Molecular approach to insecticide resistance development and monitoring in potato insect pests

Project code: PRR03-460

Project Lead

Yvan Pelletier - Agriculture and Agri-Food Canada

Objective

To develop a molecular diagnostic tool which will allow potato producers (through an agricultural pest monitoring service) to track resistance to insecticides in their fields

Summary of Results

Across North America, including the Canadian Atlantic provinces, instances of potato insect pests which have become resistant to synthetic pesticides have been documented. The failure of an insecticide to control a pest can cause significant economic losses for potato producers and result in unnecessary loading of pesticides into the environment; therefore, resistance management is an important aspect of any pesticide risk reduction strategy. The only test available currently to gauge the level of resistance in a pest population must be conducted immediately prior to the normal spray date, by which time the grower has already purchased pest control products. It is thus of little practical help to the farmer.

Because the most common mechanisms of resistance development come about through genetic point mutations, a PCR-based molecular approach was used to analyze pest population DNA for changes (mutations) to genes known to be involved in insecticide detoxification or alteration of insecticide target sites. Examples of some of these genes are: cytochrome P450, glutathione-S-transferase, esterase, and nicotinic acetylcholine receptor.

A new method to monitor the development of resistance in pest populations was developed based on this molecular approach. Further validation of this resistance monitoring tool is underway, and a commercial partner to develop the tool is being sought. At the same time, the design of resistance management strategies has been advanced by the development of a DNA array tool which can be used by researchers to aid in discovery of insecticide resistance genes.

Both of these advances should improve resistance management at the field level, through improved and timely monitoring of pest populations to ensure producers do not use ineffective insecticides in their operations, and through discovery of new insecticide resistance genes for incorporation into monitoring tools in the future.

For more information, please contact Dr. Yvan Pelletier at the Potato Research Centre, AAFC, Fredericton, New Brunswick.

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