June 25, 2025

QUIZ – Insects this week

Four questions on insects eating canola this week. Two are common, and at high numbers in some areas. Two are not common, but interesting.

1. Cabbage seedpod weevils seem to be at higher-than-usual numbers within their geographic range, and an agronomist at Elbow, Saskatchewan says numbers are “heavier than ever.” What is the ideal spray timing?

Cabbage seedpod weevil on a canola flower
Cabbage seedpod weevil on a canola flower; Credit Shelley Barkley
2. The following describes a pest also seen at higher-than-usual numbers this year...in some spots: The larvae (caterpillars) are a pale yellowish-green to green colour and are covered with fine, scattered, erect hairs. The posterior end of the caterpillar is forked. At maturity the larvae are cigar-shaped and about 12 millimetres (0.5 inch) long. What is it?
3. Red turnip beetle has been found in some Alberta canola fields. They are rarely at economic numbers. What is the economic threshold for red turnip beetle?

Red turnip beetle on a canola plant
Red turnip beetle; Credit Shelley Barkley
4. Every few years, we hear of isolated but nasty cases of "little red bugs". Last time we wrote about them in Canola Watch was 2018. Jim Tansey, insect management specialist for Saskatchewwan, heard this year of 40 acres of canola “affected significantly” in east central Saskatchewan. These insect hoards work deep in the canopy doing what?

 

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