How to control annoying stable flies

They look like house flies. But these buggers bite. The stable fly has a well-earned reputation as a persistent and severe biter.

It’s about seven millimeters long and can be told from the common house fly by a checkerboard pattern on the top of the abdomen and a stiletto-like proboscis that protrudes forward of the head.

Stable flies (also called dog flies and biting house flies) are bloodsucking insects that cause considerable discomfort, irritation and injury to livestock, pets and people. Stable flies often attack dogs around the ears and nose resulting in raw, bleeding wounds.

Anyone who was raised on a farm knows the misery they can inflict on cattle and horses. In large enough numbers, they can induce extreme stress causing weight loss. In rare cases, death can occur.

Unlike most blood-feeding species of fly, both the males and the females bite. The female needs blood to increase the viability of its eggs. She can lay up to 3,000 in her short life span and will feed multiple times during the day. These flies breed in animal and poultry manure, decaying plant material, poorly managed compost and piles of grass clippings.

Sanitation is the most effective and important step in controlling stable flies. Their maggots are semi-aquatic and require moisture to develop. Controlling moisture is essential. Keep all animal enclosures clean, daily if possible. Collect any droppings from your dog or manure from stabled horses or cattle. Get rid of any soiled, wet straw or bedding, spilled animal feed or silage. Dispose of piles of old, wet lawn clippings, leaves or other debris.

If you can’t dispose of the manure, place it in a fly-proof container or cover it with a tarp or heavy plastic sheeting. Covering it will heat up the organic material killing the maggots. If you can bury it, make certain that it’s at least five centimeters (two inches) below soil level.

Other than eliminating the breeding sites, your only other option would be insecticides. The quick knockdown types such as fogs are highly effective in the short term. They will kill any adults present when the area is fogged. But they have limited residual activity. Long-term residual insecticides will kill more slowly. They will continue to kill for days and sometimes months.

Stable flies like to land on vertical surfaces when at rest. Spraying fences, the sides of buildings, inside and outsides of stalls increase the potential for contact. Look around. Light surfaces are preferred over dark ones. Any favored site will be dotted with small dark spots of the flies’ fecal material.

Other control methods are less certain. Fly baits, bug zappers and other traps have some limited use for general fly control but tend to be less effective with stable flies. Remember, even if you don’t have any livestock or pets, stable flies can still show up where you live. The little suckers have been observed traveling up to six miles to get a meal.

This story was originally published April 30, 2017 at 12:00 AM with the headline "How to control annoying stable flies."