When monitoring sunflower heads, look for the midge larvae in the flower head, scarred bracts, and twisted or gnarled flowers. The larvae may be found at the base of the bracts or feeding in the flower, at the base of the florets. A 10x magnifier helps in locating the tiny larvae. No threshold has been established for this pest in either oil type or confection sunflowers. However, later infestations can still be severe.
Some commercial hybrids are tolerant or resistant to the sunflower midge.
Consult your provincial agricultural representative for information on the most resistant varieties. Insecticides do not work well against this pest. They provide inconsistent and inadequate control of the adults and larvae. Because the larvae crawl into the bud soon after hatching, they are protected from foliar applications. Insecticides can control the sunflower midge only if they are applied to the foliage just before the adults emerge.