FAQ

Thanks for your question about biting flies. Actually it’s very difficult to control biting and/or nuisance flies around the yard. Usually they like to breed in or around standing water because the larvae (immature flies) require moisture to survive. I wouldn’t normally think of Kanab being a particularly wet area in Utah. The adults move from marshy areas and can become a problem around households. Most females flies require blood to lay fertile eggs and they usually prefer to feed on birds and small mammals. But sometimes they have no choice but to move to larger mammals (us!).

Here are a few tips for reducing biting fly problems:

1.       Try to reduce or eliminate standing water around the yard (e.g., wheelbarrows, tires, watering cans, bird baths, kiddie pools, drainage ditches, etc.) to discourage females from laying eggs.

2.       Install proper screening for windows and patios to prevent no-see-ums from entering residences and outdoor areas. Most biting midges can pass through 16-mesh insect wire screen and netting, so a smaller mesh size is required.

3.       The small mesh size does limit air flow through the screens, and an alternative is to treat screens with a long-lasting insecticide (e.g., permethrin) that will be fatal to the no-see-ums that land on the screen.

4.       No-see-ums are very small and weak fliers; ceiling and window fans can be used at high speeds to keep no-see-ums out of small areas.

5.       If it is necessary to go outdoors into areas where biting flies are prevalent, wear protective clothing. Long sleeved shirts, long pants will protect arms, legs, and head from bites. If necessary, apply a repellent labeled for biting fly protection. Reapply as needed and as recommended on the label. Most repellents do not work as well for biting flies as they do for mosquitoes; therefore they have to be reapplied more often.

6.       Many biting flies are active at certain times. Avoid outdoor activity during these peak biting times. Horse flies, deer flies, black flies, and stable flies are usually most active during the day. Sand flies usually are most active around sunrise and sunset. Most of the biting flies are also most active at certain times of the year. Deer flies and black flies are most prevalent in early to late spring. Stable flies are most abundant in late August through October or November. Sand flies are most abundant during summer months, but may bite at any time during the year.

7.       Biting flies usually rest on vegetation or the sides of houses before entering or before biting people. Numbers of biting flies around houses can be reduced by applying outdoor barrier treatments to places flies would contact before biting or entering the house. Be sure to apply all products according to label directions and to locations listed on the label.

Biting flies are usually an area-wide control effort. Meaning, even if you try all the things listed above, flies can travel long distances and still be a problem. I am sorry I don’t have a more definite control recommendation for you. I hope the flies aren’t as bad this year for you. Best of luck,