Pea leaf weevil major bug to watch for in Alberta this year

Alberta insect management specialist Scott Meers started his Jan. 18 presentation with the good news about insect problems in 2016.

Wheat stem sawflies, grasshoppers and bertha armyworms mostly kept their noses — and other insect parts — out of farmers’ business last year.

The same will not likely be said in 2017 about pea leaf weevil, cabbage seedpod weevil and wheat midge.

Meers gave an overview and some 2017 predictions on insect pressure during the Agronomy Update in Lethbridge.

“The pea leaf weevil has gotten crazy,” said Meers, calling its range and damage “at times a little bit breathtaking.”

Seed treatments offer the main protection against these pests but they don’t kill all the weevils and foliage treatments don’t usually translate into yield response.

Peas and faba beans in parts of Alberta were hit hard by pea leaf weevils this year.

ADVERTISMENT

Looking ahead to planting, Meers advised farmers to wait until the soil warms.

“As soon as that seed goes into the ground, the clock starts ticking on efficacy of insecticide seed treatment. You lose power on it by the time it’s needed.”

Its often possible to seed peas in April, said Meers, but managing the seeding date will be important for pea leaf weevil control this year.

The weevil has steadily expanded its range in Alberta. Areas around Red Deer and Lethbridge appear to be hot spots for 2017 based on 2016 surveys.

Forecasts also indicate increased risk for wheat midge damage in 2017, said Meers. Late seeded fields generally carry a higher risk but there are effective controls.

Crop damage from midge is “not a laughing matter. We’ve seen 50 percent yield loss in parts of Alberta when populations get out of control.”

ADVERTISMENT

Meers said there are residual wheat midge populations around Falher, a building population east of Edmonton and a few irrigated wheat fields in southern Alberta with signs of potential high numbers in 2017.

Planting midge tolerant wheat in those areas should be considered, he said, and if that isn’t an option, farmers should plant early to get ahead of potential wheat midge damage.

Cabbage seedpod weevil continues to extend its range and the 2016 survey showed it has spread along the Highway 2 corridor almost to Edmonton. It has also spread to an area south of Lloydminster.

Meers said canola at first flower is at highest risk.

“It’s easy to manage. You go sweep, make your decision, spray if you have to.”

Flea beetle risk will depend on spring weather but Meers said early seeded canola is more likely to require spraying for this pest.

ADVERTISMENT

For more information, visit 
http://bit.ly/1ParTzZ.