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Black Fly: Treating And Preventing Painful Bites

Black fly

Imagine this: You’re spending time outdoors in spring or summer when a small, grayish-black flying insect lands on your skin and bites you in order to feed on your blood. You smack at it, but it’s too quick—it zips away, leaving you with a red, itchy, painful welt. Not too hard to picture, is it? Most of us far more familiar with mosquitoes than we want to be, but how much do you know about the black fly?

While mosquitoes are a serious annoyance for those of us trying to enjoy some time outdoors through the warmer months of the year, mosquito bites pale in comparison to the nasty bite of the black fly. Unlike mosquitoes, which typically bite people most in the mornings and evenings, black flies bite all day long.

While not as prevalent in the southern states as they are in other regions of the U.S., black flies have been known to bother both people and animals across the country. This should come as no surprise, considering that North America is home to more than 20,000 species of flies, and over 250 different species of black flies.

Unfortunately, black fly bites are painful, and they can be more than just a nuisance. In parts of Africa and the Middle East, as well as Central and South America, black flies have been known to transmit a disease called river blindness, which can cause permanent blindness in humans if not caught early.

Certain other species of animal can also be quite adversely affected by black flies. Multiple black fly bites have been known to endanger certain bird populations, such as purple martins, by killing their nesting baby birds. Also commonly known as “buffalo gnats” or “turkey gnats”, black flies bother many types of animals. Black fly bites have even killed animals as large as livestock via toxemia—blood poisoning that can result from the bites—and suffocation, when the flies block airways by swarming into the animals’ noses and throats. Their bites can also transmit several different diseases and disease agents to animals.

In some areas, larger fly species can bite humans and animals. Bites from deer flies and horse flies can produce a swollen, painful area for victims and can be way diseases are transmitted to certain types of livestock.

How dangerous are black fly bites for humans? What steps can you take to keep this pest away from your home, yard and the people and animals you care about? Read on to find out more about the black fly, including tips for treating and preventing its painful bite.

Black Fly: Habitat And Life Cycle

Springtime, with its warm yet gentle temperatures and moderate to heavy rainfall in much of the U.S., provides the perfect conditions for adult black flies to thrive. Many species of black fly die out once summer temperatures soar, but warmer parts of the country seem to be home to certain species of this pest that continue to bother both people and animals even through the hottest parts of summer.

Black flies lay eggs on vegetation, rocks, logs and other solid surfaces that are located either in or around water, such as gently flowing rivers and streams. They can also lay eggs in muddy, less flowing wet sites. When black fly eggs hatch into larvae, some attach themselves to rocks or plants underwater, while others stay on drier ground and feed on wet, rotting organic matter. Once the larvae progress to the pupal stage and then hatch into adult black flies, they are ready to feed, mate and continue the cycle. How long do flies live? The black fly life cycle lasts about three weeks.

Black flies are fast and hardy insects that can fly far, sometimes traveling up to 10 miles from their breeding sites. It is only the female black fly that bites humans and other animals to feed on their blood. Black flies feed on livestock, poultry, birds and other animals for a blood meal. It is important to note that black flies are not the same as house flies, though they look relatively similar (although some black fly species are quite small, measuring just five millimeters in length). One major difference between black flies and house flies is that house flies don’t bite humans (or animals), although both types of fly can be vectors for disease.

Black fly bites treatment

Black Fly Bites: Treatment Methods

When a black fly bites you, it feeds very quickly. Its mouthparts are actually specially designed with serrated mandibles that puncture skin quickly and rip it open, enabling the black fly to get a full meal before it is swatted away. No wonder this insect’s bite is so painful!

The most uncomfortable part of a black fly bite is actually the result of the anticoagulant the insect pumps into the skin when it begins to feed. The anticoagulant makes the blood flow more freely and quickly, and it causes itching, pain and swelling at the site of the bite.

When you suffer a black fly bite, it’s important to clean the site of the bite with soap and water as soon as possible. Scratching an itchy black fly bite is understandable, but doing so can enlarge the wound site and wind up creating a secondary infection. Keeping it clean and avoiding scratching will help prevent infection. You can also apply over-the-counter anti-itch (cortisone) cream to the bite to reduce the urge to scratch.

Some people suffer from black fly fever—a collection of symptoms beyond the pain, itching and swelling at the bite site. Read on to learn more.

Black fly fever

Black Fly Fever: How to Protect Yourself

“Black fly fever” sounds serious, and it certainly can be, in individuals who are highly allergic to black fly bites—but in reality, black fly fever simply refers to the collection of symptoms that black fly bites can cause. This can include the itching, a painful welt at the site of the bite, along with nausea, fever, headache, aching joints and swollen glands. Not everyone who is bitten by a black fly will experience all of these symptoms; many will experience nothing more serious than temporary discomfort at the bite site.

People who develop black fly fever including headaches and nausea are generally able to treat their symptoms at home with common, over-the-counter remedies. It is rare but possible to develop a very severe allergic reaction to black fly bites, so if you are bitten and have severe symptoms, do check with your doctor about treatment.

Whether your symptoms are mild or severe, black fly bites are no fun. To protect yourself against them when doing yardwork or other activities outdoors, be sure to wear protective clothing. If you plan to be outdoors for a long period when black flies are rampant, you might consider wearing long sleeves and pant legs (if it’s excessively hot out, be sure to wear light colors and drink lots of water). Mesh coverings can also protect your scalp, face and neck from these creatures.

Black fly repellent

Black Fly Repellent: Does It Work?

Insect repellents containing DEET can be an effective barrier against black flies, as well as other biting or stinging pests. How does DEET work? It interferes with the insects’ ability to find you by covering up your scent. You may have to reapply the product somewhat frequently, however, to keep the flies at bay for long. Other options for repelling black flies include wearing clothing that has been treated with permethrin, a synthetic insecticide, and using repellents containing neem oil, a natural bug repellent derived from a certain type of tree in India.

While some people believe wearing permethrin-treated hats or clothes can help, however, others report that these products are ineffective. Furthermore, different black fly species may respond differently to various products, so finding one—or a combination of products—that works for you may take some trial and error.

Some people also like to use a less chemical, more natural repellent to keep black flies at bay, such as wearing lemon or eucalyptus essential oils or lighting citronella candles outside. The truth is, however, that these products are not very likely to be effective. Since black flies hunt by sight rather than by smell, they aren’t as deterred by pungent-smelling products as certain other insects are.

The best way to avoid black fly bites might be simply to stay indoors and use your air conditioner, and venture out only at nighttime when black flies have finished their feeding for the day. But what about those times when you want or need to spend time outside during daylight hours, when black flies are most active?

Get rid of black flies

ABC Can Help Get Rid Of Black Flies

Keeping black flies away from your home and property is a complicated process. There are certain measures homeowners can take that can be effective, especially if used in tandem with other methods. Burning citronella candles, torches or coils, for example, can help repel black flies and other biting flies from your outdoor spaces. Increasing airflow can also help; using a ceiling or box fan should create enough moving air to deter flies, though it is unlikely to keep them away entirely.

Since black flies are attracted to wet areas and they tend to hang out in vegetation, you can reduce their habitat by keeping your bushes pruned and your grass mowed short. It is also wise to drain any standing water in your yard (which helps keep away mosquitoes and other unwanted pests as well), and clear out areas where dead leaves accumulate, especially if they are damp.

Even if you take all of these steps, however, you still may have trouble combating black flies in your yard. Black flies are difficult to control in nature, especially in rural areas and areas that are environmentally sensitive; the fact that they breed near water or wetlands makes it tough to use stronger chemicals that might be more effective at keeping them away. If black flies or other stinging insects are making it difficult to enjoy your time outdoors, it’s time to call ABC Home & Commercial Services. Our pest control specialists are experienced in eradicating all kinds of unwelcome pests and critters from homes and yards, and we can use environmentally friendly products that are safe for your home and pets.

Holt Myers

Holt joined ABC in 2021 as the Electrical & Appliance Operations Manager before transitioning to Division Manager for Pest Control. Before ABC, Holt worked as a Project Manager and Superintendent in Construction. Holt also served in the US Marine Corps from 2003 to 2007. Holt is a member of NPMA’s PestVets, Stewards of the Wild and Texas Wildlife Association. Holt is an avid outdoorsman, who loves to travel and spend time with his wife and daughter.

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