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Photo courtesy of:
Oklahoma State University
Entomology and Plant Pathology

Both face and cluster flies overwinter in structures and are a nuisance.

They will overwinter inside structures (in walls, attics, under siding, within voids of overhangs, in basements, and in other sheltered locations. They mate after emerging in the spring.

Neither cluster flies nor face flies multiply within structures.

 Although the preferred food of choice for the Face Fly is the mucus and the watery secretions around the eyes, nose and mouth of cattle and horses in the summer months. Face flies can transmit pinkeye to livestock.They will also feed on blood, flower nectar, and dung fluid.

Inspecting for Face Flies

Female face flies tend to cluster in large numbers around the face of cattle and horses.

Adults can also be found around bushes, tall grass, weeds, and fence posts.

In the winter, adults seek shelter in such places as attics, wall voids and basements.

Face flies can be found on cattle farms since they develop in fresh manure.

Any structures close to farms, barns, ranches, stockyards can be infested.

FACE FLIES OVERWINTER:

Face flies and cluster flies may hibernate in the walls of homes or other buildings during the fall and winter months. When the temperatures lower, the adult Face flies are attracted to the warmth of the walls.

Particulary attractive are the south and east sides of structures because of the late summer sun.

During spring or on a warm day, these flies become active and come inside your homes.

They are attracted to light and may be found near windows or light bulbs.

Face Fly Control and Elimination

Management of Face Flies

As with all fly control , the best measure of pest control is removal of their breeding sources that promote larval growth. The face flies breed in fresh cattle manure that has not been disturbed, so removing these sites may not be possible. However by increasing the cattle movement in a given area by restricting their pasture area , these manure areas with be disturbed and reduce the development of the larval forms.

Face fly problems in stuctures can be partially prevented, but after the fall little can be done.

All of those currently found within the home had infiltrated walls months ago.

A "mini-vac" is the best control of the individual flies that are currently present.

Begin searching for resting sites on the southern and western sides of the building because in fall and winter these walls receive the most sun and therefore are usually the warmest parts of the building. The flies are attracted to these warm areas when searching for protective wintertime harborage.

If this is not successful an aerosol like CB-80 pryethrum contact aerosol can be used. Spray lightly and repeat spray as needed.

Electronic fly traps for residential and commercial use can be found at FLY CONTROL.

Late August and early September are the times to use a good residual spray like Suspend or Demon WP,spraying the outside walls of the building where face flies are likely to land and rest before entering the building.

These residual insecticides are applied outdoors to window frames, door frames, soffits and eaves as well as any other areas that are vulnerable to entry.

Recommended also would be a dust like Delta Dust, dusted into cracks that have not been sealed, allowing the dust to flow back into the void areas.Thoroughly caulking all exterior cracks on the sun-exposed sides (south and west) is very important.