Do Sunflowers Increase House Flies?

The dark disc in the center of a sunflower is made up of hundreds of tiny flowers.

A summer staple, the sunflower is a cheery addition to any garden. If you're growing sunflowers for seeds, you might be worried about house flies. These ubiquitous pests seem to get into everything; but, fortunately, sunflowers aren't on their menu. But there are some other types of flies whose maggots feed on sunflowers. These flies might end up in your house.

House Flies

House flies feed on a bunch of disgusting stuff. According to Penn State, they feed on fecal matter, pus from wounds, sputum and many other moist, rotting items like decaying flesh or food. If you are seeing an increase in housefly activity in or around your home, check for a decaying animal that might be in your attic or somewhere outside. Clean up any animal waste around your yard. Empty garbage cans and be sure all of your window and door screens fit tightly.

Sunflower Receptacle Maggot

Adult sunflower receptacle maggots are yellow, with green eyes and mottled brown wings. They are almost 1/2 inch in length. Their larvae are yellowish white and nearly the same size as adults. Sunflower receptacle maggots lay their eggs at the bract of a young flower head. Larvae feed on the bract and burrow out when they mature. They don't typically damage the sunflower and don't usually require control.

Sunflower Maggot

The sunflower maggot is creamy white and feeds on young flower stems. Adults are yellow flies and have clear wings mottled with light brown. An F-shaped pattern is clearly visible at each wingtip. Females lay eggs at the stem just beneath the flower, and maggots feed on the tissue within the stem. Much like the sunflower receptacle maggot, the sunflower maggot does little damage and shouldn't require control.

Sunflower Seed Maggot

Adult female sunflower seed maggots lay eggs directly into the center of sunflowers. The center of each sunflower comprises hundreds of tiny flowers that, if pollinated, will become seeds. Sunflower seed maggots feed on these flowers, also called disc flowers. Adults are light brown with brown and clear mottled wings. Although they damage flowers and prevent seeding, these maggots don't do much damage. They usually damage only a few seeds per flower, so control isn't necessary.

References

• IPM World; Sunflower Insect Pest Management in North America; Larry D. Charlet, et al.
• Penn State Entomology; House Flies; Steve Jacobs; August, 2007
• Manitoba Agriculture, Food and Rural Initiatives: Sunflower Maggots