Do Your Own Pest Control - Log In or Register
Do-It-Yourself Pest Control Do-It-Yourself Pest Control My Account | My Cart | Checkout

How to Get Rid of Cluster Flies

Cluster Flies

Filth Flies

Small Flies

Nuisance and Biting Flies

Cluster Fly Control

 

Prevent Cluster Flies

Prevention is the best measure to keep away Cluster Flies. Fall months are the times to use a good residual sprays before they enter the building and over-winter. Spray the outside walls of the building where cluster flies are likely to land and rest before entering the building.

Spray recommended residual insecticides, such as Bifen IT, D-Fense SC or Cyper WP. Apply these insecticides outdoors to window frames, door frames, soffits and eaves as well as any other areas that are vulnerable to entry. Spray beneath the eaves and around the windows and other areas where flies are likely to seek entry.

Application of to the surrounding soil with D-Fense SC or Bifen IT may also help minimize Cluster Fly populations and later entry.

Active Cluster Fly Infestations

Cluster fly problems 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.

If this is not successful, an aerosol contact pyrethrin aerosol can be used as a space spray to get some immediate relief. Recommended pyrethrin aerosols are CB-80, PT 565, or V-One pyrethrum contact aerosols.

 

 

Recommended Cluster Fly Control Products

Insecticide Concentrates

D-Fense SC Insecticide

  • D-Fense SC is a long term residual and does not break down easily outside on wall surfaces.
  • It is odorless and does not leave a stain.
  • D-Fense SC can be used on the ground as a preventive measure.

Cyper WP

  • Cyper WP with Cypermethrin is an orderless product just like the D-Fense, but will leave a visible residue seen against dark surfaces.
  • Cyper WP is not labeled for ground, broadcast spraying.
 

Insecticide Dusts

You can also use a dust D-Fense Dust. Dust this into all cracks and crevices. The dust will flow into the void areas. Pay attention to the west and south walls and caulk any openings.

 

Insecticide Aerosols

Use aerosols with pyrethrins such as: CB-80, PT 565, or V-One. These are pyrethrum contact aerosols that can be used as space sprays to kill on contact. Spray lightly and repeat spray as needed.

 

 

Identifying the Cluster Fly

The cluster fly averages between 1/4 to 3/8 inch long. They are dark gray, never metallic blue or green. When crushed, they give off an odor like buckwheat honey. Cluster flies closely resemble house flies, but they are usually larger and have a yellowish sheen on the thorax.

Biology and Habits of Cluster Flies

The cluster fly is a parasite of earthworms and breeds outdoors in lawns and fields during the spring and summer. You can find cluster flies almost everywhere in the United States and Canada, except for the Southern states bordering the Gulf of Mexico.

Female Cluster Flies lay their eggs in cracks in the soil, which hatch in three days. The larvae use earthworms as a food source. The larvae feed for about 22 days. After that, they go into the pupae stage, which lasts 11-14 days before emerging as adults. Adult flies feed on flowers. There are about four generations hatched per summer.

When fall approaches, the cluster flies begin to enter structures in large numbers. Problems with cluster flies begin in late August as they move to winter quarters to over-winter. The cluster fly is seeking warm sites with protective cracks for shelter, crawling back as far as they can get. It is important to consider treatment before this happens.

Cluster flies have been known to squeeze around the edges of windows that are weather-proofed. As the number of cluster flies attracted to the building increases, large clusters of flies huddle inside wall voids, attics, and false ceilings. Most infestations occur in the upper regions of buildings, such as the attics of homes. In multi-story buildings, the cluster flies can be found in the upper two or three floors, and almost always of the south and west sides of the buildings.

If you have unseasonably warm weather in the late fall or winter, the cluster fly may emerge thinking it is spring, going for the warmer air outside. Cluster flies fly very slowly when they just wake up. They are strongly attracted to light, so they are usually found around windows. At night, they are attracted to lamps.

Cluster Fly Inspection

 

Check around windows for live or dead flies. If you can find the voids in which they are over-wintering, you can treat the voids with a dust or aerosol, but that is not an easy task. In most cases, the voids can't be located.

 

To locate the voids, start with an inspection of cracks and crevices on the southern and western exterior walls. Usually the only accessible voids are the attics, crawls paces and false ceilings.

D-Fense SC Insecticide

d fense sc

cb 80 pyrethrin


Cyper WP

cyper wp

cyper wp


D-Fense Dust

d-fense dust

d-fense dust


CB 80 Contact Aerosol

cb 80 extra pyrethrin aerosol

cb 80 pyrethrin