What is a blackfly?
The blackfly represents a blue-grey to black mosquito up to six millimeters in size, whose female animals suck blood from warm-blooded animals and humans. They do not bite the host in the narrower sense, but create a wound with their mouth parts, from which they then suck. The blackfly feeds on the nectar of many plants, only the females need blood for egg development. They track down their possible host by the smell of carbon dioxide and optically.
Which diseases are transmitted by the blackfly?
The bite of the blackfly is very painful and often leads to local bruising and severe swelling. The secretion of the hormone histamine often leads to pseudoallergic reactions which are dangerous. Many black flies transfer poisonous substances into the wounds of stung people, causing them to become purulent.
This initially local infection often develops into an inflammation of the lymph vessels, which can lead to blood poisoning. Especially African subgroups of the blackfly transmit threadworms, which is called “onchocerciasis”. Most infected persons complain of nodules and inflammation of the skin. About ten percent of those infected go blind due to the colonization of the worm, which in this context is called “river blindness“. In Europe, the black flies also transmit dangerous diseases, such as Lyme disease, which can lead to pain, inflammation and nervous breakdown.
What does the blackfly’s bite look like?
Since black flies are rather small mosquitoes and fly silently to humans, their bite is usually not noticed. They do not bite humans directly to suck their blood, but first bite a wound. Blood collects in it, which is constantly flowing in the saliva of the blackfly due to a coagulation inhibitor.
The mosquito then drinks the blood from these “pools”. The bitten person then often notices a small bleeding spot and/or a bloodshot spot on the skin. In addition, the hormone histamine in the saliva of the blackfly can cause a small nodule to form under the skin.
In the course of the disease, a small purulent blister often forms at the site of the bite and a redness of one to two centimeters around the bite. The itching and the swelling of the mosquito bite is caused by the hormone histamine in the mosquito saliva, which is then further secreted by the own body. It is actually a defensive reaction of the body. However, too much scratching can carry infectious agents into the wound, which can then lead to a severe inflammation.
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