Originally submitted: July 8, 2021
Written collaboratively by Adam Varenhorst, Patrick Wagner, Philip Rozeboom and Aaron Hargens.
Quite a few sunflower receptacle maggot flies have been spotted in South Dakota sunflower fields. The adults don’t feed on sunflower, but the larvae of this insect are considered minor pests of South Dakota sunflower.
Right now, the flies are laying eggs on developing sunflower bracts. When the eggs hatch, the larvae will burrow into the head to feed on the receptacle.
Identification
The adult sunflower receptacle maggot fly is approximately 5/16 of an inch in length. They have clear wings with dark coloration on them. They have a light-yellow body and legs with green-yellow metallic colored eyes (Figure 1).
The larvae of the sunflower receptacle maggot fly are typically not observed, as they feed within the sunflower receptacle. They reach 5/16 of an inch in length and are a yellow-white color (Figure 2). They have a dark brown-black head capsule.
Scouting
These flies are active from late June to mid-August. The larvae will leave the head at maturity to pupate in the soil. There is one generation of this pest per year.
Monitor adult activity, and in mid-August begin scouting heads for exit holes from the larvae.
Management
Insecticide management is not recommended for this pest. Crop rotation typically reduces the pressure from sunflower receptacle maggots.
