What is Black Fly?
The black fly belongs to the family Simuliidae. The black soldier fly is also known as buffalo gnat or turkey gnat. There are about 1,800 small species of humpbacked flies placed in the order Diptera. The little black flies usually appear in black or dark grey in colour, with gauzy wings, stout antennae and legs. Further, they have short mouthparts, which are adapted for sucking blood. Only female black fruit fly can bite and sometimes huge black flies together may kill chickens, birds, and other domestic animals.
Some species of black fly may carry parasites, which are capable of causing onchocerciasis. Later, the onchocerciasis may lead to blindness or nodules beneath the skin. Usually, the larvae and pupae of the black flies are flowing on the water. But, when they get fully developed, the adult black flies will free themselves from their pupal case, rise to the water surface on a bubble of air, and fly away.
The Cnephia pecuarum is a serious livestock pest during the spring near the Mississippi River. As per the study, some species of large black fly have also killed the horses and mules either with bloodsucking bites or by smothering. This may especially occur when the nostrils of animals are blocked by the black flies. The species of black flies appearing during spring is Simulium meridionale, which attacks bird combs and wattles. In order to stay away from the Black fly, repellents and grease or oil smears are preferred to use.
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Habitat Of Black Fly
Usually, the Black flies depend on lotic habitats, which are the aquatic flowering plants to get food to them. The Black fly species in the New Hampshire region will show two types of life cycles. One type of species will lay eggs during overwintering. These eggs will remain submerged in the streams over the winter and hatch in spring when water temperatures reach about 40˚ to 50˚F. During the spring or early summer, the larvae develop into the adult. Some black fly species have more than one generation per year.
Reproduction of Black Fly
The second type of black fly species will be in the larval stage during overwintering. Later the larvae hatch when the stream temperatures are falling and develop during the winter months. During the early spring, the larva attains pupa stage when water temperatures reach about 37˚ to 38 ̊F. The pupa enters into the adult stage between late April to May and again females start depositing eggs in water in May and June. These eggs will remain in the water till they hatch. Generally, biting black and yellow fly are abundant near the outlets of ponds and lakes, because of the abundant availability of food or warmer temperature.
In the New Hampshire region, only two species of black flies are consistently and abundantly biting human beings. The name of these species is Prosimulium mixtum and Simulium venustum. Black fly species, Simulium venustum, is also called “white-stockinged” black fly and they mainly emerge during early to mid-May in southern New Hampshire. In the north, they emerge during the late May to early June and can remain abundant until the end of June in some areas and even into July in higher mountain localities.
Simulium jenningsi, a species of black fly that emerges during the late season. And most of them are annoying along the larger rivers in northern New Hampshire in August and September.
These black flies cluster around the head in large numbers but they usually do not bite.
According to the research conducted by Portsmouth University in 1986–1987, the Simulium spp have high acidic conditions while compared to other species of Black flies. Such an acidic environment provides conditions suitable for bacteria to metabolise cellulose in other animals. Usually, the Insects cannot metabolise cellulose independently, but the presence of these bacteria allows cellulose to be metabolised into basic sugars. Through this method, the black fly larvae are acquiring the essential nutrients.
Life Cycle of Black Fly
The male black flies feed on nectars and the female black flies feed on blood meals. For the required blood meal, the black flies depend on domesticated animals, poultry and other animals. The blood meal of female flies helps them to lay eggs. Species of Black flies may be either univoltine or multivoltine, which means they have either one or more broods of offspring per year. Usually, black fruit fly prefer running water for breeding. Some large black flies live in the large fast-flowing streams, others in small, sluggish rivulets. Almost all the kinds of permanent or semi-permanent streams are occupied by some species of black flies. The huge black fly populations indicate the clean and healthy streams. Because many tiny black flies do not have the tolerance to opt for organic pollution. In such cases, New Hampshire is a well known clear stream. So plenty of little black flies are settled here and creating serious annoyance to residents and visitors.
The female black flies usually lay their eggs on vegetation in streams or scattered over the water surface. The eggs hatch in streams of water. Later larvae get attached to rocks, leaves, grass or other submerged objects that remain in the streams. The major feed for larvae is tiny bits of organic matter, which will be obtained by filtering the water. The matured larvae become pupa under the water and rise up to adulthood. Then the emerging adults ride through the bubbles of air to the surface and fly away. Usually, the adult black flies mate near the breeding site.
The adult female black soldier fly requires a blood meal for laying eggs, so, they begin their search for blood after matting. Once the female black fly fed and digested, they started to lay eggs in a suitable stream for their habitat. The black flies often take trout as prey during the emergence period. Some South African black flies species larva are also known as phoretic on mayfly nymphs.
Black Fly Controlling Methods
Only individuals cannot control the black fly larvae. Also, treating a small area or part of the stream will not eradicate the pest completely. All the little black flies increase the pest problem. To control the count of black flies, it is preferable to apply pesticides on the surface of the water. This method will create nuisance problems for black flies and are rarely confined to one location. Also, the state regulators do not permit individuals to completely eradicate the Black flies. Even an organisation requires a commercial license to apply pesticides to control breeding black flies.
Controlling the black flies in the adult state is not possible, but sometimes, it will provide temporary relief for people. While using fog to control adult flies may provide the best solution. But the sustained control is not possible using this method
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Bat Flies With Human
Only four genera of the black fly family Simulium, Prosimulium, Simuliidae, Austrosimulium, and Cnephia search for the people for their feed. But other species prefer to acquire feed from other mammals and birds. Simulium is the type genus that is widely spread over and remains as a vector for several diseases, including river blindness. Usually, the matured black flies disperse tens or hundreds of miles from their breeding grounds in fresh flowing water using their own power, They are assisted by prevailing winds and the complicating control efforts. These behaviours are creating more impacts on livestock.
The bites of black flies are shallow, they initially stretch their skin using teeth on the labrum and then abrading it with the maxillae and mandibles, cutting the skin and rupturing its fine capillaries. The saliva of black flies is also facilitated by powerful anticoagulants, this will increase the amount of feed and feeding time. Generally, the black flies prefer daytime to have their feed.
Bites of Black flies may create itching, localized swelling and inflammation. Swelling is the sign of an individual's immune response, and irritation may persist for weeks. Sometimes, black fly causes "black fly fever", with headache, nausea, fever, swollen lymph nodes, and aching joints.
Part of World Affected By Black Fly Population
The wetter parts of the Northern latitudes of North America including Minnesota, New England, Canada, and the Upper Peninsula of Michigan will have a large number of tiny black flies population during the late April to July. Little black flies also create a nuisance to humans engaging in common outdoor activities, such as gardening, boating, camping, and backpacking. They are also spread over in the mountain areas of North America.
Usually, the black fruit fly in Canada is causing huge weight loss in cattle and sometimes black flies are responsible for the death of the cattle.
Pennsylvania, a country in North America, is operating large single black fly control programs. Through these programs, both the resident people and tourists of this country are availing benefits.
Simulium posticatum is the scientific name of Blandford fly, which are widely found in England and are creating public health problems in the area around Blandford Forum and Dorset. This is mainly due to the large numbers and the painful lesions caused by its bite. Later, they are eventually controlled by carefully targeted applications of Bacillus thuringiensis israelensis.
The Black fly species Austrosimulium australense and A. ungulatum are the actual sandflies in New Zealand.
Various parts of Scotland are facing nuisance and bites of various species of black flies from May to September. Variety of bat fly species are found mainly in mixed birch and juniper woodlands, and at lower levels in pine forests, moorlands, and pastures. These species usually target the head, neck and back of human beings and they frequently land on legs and arms.
According to the latest study during 2016, About 35 species of preimaginal black flies were discovered from Peninsular Malaysia, which includes Simulium digrammicum. Earlier, Simulium digrammicum was considered a locally extinct species.
FAQs on Black Fly
1. Are Black Flies Harmful?
The black soldier fly has a special characteristic that they can fly up to 10 miles to search for their blood. Usually, the black fly does not transmit diseases to human beings. But the injury developed by the black fly bites can create a threat for the livestock. Also, the threat of black flies in the house is high during the late spring and early summer.
2. What Happens When a Black Fly Bites You?
Usually, Blackflies prefer to bite near the head or face of human beings. They bite and leave a small puncture wound, and they may result in anything from slight swelling to a swollen bump the size of a golf ball. The bites of black fly may create nausea, headache, fever, and swollen lymph nodes.
3. What Does Black Fly Cause?
In some rare cases, the black flies are known to cause exsanguination, which is the death of organisms due to the loss of blood. The exsanguination may occur due to extreme rates of biting. Sometimes, the saliva of the black and yellow fly can cause a condition known as "toxic shock" in livestock and poultry, which may lead to death.
4. What Causes Big Black Flies in Your House?
The black flies in houses are common when small animals such as mice, rats, squirrels or birds die within a wall, ceiling or floor void. They may create a bad odour, which will attract the black flies in the house. Later, these flies will find the hidden carcass and lay eggs on the dead animals. The eggs will hatch into larvae or maggots, which will find their feed on the carcass.
5. Can Black Flies Kill You?
The flies may enter into the noses, ears and mouth of the human being, which may cause further discomforts. A large black fly can kill domestic animals, poultry and exotic birds. According to US researchers, the tiny black flies are not transmitting any diseases to human beings, but death may occur due to allergic reactions.
