Much of southern and central Alberta and parts of western Saskatchewan still have high levels of lygus bug feeding. Lygus bug numbers are up to 10 times economic control thresholds in fields from Crossfield to Penhold, Alberta.
Economic thresholds at pod ripening are 8-20 adults or late instar bugs per 10 sweeps when canola prices are $10 to $12 per bushel. (See the first table below for more details.)
At these numbers, spraying is warranted to save yield but remember the pre-harvest intervals. Products with the shortest pre-harvest intervals still require 7 days between spraying and cutting, so if the field is within a week of swathing, then spraying is no longer an option. (See the second table below for a table of pre-harvest (pre-cutting) intervals.) In fields that close to cutting, many pods are hardening and lygus will not be able to penetrate and cause damage anyway.
In severe cases, swathing a little earlier than recommended — perhaps at 30% to 40% seed colour change instead of the ideal 50% to 60% — may be the best solution.