The sunflower receptacle maggot adult is a small fly about 10 millimeters (5/16 inch) long, with a wingspan of about 18 millimeters (3/4 inch). The eyes are bright green and wings have a brown mottled pattern. Larvae are yellowish white in color and tapered from front to rear. Mature larvae are about eight millimeters (5/16) in length. Adults emerge in June to early July and lay eggs on bracts of developing sunflower heads. After about 30 days, the mature larvae drop to the soil to pupate in late August or early September. Overwintering pupae are found over six inches under the surface. Some larvae will pupate in the sunflower head. There is one generation per year in this region.
Mature larvae cut a small emergence hole on the underside of the receptacle. Significant yield losses have not been demonstrated with this insect.
Insecticide treatments are not considered necessary under most conditions.
Categories: Sunflower, Insects, Sunflower receptacle maggot
Date: 04/16/2004