2008 Pea Leaf Weevil Forecast

The pea leaf weevil (Sitona lineatus L.) increased in both severity of damage and range in the past year. The 2007 survey was based on damage ratings in 65 fields (17 municipalities) carried out in late May. For information about the pea leaf weevil life cycle.
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The survey is done based on leaf notch counts on 50 plants per survey field. The damage rating for a particular field is the average number of notches per plant. The pea leaf weevil has continued to expand its range beyond southern Alberta to include the southern portion of central Alberta. The survey was expanded north to Mountainview, Kneehill, Starland and the Special Areas. For the first year of the survey the true population level in the worst areas was somewhat masked by control efforts as producers are now using seed treatment and foliar applications to reduce pea leaf weevil damage. The pea leaf weevil has quickly moved outside its establishment area and is spreading into other parts of Alberta. This insect was also found this year in Saskatchewan for the first time. Its presence has been confirmed as far east as Maple Creek, SK. In order to track the spread of this insect further expansion of the survey will be necessary in 2008.

Although this is not a strict forecast, experience from the last couple of years has shown us that areas with greater than 9 notches per plant (dark tan on the map) have had high levels of damage in the next year. If this trend follows through into 2008 then we can expect high levels of pea leaf weevil damage throughout most of the area south of highway #1. Producers in areas with greater than 9 notches per plant should include control options in their pea crop budget for next year. The control options at this point include Matador as a foliar application and Cruiser as a seed treatment.

2008 forecast based on 2007 survey data

Life cycle information