Surface Sprays for Killing Flies

The use of a surface spray is often needed in outdoor fly control. Not all flies can be controlled by spraying exterior surfaces. Cluster flies, house flies and other flying pests can sometimes be seen resting on flat surfaces. In this case, a long residual insecticide can be very helpful in their control, reducing the number of flies that actually enter the structure. When biting flies are present, surface sprays rarely work because the flies are usually looking for a meal, not a resting place.

Surfaces such as the outside walls of a home and inside walls of barns, warehouses and other structures can be sprayed with products that will kill resting flies while controlling other household pests as well. Professional pesticides with a long residual include Cynoff WP, Demon WP and Talstar One. Wettable powders can leave a visible residue on dark surfaces. If this residue is undesirable, use Talstar One, Cynoff EC or Demon EC/ Demon Max. Use Permethrin Pro in sensitive areas such as horse barns, stalls, dog kennels or chicken coops.

Simple liquid concentrates such as Permethrin Pro, Cynoff EC and Demon EC will not leave a visible residue but have a much shorter life outdoors than wettable powders or Talstar One. In outdoor areas where soil is constantly moist (beneath older buildings, crawl spaces under homes and schools, etc.) Talstar One can give 1 to 3 months residual. As a general rule, liquid concentrates (insecticides with "EC" in their brand name) will last about 30 days indoors, 10 to 30 days outdoors. Wettable powders (WP) will last 90 days or longer indoors, 30 to 90 days outdoors. Moisture, heat, cold, type of surface and pests targeted are variables that influence the longevity or residual of an insecticide used on exterior surfaces. Talstar One, Demand CS and Suspend SC are liquid concentrates that give longer residuals than an insecticide designated as an "EC" but they do not usually last as long (on same surface types) as a wettable powder. For more information go to insecticide concentrate, wettable powders web pages.

The use of a surface spray is not always the only means of controlling a fly infestation, but it can be a tremendous help in certain circumstances. An integrated approach (IPM) is always best. Can the fly's food and breeding source be eliminated or at least limited? Are you sure of the type of fly you are fighting? Once you determine the species of the fly, simple sanitation procedures can have a huge influence on your infestation. If source of flies is not on your property or otherwise out of your control, be patient with your pest control tools. Surface sprays, ultraviolet fly traps, fly zappers and professional fly bait will all do a good job when used correctly or in combination with each other.