Gavloski said research is needed to determine the effectiveness and most ideal time for multi-insect spraying. Seed weevils and banded sunflower moths usually move into sunflower fields as they are beginning to bloom, which in some years may be too late to spray for sunflower beetles. But in other years, it may be possible to delay spraying until then to get some control for all three insects. While not always effective, targeting more than one pest with a single insecticide may help some farmers reduce insecticide costs with minimal reduction in control, said Gavloski. Armyworms True armyworms, which will feed on cereal crops as well as timothy hay, enjoyed a resurgence in eastern Manitoba last year.
Armyworms are most likely to flourish where there is a dense canopy.
If you get some lodged grain, that's where you're more likely to find them in the highest numbers. Patch spraying is an option when armyworms are concentrated in areas of dense or lodged grain. Gavloski said the technique seemed to be successful in Manitoba last year. As far as I know, they didn't have to go back and spray those fields a second time. However, he said patch spraying works only if armyworms are highly concentrated in specific areas of the field, which is not always the case.