Development of reduced-risk strategies through coordinated monitoring, forecasting and risk warning systems for insect pests of field crops in Canada

Project Code PRR07-060

Project Lead

Owen Olfert - Agriculture and Agri-Food Canada

Objective

To develop and implement a region-wide monitoring program designed to 1) inform the industry on the economic risks to field crops from insect pests and 2) provide management recommendations based on pest risk and presence of pest natural enemies

Summary of Results

Background

The production area for field crops in Canada amounts to about 29 million hectare, with canola (approximately 5 million hectare) and grains (approximately 12 million hectare) being the major crops. Field crops are hosts to many insect pests which can cause up to 35% yield loss and multiple insecticide treatments are applied annually to control these pests. However, pest outbreaks can be cyclical and sprays may not be warranted if there is no actual risk of the pest being present in numbers to cause unacceptable economic damage. In addition, natural enemies may be present at sufficient numbers to provide some level of suppression for these pests. A region-wide pest monitoring and information delivery program was thus necessary to keep the agriculture industry value-chain informed of the actual risks from insect pests.

This project aimed at developing and establishing a coordinated network of monitoring sites across the Prairie Provinces to allow continuous tracking of key insect pests of canola and grain crops and their natural enemies, thereby enabling risk-based control recommendations taking into account the benefits of natural enemies of these pests.

This 3-year study represented a multi-organizational partnership across the Prairie Provinces and was part of a larger, 5-year project supported conjointly by Agriculture and Agri-Food Canada, Canola Council of Canada (CCC), Western Grains Research Foundation (WGRF), Provincial Canola Associations of Alberta, Manitoba and Saskatchewan, Provincial Departments of Agriculture and Bayer CropSciences.

Approaches

A network of approximately 5000 insect pest monitoring units were set up annually across canola and grain fields of Prairie Provinces (Alberta (AB), Saskatchewan (SK) and Manitoba (MB) from 2007 to 2009). These units included various types of traps (for example, pheromone or sticky traps), specific to the 7 key pest species targeted in the study. Insect monitoring teams were established in respective provinces to coordinate the set-up of monitoring sites, training, data collection and tool delivery. Insect monitoring protocols were compiled to ensure that best monitoring practices were implemented to run the program. Near real-time weather information was obtained from Environment Canada on a weekly basis, and degree-days for the target pests were accumulated daily, and incorporated as part of the updates. Wind trajectories were analysed to assist in predicting migration, and threat of, diamondback moth from United States of America and Mexico to Canada. Moreover, potential new invasive species and their natural enemies were monitored and the risks/benefits were quantified.

The information collected through all the sites was complied, summarized and delivered weekly to industry in the form of electronic pest and crop updates. Consisting of actual incidence along with forecasts and risk warnings for specific target pest, these updates were posted on the websites of collaborating organizations according to the crop(s) of their interest. Risk warnings were provided for each target pests in map format (prairie-wide, provincial and regional) accompanied with interpretive text and respective economic thresholds to help farmers, extension personnel, pesticide applicators and pesticide manufacturers make or recommend informed management decisions.

A survey was conducted to assess grower uptake of the tools delivered through this project and numerous technology transfer activities were held to communicate project outcomes to stakeholders.

Results

The seven pest species monitored annually throughout the growing season for the targeted crops at sites across the study region included (with associated number of survey stops/sampling for each species per year):

  • Bertha armyworm: approximately 450 canola fields across Alberta, Saskatchewan and Manitoba;
  • Diamondback moth: approximately 75 sentinel sites across canola fields in Alberta, Saskatchewan and Manitoba;
  • Cabbage Seedpod Weevil: approximately 550 canola fields across Alberta, Saskatchewan and Manitoba;
  • Wheat midge: approximately 600 wheat fields across Alberta and Saskatchewan;
  • Wheat stem sawfly: approximately 120 wheat fields across Alberta;
  • Grasshoppers: approximately 3,500 fields (after harvest) across Alberta, Saskatchewan and Manitoba;
  • Pea leaf weevil: approximately 75 fields of field peas and faba beans in Alberta.

Among others investigated for incidence, distribution and potential threat to prairie crops were cutworm and the invasive species cereal leaf beetle and swede midge.

Data resulting from monitoring were used to create interpretive maps accurately summarizing the near real time distribution and density of each target pest population. Risk warning maps were produced based on the annual insect population data combined with insect population trend data and spatial analyses incorporating weather data into the insect population dynamics models. Impact of natural enemies was also factored into risk-based recommendations whenever possible. For example, the larval cocoons of wheat midge, Sitodiplosis mosellana, were dissected to quantify the level of parasitism by Macroglenes penetrans.

Correspondingly, two risk warning maps were produced: one indicating the total density and distribution of wheat midge cocoons and the other indicating only viable wheat midge showing regions where the natural enemy has reduced the pest population to levels below the economic threshold.

Updated incidence and risk warnings maps, along with economic thresholds and risk-based control recommendations for each target pest were released weekly and made available to stakeholders from May to end of August through the websites of Canola Council of Canada, Western Grains Research Foundation, Canadian Wheat Board, and provincial governments. Summaries of regional monitoring and project results were continuously communicated to stakeholders through the Agriculture and Agri-Food Canada’s Technical Bulletin, various publications, media, and a number of presentations at grower meetings.

A survey conducted by the Canola Council of Canada in 2008 indicted that, of the 130 responding farmers, about 90% used pest forecasts and/or maps, 50% agreed that forecasts reduced overall environmental risk and 90% agreed that forecasts increased awareness of pest status. Of all forecasts/risk warnings produced by the project, the ones used the most were the grasshopper (85%), diamondback moth (77%) and bertha armyworm (76%) tools.

While the majority of prairie growers make use of these improved, knowledge-based decision support tools, it is anticipated that improved spray decisions and elimination of unnecessary pesticide applications has led to reduced input costs for growers and better protection of beneficial species such as natural enemies in the fields.

The Insect Monitoring Program, coordinated through specialist teams at each participating Prairie Province continues this work and the delivery of this service for the stated pests and crops. Some examples of updates for the 2012 season can be found at the Ministry of Agriculture for Saskatchewan and the Ministry of Agriculture and Rural Development for Alberta.

For more details on this project, please contact Dr. Owen Olfert: owen.olfert@agr.gc.ca.

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