The adult sunflower midge is about two millimeters (3/32 inch) in length with a four millimeters (3/16) wingspan. The body is tan‑colored and the wings are transparent and without markings except for veins. Mature larvae are about three millimeters (1/8 inch) long, with tapered bodies, no head capsule, and cream to yellowish orange in color. Midges overwinter as cocooned larvae in the soil and pupate during June. Adults emerge from the pupae in early to mid‑July and live for about three days. Females prefer to lay eggs on heads one to two inches in diameter. Initially, larvae feed on the margins of the head between the bracts. Later, larvae migrate to the center of the head and feed near the base of the developing seeds. Mature midge larvae crawl to the surface of the head and drop to the ground to overwinter.
Midge larvae feed by dissolving plant material with salivary secretions, then eating the dissolved material. Most larval damage is caused when many larvae feed in the center of the developing bud. Twisting or gnarling often results and heavy seed loss can occur. Substantial economic loss can occur during large population outbreaks.
Categories: Sunflower, Insects, Sunflower midge
Date: 04/16/2004