the adult vial test. This work is complimented by an IRAC sponsored study on resistance mechanisms (J. Ottea, Louisiana State University).

Last season monitoring revealed low levels of resistance pre season which increased under insecticidal pressure and continued moderate increases in late season.

Following on from a conference on resistance in Beijing (March 1993) a PEG China group was formed to coordinate industry actions towards the management of Heliothis armigera and Aphis gossypii on cotton.

Cotton Working Group
IRAC method number 7 (leaf eating larvae of Lepidoptera and Coleoptera on cotton, vegetables and field crops) has been approved following testing and with some modifications was used extensively in Pakistan during the 1992 season. A recent meeting in Seville, Spain, resulted in a useful discussion of resistance issues in Spain although it was not appropriate to inaugurate an IRAC Spain group.

Data on insecticide resistance in cotton from 25 countries is now available.

The USA group is sponsoring a study of methods and strategies to combat resistance in whitefly, as well as work on Heliothis virescens at LSU and USDA. The IRAC Cotton Mexico group has conducted a survey of Heliothis resistance and found largely susceptible populations. The data generated by IRAC Cotton Pakistan in 1992 is currently being analyzed. There are indications of moderately multiresistant populations in some areas.

Fruit Crops Working Group
The Spider Mite Resistance Management Strategy developed by the group (P. Leonard in "Resistance 1991, achievements and developments in combatting pest resistance"; see also G. Sterk and P. Highwood, Brighton Crop Protection Conference, Pests and Diseases, 1992, 517-526) is being publicized in order to maximize its impact on growers. Resistance management guidelines for Myzus persicae are being developed. In order to evaluate the risk of cross resistance and develop use management strategies prior to introduction, a research project using 4 novel acaricides in various stages of development is being planned.

Field Crops Working Group
Sponsored research by Edward Cheng in Taiwan validated the use of IRAC Method No 7 for Plutella and found no apparent cross resistance between acyl urea IGRs and other chemical groups. The group is currently gathering information on the resistance status of Colorado Potato Beetle in E. Europe and plans to collaborate with the Fruit Crops group on Myzus persicae.

Bacillus thutingiensis (Bt) Working Group
This international group of 13 companies has funded a large number of projects addressing the questions of the potential for resistance development and use of management strategies. This approach is in order to have a strategy prior to the reports of resistance, as it should be noted that outside of the laboratory, only one isolated case of Bt resistance exists, in a situation of extreme pressure. Priority is being given to finding reliable monitoring methods.

Public Health Working Group
A joint meeting with WHO was held (Geneva July 1992) to discuss resistance strategies in Anopheles control and plan future work.

At a WHO ministerial conference on Malaria (October 1992) a statement was made that any increase in the spread of malaria was not due to any technical problems associated with anolpheline control but resulted from management constraints and limited resources. Industry looked forward to working with international agencies and governments in new initiatives to control malaria.

Stored Products Working Group
Continuing concern over the misuse of fumigants and specifically phosphine have led to the planning of a workshop session at the forthcoming 6th International Conference on Stored Product Protection (Canberra Australia). Methods for resistance monitoring of stored product pests are being examined.

EEC Registration
Following the inclusion of resistance risk assessment and management strategies in the draft harmonized EEC regulations for registration of technical material and formulated product, IRAC together with HRAC and FRAC have issued a response to ECPA on the proposed regulations, which has been submitted to the EEC commission. This combined "RAC" view was based on the principles of resistance management and risk evaluation. At the time of writing, the combined "RAC" response has not produced any change in the proposed EEC regulations.

If you would like further information on any of the IRAC Groups or activities, please contact the author:

Stephen Irving
Communications Officer IRAC
DePont de Nemours (France)
Centro de Rocherche et Development
24 rue de Moulin
64740 Nambsheim
France

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