Sandfly seed
The sandfly turned from an egg into a worm and grew wings into a moth. When it flies as a moth, it is as big as a bite and half as big as a mosquito. There are many species of sandflies, some of which only exist in Xinjiang. The male feeds on plant liquids, and the female specializes in cannibalism. It is a virus disseminator, and it brings the virus into the human body when it sucks human blood. The virus didn't break out until it had been lurking in the human body for half a year. It was characterized by fever, sweating, fear of cold, general malaise and loss of appetite. Later, it caused bleeding in the nose and gums, anemia, hepatosplenomegaly, blackened skin, and even bronchitis, tuberculosis, or death.
brief introduction
Phlebotomus. The English name is sand flies, which belongs to Coccidae (now a separate Phlebotomus family has been established! Note: It used to be an insect belonging to the family Lepidoptera, which is the vector of kala-azar!
Sand flies belong to Diptera, Nematocera and Phlebotomidae. More than 600 species are known in the world, and more than 40 species (subspecies) have been reported in China.
morphological character
Adult worms are grayish yellow or light gray, with a body length of1.5 ~ 4.0 mm and a dense coat of fine hairs (Figure 18-7). The head is spherical. The compound eye is big and black, and there is no single eye. The antenna is slender and divided into 16 nodes. Mouth is thick and short, about the same length as the first class, and it is a piercing and sucking type. Tentacles 5 nodes, bent downward and backward. There are mouthpieces and color plates in the mouth, and pharyngeal nails in the pharynx. The chest and back bulge is hunchbacked. A pair of wings and a balance bar. The wings are long and narrow, with sharp ends and are covered with fine hairs. When resting, the wings stand up and are separated from the left and right, which is about 45? Horn. The feet are slender. Most of the hairs on the back of the 2nd-6th abdominal segment are erect (Physopa) or recumbent (Physalis). At the back end of abdomen, female wren has 1 pair of tail whiskers, and there is spermatic sac in abdomen; Male wrens form complex external genitalia. The morphology of adult's oral nail, color plate and pharyngeal nail, male external genitalia and female seminal vesicle are important basis for classification.
life habit
Sandfly is a completely metamorphosed insect. The life cycle includes four stages: egg, larva, pupa and adult (Figure 18-7). The egg is oval, with striated shell, about 0.4mm long and brown. Under suitable conditions, larvae hatch in 6 ~12 days. Larvae is small caterpillar-like, white. Divided into 4 ages. 1 larval length1.0 ~1.5 mm, and the 4th larval length is about 3 mm.. There are tail bristles at the tail end of larvae, 1 instar larvae 1 pair, and 2 pairs of 2-4 instar larvae. Larvae feed on organic matter in soil, and generally pupate in 25-30 days. There is no cocoon outside the pupa, and the skin shed by the 4th instar larva is attached to the tail end, which is light yellow and about 4mm long. Pupa does not eat or move, and it takes about 6 ~12 days to emerge as an adult. Adults can mate within12 ~13 hours after emergence. Male wrens can mate for 2-3 times, while female wrens usually mate once in their whole lives, mostly before blood feeding, and lay eggs 3-4 days after blood feeding, and they can lay eggs many times, with 60-80 eggs in their whole lives. The time required for the whole life history is related to the species, temperature, humidity and food sufficiency. 21~ 28 c is the suitable temperature for the development of sandfly, and it takes about 6 ~ 8 weeks from egg development to adult. 68% of the 4th instar larvae of Ampelopsis sinensis have diapause until pupation in the following spring. Female wrens can survive 1 living environment
1. The larvae of sandfly at all stages live in the soil, especially in the ground about10 ~12 cm. Places that are hidden, with appropriate temperature and humidity, loose soil and rich in organic matter, such as human houses, livestock houses, toilets, caves, cracks in walls or caves, are all suitable for the breeding of sandfly larvae. 2. Feeding males do not suck blood, but feed on plant juice, while females suck blood. The blood-sucking objects of different species of sandflies are different. The sandflies mainly suck the blood of humans and mammals, while the sandflies mostly suck the blood of birds, amphibians and reptiles. 3. Living and active adults usually live in dark, damp and sheltered places indoors and outdoors, such as corners, cracks in walls, barns, cellars, caves, bridge opening and caves. The same species of sandflies can show different habitat habits due to different environments. For example, the sandfly is a domestic type in the plain area, inhabiting in human houses and livestock houses; In the northwest mountainous areas and the Loess Plateau, it is a wild type, which is more common in various caves and empty kilns. The flying ability of sandflies is weak, generally flying in a short distance by jumping, and the range of activities is generally within 30 meters in diameter, and the activity time usually starts at dusk and stops before dawn. Domestic species mainly live indoors. Species inhabiting desert rat holes fly out at dusk and gradually fly back to the holes after midnight. 4. Seasonal fluctuation and the seasonal distribution of wintering sandflies are related to the local temperature change, usually 1 year appears for about 3 to 5 months. Home-dwelling Chinese sandfly first appeared in the middle and late May, peaked in the middle of June, and disappeared in the middle and late August. Most of them breed 1 generation a year, and a few of them have 2 generations. Most sandflies spend the winter as 4th instar larvae hiding in shallow soil within lOcm.
Important infectious diseases
1. Phlebotomus chinensis chinensis about 3.0 ~ 3.5 mm long, with pale yellow hair, undeveloped mouth nail and colorless plate. There are many sharp teeth in the anterior and middle parts of the pharyngeal nail, and there are several transverse ridges at the base. Seminal sac spindle-shaped, segmented, but incomplete; The length of the capsule tube is 2.5 times that of the capsule body. There are five long hairs in the second section of the upper arm of the male wren, two at the top and three near the middle, and the length of the reproductive filament is about five times that of the sperm injector (figure 18-8). It is widely distributed, ranging from north latitude18 to 42 and east longitude102 to124. It is an important vector of kala-azar. 2. The type of P.C. Longituctus is similar to a named subspecies, and the difference between them is that the length of spermatic sac of this subspecies is 5.8 times of the length of sac body, and the length of reproductive filament is about 10.6 times of that of sperm injector. Only distributed in Xinjiang, China.
[Edit this paragraph] Relationship with disease
Besides biting people and sucking blood, sandflies spread visceral leishmaniasis in China. D 谠? Guess? The pathogen of visceral leishmaniasis is Leishmania donovani, and sandfly is the transmission medium. (For the relationship between sandfly and pathogen and the distribution of the disease, see the relevant chapters in this book). The main media in China are: 1. Ampelopsis sinensis is the main media except Xinjiang, western Gansu and Ejina Banner in Inner Mongolia; 2. The sandfly is the media in the old residential areas in southern Xinjiang; 3. Alexander sandfly is the media in Xinjiang. 4. Wushi Bailing is a media in desert areas such as Xinjiang and western Inner Mongolia (Ejina Banner).
Prevention principle
Sandfly has a small range of activities and weak flight ability, so killing adult sandflies with drugs is the main control measure. Insecticides for killing adult flies include deltamethrin, cypermethrin and malathion, which can be used for indoor residual spraying or fumigation with dichlorvos. Environmental control measures include keeping indoor, barn and poultry pen clean, and removing the garbage in the surrounding environment to eliminate the breeding ground of larvae. Killing larvae with Bacillus thuringiensis (H- 14) is effective. Personal protection can use fine-hole mosquito nets, screen windows, rubbing repellents (deet, mosquito repellent dew) or smoking with mugwort.
Sandfly seed
Author: Liu Ying Source: New Overseas Chinese News Network Release Time: 2008/06/20 17:43:55.
There is an insect called sandfly, which turns from an egg into a worm and grows wings into a moth. It is as big as a small bite when it flies as a moth. Maybe some people have never seen a small bite, which is half as big as a mosquito, so it is hard to detect when it flies around. There are many species of sandflies, some of which only exist in Xinjiang. The male feeds on plant liquids, and the female specializes in cannibalism. It is a virus disseminator, and it brings the virus into the human body when it sucks human blood. It took half a year for the virus to lurk in the human body before it broke out. It showed fever, sweating, fear of cold, discomfort and loss of appetite. Later, it caused bleeding in the nose and gums, anemia, hepatosplenomegaly, blackened skin, bronchitis and tuberculosis ... and then it died. The disease is called kala-azar, which spread wildly in Europe 500 years ago and killed countless people.
My daughter developed the early symptoms eleven months after birth, with nosebleeds and convulsions. After I took her back to the hospital for examination, the doctor said that she must have been bitten by a sandfly, saying that she had kala-azar, and if she was not treated in time, she would die of other diseases! I asked the doctor how to save her. "It's early, but it's still here. It's good to inject' Stimheck'." "Then give her an injection!" I want to kowtow to the doctor. "It's a pity that our group hospital doesn't have that medicine" is not more deadly! "Don't worry, I'll contact you to see if the 51 ST regiment hospital has it." ..... "Five? Ok, I'll ask my parents to get it. " I heard hope from the doctor's phone call.
That "regiment" is compiled by the Production and Construction Corps. We are fifty regiments, which are twenty-five miles away from the fifty-one regiments. I don't know how to run back and forth in three hours. Five "Stimheck" were injected into her daughter within one week, and she came back to life. The wife who accompanied her to the hospital said, "Look, you were sweating all day, why didn't you think of going home and pedaling with your bike?"
My daughter was saved, but the sequela of falling for a long time: she would faint easily. Once she was foaming at the mouth and fainted, I carried her on my back and ran to the regimental hospital more than ten miles away. When I got to the hospital, I heard her talking on my back, "Dad, the moon!" Looking up, yes, the moon lit up the night sky, and my daughter came alive again, alive and kicking.
Still not at ease, let the doctor have a look. The doctor touched her forehead and said, "Nothing. Next time you encounter this situation, touch her head first. If you don't have a fever, you won't have time to run to the hospital, and you will be fine when you wake up. "
When my daughter fainted again, my wife really pinched her "middle man" with her nails to bring her back to life, but a nail under her mouth was printed for many days, for fear that it would affect her face if she grew up, we changed a new photo: my wife always pinned a big needle on her chest and my hat to prick the "middle man".
When my daughter was two years old, we went back to Beijing to visit relatives and brought some Panamanian bananas when we returned to Xinjiang. My daughter is chubby, which appeals to the passengers in the carriage. She is also good at making friends. While we were not paying attention, we broke off two big bananas and took them to the next carriage to eat with a child. Not long after, I heard the child's parents exclaim, "Oh, no, is there a doctor!" I looked over and found that my daughter was foaming at the mouth and fainted. I asked the parent to know that she had eaten a Panama banana in one breath. I had a needle on my hat. I pulled it out and pricked her, patted her on the back, and after spitting out half a banana, I was alive and kicking again, which scared the passengers to death and made them happy.
My daughter's kala-azar sequelae can only be removed when she is five years old. We have been pinned for four years. I really hate sandflies.