- Last Updated on Wednesday, 04 June 2014 00:26
- Published on Wednesday, 04 June 2014 00:26
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No one reading this article, or any of their relatives before or after, that lives in America near any sort of vegetation, has ever been immune to and had always been a victim of pesky, biting deerflies. We’ve all experienced them, and this year will be no better. Already, I’ve received several calls on this bloodthirsty insect.
Chrysops spp, or deer fly, are slightly larger than house flies, and mostly yellow or black with darker stripes on the abdomen and dark markings or patterns on the wings. They have brilliant green or golden eyes with zigzag stripes. Deer flies are vicious, painful biters. They are very predatory, and wait on vegetation to attack and feed on the blood of cattle, horses, mules, hogs, dogs, deer, other warm blooded animals, and humans.
Biting deer flies frequently attack humans in yards, near streams, and at the edges of moist, wooded areas.
Deer flies are almost nearly impossible to control. The eggs are deposited in masses usually on vegetation or near water or wetlands. After eggs hatch in 5 to 12 days, small larvae drop down and burrow into moist, wet soil found in marshes, stream banks, and bottoms of lakes and ponds. They may drop into rapidly flowing streams or burrow into dry soil. Larvae feed on organic debris, other insects, tiny crustaceans, snails, earthworms, and aquatic or semiaquatic organisms. Other than utilizing aerial insectivores such as purple martins and barn swallows, no satisfactory methods have been developed for control of deer flies. Even purple martins and barn swallows offer limited help as the deer fly remains seated until it spots a moving victim. It is impractical in most regions to eliminate the breeding areas. Draining marshes and wet meadows where flies develop may appear to be of the greatest value, but should be done in such a way as to preserve the desirable wildlife of such areas, if possible. Fortunately, the season for deer flies is rather short, usually four to five weeks in June or July. The greatest deer fly activity occurs on warm, sunny days when there is little or no wind. Deer flies seem to be attracted to the highest point of moving objects and dark shapes; this is why they attack humans especially around the face and neck areas.
However, there are some things that can be done. Recent research has found that deer flies are highly attracted to the bright blue color, the same blue color found on disposable plastic cups and plates. Very recently, it was found that a six inch diameter blue plastic disposable plate covered in Tanglefoot, a very sticky clear insect trap paste that is purchased in a tube, would trap the deer flies to the plate when velcroed to the back of the cap of outdoorsmen, without the victim getting one bite.
Knowing they are predatory and wait for moving victims, researchers have concluded that large, moving objects that are 3 – 6 feet off the ground level will attract deer flies. To make a workable deer fly trap, large black balloons tied to the lower branches of trees that move around in the wind with blue, sticky plates taped on top did in fact attract and trap hundreds of deer flies.
I hope this information helps those who live in areas that deer flies find attractive. If you have any questions or concerns, please call or email me at the county office.
—Mike Broaddus, Ag and Natural Resources Agent