Where Are Black Flies the Worst?

Black flies can be a nuisance and a real pain, especially when you’re outdoors, but the good news is that you can protect yourself from the bites by knowing where they tend to occur. Black flies are most prevalent around wooded areas with leaf litter. In addition to bothering humans, black flies can also annoy animals, such as cows and horses. Many of these insects can even be harmful to livestock, and their bites can reduce the weight gain and milk production of cows.

Black flies tend to be most active during late spring and early summer. Their bites are typically very itchy and painful. The bites are similar to those from small bee stings. The sting is painful because the fly cuts the skin in order to suck blood. Additionally, the itch is caused by the anticoagulant in the saliva of the flies. If you find yourself with a black fly bite, it is recommended to use antihistamine to soothe the itch.

Black flies can pose a serious threat to livestock in Canada. Attacks have reduced grazing and caused cattle to lose weight. In addition, black flies carry a toxin that can cause anaphylactic shock in animals. In some cases, black flies can even transmit parasites to livestock.