The tsetse fly is a tsetse fly. tsetse

tsetse fly

It is also translated as a sting fly.

There are about 2 1 species of African blood-sucking insects, which can spread human sleep diseases and similar diseases of livestock-African trypanosomiasis. Tsetse flies feed on the blood of human beings, domestic animals and wild prey. Widely distributed, living in human settlements and agricultural areas in some sub-Saharan areas.

All tsetse flies are similar in appearance. The body is stout, with sparse mane, usually larger than the housefly, with a body length of 6? 16 mm (0.2? 0.6 inches). Yellow brown to dark brown. The chest is gray and often has dark stripes. There may be stripes on the abdomen. A firm puncture suction device is usually horizontal, with the tip pointing downward when biting. When resting, the wings are flat on the back. Each antenna has a bristle-like antenna antenna, which has a long row of branched hairs, which is different from other flies.

The life span of tsetse flies is 1? Three months. Larvae develop independently in the female uterus. Eggs hatch in females, and larvae feed on nutrient solution secreted by a pair of mammary glands on the uterine wall. Larval development is divided into three stages, which takes about 9 days. If the female flies can't suck enough blood, they can only give birth to immature larvae. If the female fly is full of blood, she will give birth to a mature larva every 10 day in her life. After landing, the larvae burrow into the soil and pupate within 1 hour. A few weeks later, it grew up.

Tsetse flies are usually found in woodlands, but when attracted by host animals, they also fly to open grasslands for short distances. Lipfish has important medicinal value and mainly grows in dense plants beside streams. On the other hand, tsetse flies in East Africa feed in more open woodlands. Both sexes suck blood almost every day, and their eating activities are particularly active in warm times. Most tsetse flies stop feeding after sunset or when the temperature is below 15.5℃(60℉). Among the tsetse flies that feed on human blood, males account for more than 80%, and females usually feed on the blood of large animals.

Only two species spread trypanosoma (a flagellated protozoa) that causes sleeping sickness in humans. Tsetse flies in Central Africa are the main carriers of trypanosoma Gambia, which causes sleeping sickness in all parts of West and Central Africa. East African tsetse fly is the main carrier of trypanosoma rhodesia, and sleeping sickness caused by this trypanosoma is found in the East African Plateau. East African tsetse flies also carry pathogens that can cause African trypanosomiasis in cattle and horses.

The most effective measures to control tsetse flies have always been to control environmental factors-killing wild prey of tsetse flies, reclaiming forest land and burning regularly to prevent overgrowth. Measures such as trapping tsetse flies, controlling tsetse flies with natural parasites and spraying pesticides on livestock have no effect. The effect of spraying after-effect pesticides into the air is still inconclusive.

There are about 30 species of tsetse flies, distributed in Africa and Arabia. Its body is smaller than a fly, with a body length of 6- 13 mm, yellow, brown, dark brown to black, a long beak and a horizontal extension. Both males and females feed on human blood and animal blood and are active day and night. At rest, the wings overlap each other and cover the back of the abdomen.

Sleeping sickness is caused by trypanosoma parasitic in human and animal blood. Trypanosoma is a unicellular flagellate with a wavy membrane on its side. When it proliferates in the blood, the trypanosoma's body becomes slender. When the host's resistance increases, the number of trypanosomes in the blood decreases, and most trypanosomes become short and thick.

At the early stage of trypanosoma invading human body, it parasitized in lymph and blood, causing most lymph nodes, splenomegaly and myocardial inflammation. Several years later, in the late stage, some people invaded the cerebrospinal fluid of human body after 2 ~ 4 weeks and developed meningitis. Patients have no desire, trembling, convulsions, and finally drowsiness and lethargy, and usually die in about 2 years.

When tsetse flies suck the blood of sleeping patients or sick animals, trypanosomes enter the intestines of flies and multiply, then transfer to the mouth and enter the salivary glands. When tsetse flies bite people again, trypanosoma will enter the human body with saliva.