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In biology, flies are typical "completely abnormal insects". At the end of 1970s, there were 132 families and 120000 species of Diptera in the world, including 34000 species of flies in 64 families. Fuzhou has 4 families, 38 genera and 74 species. The main fly species are housefly, city fly, Lucilia sericata, Chrysomya megacephala and so on.

English name: fly

Flies have the physiological characteristics that they can lay eggs for life once they mate. A female fly can lay eggs 5-6 times in her life, and the amount of eggs laid each time is about 100- 150, up to about 300 at most. It can breed 10- 12 generations within one year.

Flies mostly feed on decaying organic matter, so they are more common in places with poor sanitary environment. Flies have sucking mouthparts, which will pollute food and spread diseases such as dysentery.

In the ecosystem, fly larvae play an important role as decomposers of animals and plants. Adults of flies like to eat sweet substances, so they can also replace bees to pollinate crops and improve varieties.

In clinical medicine, live fly maggots can be inoculated into wounds to sterilize and debride and promote healing.

Protein-rich fly maggot is an important bait and feed, which can be produced in factory.

[Edit this paragraph] Life history

Its life goes through four stages: egg, larva (maggot), pupa and adult, and the morphology of each stage is completely different. The breakdown is as follows:

The life span of a fly is 1. Egg: the egg is milky white, banana-shaped or oval, about 1 mm long. There are two ridges on the back of the eggshell, and the membrane between the ridges is the thinnest, from which the larvae emerge when hatching. The development time of egg stage is 8 ~ 24 hours, which is related to environmental temperature and humidity. Eggs do not develop below 65438 03℃ and die below 8℃ or above 42℃. In the following range, the incubation time of eggs is shortened with the increase of temperature: 20 hours at 22℃; At 25℃, it takes 16 ~ 18 hours; At 28℃, it takes 14 hours; At 35℃, it only takes 8 ~ 10 hour. The humidity of growth substrate also affects the hatching rate of eggs: when the relative humidity is 75% ~ 80%, the hatching rate is the highest; When it is lower than 65% or higher than 85%, the hatching rate is obviously reduced.

2. Larvae: Larvae of flies, commonly known as maggots, has three ages: 1 larval body length 1 ~ 3 mm, and only one posterior lobe. After molting, it becomes 2 nd instar, 3 ~ 5 mm long, and the anterior and posterior valves are 2-cleft. The molting again is three years old, with a body length of 5 ~ 13mm and a 3-cleft posterior flap. At the age of 1 ~ 3 years, the body color of fly maggots changes from transparent and milky white to milky yellow until they mature and pupate. The 3rd instar larvae are oblong, conical, tapering at the front end and truncated at the back end, with no eyes and no feet. The life characteristics of fly maggots are that they like to make holes, are afraid of strong light, and live in the shadows of breeding materials all day long. It has a variety of feeding habits, and all kinds of rotten and fermented organic matter are delicious. Larval stage is a key period in the life of flies, and its growth and development is directly related to the individual size and reproductive efficiency of breeding flies.

The main factors affecting the growth and development of fly maggots are as follows:

① Temperature: Its level is directly related to the development time of fly maggots. The optimum environmental temperature (moderate temperature) is 34 ~ 40℃, and the development period can be shortened to 3 ~ 3.5 days. When the temperature is 25 ~ 30℃, the development duration is 4 ~ 6 days; When the temperature is 20 ~ 25℃, the development duration is 5 ~ 9 days; When the temperature is 16℃, the development duration is as long as 17 ~ 19 days. The lowest temperature during development is 8 ~ 12℃, and it will die if it is higher than 48℃.

② Humidity: 1 ~ 2-year-old maggots have a suitable environmental humidity of 6 1% ~ 80% and an optimum humidity of 7 1% ~ 80%. The suitable humidity of the third instar fly maggot is 6 1% ~ 70%, and it can't develop normally if it exceeds 80%. It can be seen that the development of fly maggots needs a certain degree of humidity, but the higher the better. In production practice, the suitable humidity is 65% ~ 70%; When it is lower than 40%, the development of fly maggots is stagnant, pupation is rare, and even fly maggots die.

③ Food: An important ecology of fly maggots is omnivorous, and they feed on the spot in their habitat. Someone once found 76,400 fly maggots and pupae in 1.5 square meters of pig manure! Protein in animal feed, plant feed and even microorganisms are all nutrients that fly maggots like to ingest. The quantity, quality, fermentation temperature and even water content of food are directly related to the development effect of fly maggots. The 3rd instar fly maggots stop feeding when they mature, and often leave the breeding ground at low temperature and humidity of 15 ~ 20℃ and drill into the nearby loose soil to pupate. Someone once found thousands of housefly pupae in the cracks in the broken cement floor of a winery wall.

④ Ventilation: Ventilation is beneficial to the growth and development of fly maggots. In the garbage dump, fly maggots are often distributed in corners and walls with large gaps.

Mastering the growth characteristics of the above-mentioned fly maggots can be used to guide production practice and is of great benefit to improving the breeding efficiency of fly maggots.

3. Pupa: Pupa is the third metamorphosis in the life history of flies. It is barrel-shaped, that is, it surrounds the pupa. Its body color changes from light to dark, and finally becomes chestnut brown, with a body length of 5 ~ 8 mm, and the pupa shell is constantly deformed. Once the embryonic form of the fly is formed, it enters the eclosion stage. During eclosion, flies alternately expand and contract by the frontal sac of the head, squeeze out the head end of the pupa shell and climb out, and reach the surface through loose sand or other cultures. From pupa to eclosion, it is called pupa stage.

The external factors affecting the growth and development of pupae mainly include:

① Temperature: After the 3rd instar flies mature, they tend to pupate in a slightly lower temperature environment. But when the temperature is lower than 65438 02℃, the pupa stops developing. When the temperature is higher than 45℃, the pupa will die. In a suitable range, with the increase of temperature, the pupal period is shortened accordingly. At 16℃, it takes 17 ~ 19 days; At 20℃, it needs 10 ~ 1 1 day; At 25℃, it takes 6 ~ 7 days; At 30℃, it takes 4 ~ 5 days; At 35℃, it only takes 3 ~ 4 days, which is the best development temperature. Pupa is characterized by its cold tolerance. According to the experiment, the pupa of housefly returned to normal room temperature after 4 days in the refrigerator with the temperature of 65438 0℃ and the environmental humidity of 85%, and the emergence stage was only 65438 0 days later than the normal pupa stage. Cold storage for 3 days in the above environment will not reduce the eclosion rate.

(2) Humidity: According to the experiment, the optimum humidity for pupa development is 45% ~ 55%, higher than 70% or lower than 15%, which will obviously affect the normal emergence of pupa. If the pupae are soaked in water, the longer the time, the lower the pupation rate of fly maggots and the lower the emergence rate of pupae. Someone once fished out 1000 fly pupae from liquid garbage. After being transferred to a dry environment, 1 failed to emerge as adults.

It is worth mentioning that if the nutrients in the culture of fly maggots are insufficient, the maggots will barely pupate under the condition of incomplete development, and the pupae can hatch into flies, but more than 95% of adult flies are males, who only eat food and do not lay eggs, and all die within a week or so. Therefore, maggots used for seed storage and pupation must be fertilized with enough nutrients, and the greater the female ratio. Only when there are more female flies can the amount of eggs laid be guaranteed and the yield be stable.

4. Adult flies: Adult flies with pupa emergence need to go through several stages of "static-crawling-stretching-spreading wings-body wall hardening" before they can develop into adult flies with the ability of flying, feeding and reproduction. Musca domestica, which has just pupated, has a soft and light gray body wall, its wings have not been unfolded and its frontal sac has not been retracted. Later, the wings spread, the epidermis hardened and the color deepened. 1 ~ 1.5 hours later, the wings can fly. At 27℃, adults began to move and feed 2 ~ 24 hours after emergence. Its ecological habits are as follows.

(1) feeding habits and longevity

The feeding habits of flies depend on their species. There are those who specialize in nectar and plant juice, and those who specialize in cannibalism, animal blood or animal wound blood and eye and nose secretions. Common houseflies, Chrysomya megacephala, Lucilia sericata, Calliphora, Hemp flies, etc. belong to omnivorous flies, that is, organic substances in human food, livestock and poultry excreta, kitchen waste and garbage are widely eaten. They have a strong preference for the taste of sugar, vinegar, ammonia and fishy smell. According to the research, if only the female flies are provided with water, sugar and carbohydrates, although they can grow, their ovaries cannot develop and lay eggs; Only by feeding protein with food or a variety of amino acids can you lay eggs normally. If female houseflies are fed with royal jelly, the prophase of oviposition can be shortened and the amount of oviposition can be increased.

The factors that affect the life span of flies are temperature, humidity, food and water. The optimum temperature is 25℃ ~ 33℃, and the air humidity is 60% ~ 70%.

Female flies live longer than male flies, with a life span of 30 ~ 60 days; Under laboratory conditions, it can be as long as 1 12 days. Flies can survive for half a year under the condition of low temperature and overwintering.

Flies are very adaptable. The breeding of flies can be roughly divided into human manure, livestock manure, corrupt animals, corrupt plants, garbage and sewage. Fly maggots have strong adaptability, and almost all of the above six species can reproduce, especially in livestock manure and fermented plants, followed by human manure and corrupt animals.

(2) Activities and habitats

Flies are daytime active insects with obvious phototaxis. At night, it stays still. The activity and habitat depend on the species, season, temperature and region of flies. In some seasons, stable rot flies, summer flies and city flies also invade houses. Chrysomya megacephala, Lucilia sericata, Calliphora, Bactrocera dorsalis, Hemp Fly, etc. Mainly active outdoors.

The activity of flies is greatly influenced by temperature. It can only crawl at 4 ~ 7℃, fly at 10 ~ 15℃, feed, mate and lay eggs above 20℃, especially active at 30 ~ 35℃, stop moving at 35 ~ 40℃ due to overheating, and die at 45 ~ 47℃.

Flies are good at flying. The flying speed can reach 6 ~ 8 kilometers per hour, and the maximum flying time is 8 ~ 18 kilometers per day and night. However, they usually move within the radius of breeding ground100 ~ 200m, and most of them do not exceed1~ 2km.

The way flies overwinter is quite complicated. It can not only overwinter in pupa state, but also overwinter in the form of fly maggots and adults. In the northern cold and temperate regions, there are no active houseflies in nature, but there are still adults in artificially heated rooms, and vegetable greenhouses often become the birthplace of a large number of flies in the next spring. In the south of the Yangtze River and parts of North China, the average temperature in winter is below 0℃, so flies can spend the winter skillfully as pupae, and maggots of dormant female flies covered with livestock manure can be found in a few areas. In the subtropical region of South China, the average temperature is above 5℃, and flies can continue to reproduce without dormancy.

(3) Separation of men and women

1. From their individuals, the smaller individuals in the group are generally male, and the larger individuals are generally female; Look at their bellies: the bellies of male flies are small and flat, while those of female flies are big and round; 3. Look at their asses. They are divided into females: the buttocks of male flies are round, while those of female flies are pointed.

(4) mating and reproduction

At suitable temperature, the male housefly can mature and mate 24 hours after emergence and 30 hours after emergence. The mating time is usually from 5 am to 7 am. Sensitive sense of smell, sex pheromone and vision are all important factors to promote the mating of male and female flies. A pair of mating houseflies can stay in one place for a long time, crawl and fly together, and the effective mating time is as long as 1 hour. Most houseflies mate only once in their lives. The semen of a male fly can be stored in the fertilization sac of a female fly for a long time, which can stimulate oviposition and keep the fly eggs fertilized for 2-3 weeks without mating with another male fly. This is rare among other insects. This is an important reason why flies are prolific.

The peak spawning period is from 17: 00 to 19: 00 every day. The length of the female fly's pre-spawning period (i.e. the time from emergence to first spawning) is closely related to the environmental temperature: 9 days on average at 15℃, only 1.8 days at 35℃, and no eggs can be laid below 15℃. After mating, female flies often climb into reproductive gaps such as human and animal feces, and extend their oviposition tubes to the depths of reproduction to lay eggs, so as to fully protect eggs.

The fertility of flies is amazing. According to the observation, the number of eggs laid by houseflies in the laboratory is about 100, and 1 20 batches of eggs can be produced by each female, totaling 600- 1000. In nature, each female fly can lay eggs in 4-6 batches in her lifetime, with an interval of 3-4 days. The number of eggs laid in each batch is about 100, and the life span is 400-600. Even in North China, houseflies can reproduce 10 ~ 12 generations a year. According to the most conservative estimate, each female fly can produce 200 offspring, so 100 female flies only need 10 generation, and the total number of flies bred will reach 2 trillion!

5] Natural enemies

Although flies have strong reproduction and prosperous families, 50% ~ 60% of their offspring die prematurely due to natural enemies and other disasters. There are three kinds of natural enemies of flies: one is predatory natural enemies, including frogs, dragonflies, spiders, mantis, ants, lizards, geckos, insect-eating flies, birds and so on. Chicken manure is the breeding ground of domestic flies and stable flies, but there are often malignant giant mites and salamanders, which will prey on fly eggs and maggots in the manure. Second, parasitic natural enemies, such as wasps and wasps, often lay eggs in maggots or pupae, and then feed on maggots and pupae after hatching larvae. The results showed that 60.4% wasp pupae were invaded by parasitic wasps and died prematurely. The third is the natural enemy of microorganisms. Japanese scholars have found that Bacillus Morita can inhibit the reproduction of flies, and China scholars have also found that if the spores of "monospora flies" fall on flies, flies will be infected with monospora flies. These are worthy of the attention of fly maggot farmers.

Caging flies in ordinary houses is a widely used technology in fly farms in China in recent years. This technology requires indoor heating facilities, otherwise, when the indoor temperature is lower than 27℃ in autumn, winter and spring, the fecundity of flies will be seriously reduced. When the room temperature is low, especially in the north, flies have to pupate to prevent insects in winter, which leads to the interruption of fly reproduction and the obvious decline of economic benefits. Breeding flies in plastic greenhouse has successfully solved this problem, which can make flies produce continuously all year round and improve the breeding benefit several times. It has become a very promising technology.

Flies have the following requirements for temperature, humidity and light:

The optimum temperature for flies is 27℃ ~ 30℃. Flies can move at 8 ~ 12℃, but they can't mate or stand on food. They can only land on the ceiling and wall, motionless. 5 degrees below zero, died in 3 ~ 5 days. The temperature required by fly larvae is higher than that of adults, and the optimum temperature for its fastest development is 35℃. Stop exercising at minus 1 ~ 2℃ and die at minus 5 ~ 6℃. When the temperature is 45 ~ 55℃ too high, its rising speed is reduced by half compared with that at normal temperature. It is suitable for fly larvae to require food temperature of 30 ~ 35℃. In terms of humidity, adults require indoor humidity of 55% ~ 60%. When the humidity is too high, the legs and bodies of flies are easy to get wet, which hinders activities. The humidity required for larval growth is 65% ~ 70%. Flies like to move in bright places, and the greater the brightness, the greater the activity. The room where flies are artificially raised should be equipped with a lighting device, and the daily illumination should be above 10 hour.

[Edit this paragraph] Injury

Flies are harmful to human beings because they carry a variety of pathogenic microorganisms. Flies have hair on their bodies, and the foot pads can secrete mucus. They like to crawl for food in human or livestock feces, sputum, vomit and corpses, and are very easy to attach a large number of pathogens, such as Vibrio cholerae, Salmonella typhi, Shigella dysenteriae, hepatitis B, polio, hepatitis A and ascaris eggs. Often stay on the human body, food, tableware, and have the habit of rubbing feet and brushing your body when you stop. Bacteria attached to it will soon pollute food and tableware. When flies eat, they spit out the crop liquid first, dissolve the food before inhaling, and they can eat, vomit and pull. In this way, the pathogen originally eaten in the digestive juice will be spit out together, polluting the food it has eaten, and people who eat these foods and use contaminated tableware will get sick. The prevalence of cholera, dysentery and bacterial food poisoning is directly related to the spread of flies, but it is not without its merits. Without it, mankind will be trapped in a rotten place.

[Edit this paragraph] Prevention and control

1. Domestic garbage is packed in plastic bags and will be cleared every day. Don't stay in one place for a long time, and don't let flies come into contact with it to lay eggs.

2 trash cans (boxes, cars) must be stamped and removed in time.

3. Eliminate the garbage and sanitary corners in front of and behind the house, inside and outside the unit in time.

4 restaurants, stalls and places where food exists should have fly prevention and fly killing facilities.

5. Urban residents are prohibited from raising poultry and livestock.

6. Don't use the viscera and bones of chicken, duck and fish as flower fertilizer.

7. Hotels, restaurants and restaurants should have perfect fly prevention and killing facilities, and the garbage should be sealed and removed in time.

8. Natural enemies can be used for control. For example: spiders, geckos and so on!

[Edit this paragraph] Five ways to fly skillfully

1. vinegar flies.

Spray some pure vinegar indoors and the flies will stay away.

2. orange peel fly repellent method

Burning dried orange peel indoors can not only drive away flies, but also eliminate indoor odor.

3. How to repel onion flies

Put more chopped onions, shallots, garlic, etc. In the kitchen. These foods have a strong pungent smell and can drive away flies.

4. Method of repelling tomato flies

Putting a pot of tomatoes indoors can drive away flies.

5. residual tea drives away flies

Sun-dried tea leaves, burned in toilets or ditches, can not only repel mosquitoes and flies, but also remove odors.

[Edit this paragraph] "8864 tricks" for killing flies by human beings

First, the most primitive: pat a dead fly with a fly. The fly killing effect of this method depends largely on the operator's skill. Advantages: low cost. Disadvantages: the fly killing effect depends largely on the fly killing technology; Will produce pollution. Recently, electronic fly swatter appeared, which overcame the shortcomings of pollution of traditional fly swatter, but the cost of fly swatter increased.

Second, the fastest: pesticides kill flies. At present, there are two kinds of fly killers on the market: stomach poison and contact poison. ① stomach toxicity. It enters the digestive system through the mouth of insects and plays a toxic role, such as trichlorfon. (2) contact killer. After contact with epidermis or appendages, it seeps into the insect body, or corrodes the wax layer of the insect body, or blocks the valve to kill pests, such as pyrethroids and mineral oil emulsions. Killing flies will pollute the environment at the same time, especially stomach medicine, which is not suitable for food factories with food production and pharmaceutical factories with drug production.

Third, all-weather ultraviolet trapping and killing. Flies belong to phototactic animals and are particularly sensitive to ultraviolet rays. Using this feature, humans invented the ultraviolet light trap, and the power grid outside the ultraviolet light can make flies electrocute and die. Advantages: no pollution; You can kill flies day and night. Disadvantages: it will produce sparks and is not suitable for flammable and explosive places.

Fourth, the safest: put sticky fly paper. When a fly accidentally hits or falls and stops, it gets stuck and can't move. This method is only suitable for places where there are many flies, and there is no need to strictly kill flies.

Fifth, everything comes to nothing-"strong walls and clear fields." The longest life span of flies is 15 days. If they don't get food for a long time, they will die soon. Therefore, taking good care of all food and disposing of garbage is a fatal blow to flies.

Sixth, the trump card-wet rags kill flies. After throwing the rag with water, the kinetic energy is large, so the range is long, the coverage area of the rag is large, and the hit rate is increased. After a period of practice, the rag thrown by the practitioner will become a fly's nightmare.

[Edit this paragraph] Life span

The life span of a fly can reach about 1 month in midsummer. But at low temperature, its life can be extended by 2 to 3 months, and it can hardly move below 10 degrees, and its life is longer. The life span of an adult fly is 15 ~ 25 days, which is 25 ~ 70 days if the larval stage and pupal stage are counted.

[Edit this paragraph] The life of a fly

1, adult

Body length is 5 ~ 8 mm, grayish brown, compound eyes are hairless and dark red, and the forehead width of male flies is1/4-2/5 of the eye width; The width of the female fly's forehead is almost equal to the width of a compound eye. The antenna is gray-black, short and flat, the antenna awn is short, the base is thick, and there are feathery hairs on both sides of the back and abdomen, reaching the tip of the awn, and the next one must be brown-black. Licking mouth type, short beak visible in appearance, consisting of three parts, the base beak is inverted cone, the middle beak is short cylindrical, and the end beak develops into two petals, called lip; The beak can expand and contract freely. There are four black longitudinal strips in the middle chest shield plate, cilia in the central depression of the front chest side plate, no bristle tufts in the front and rear ribs of the axillary flap, and hairs in the front and rear lower side plates of the rear air valve. The wings are transparent, the veins are brownish yellow, and the scales at the base of the main veins are yellowish white. The end of the fourth longitudinal vein bends sharply forward at an angle, and its end is close to the end of the third longitudinal vein. The feet are black with grayish yellow powder, and the abdomen is oval and yellow, especially on both sides of the base. There is a wide black longitudinal strip in the middle of the abdomen, and the first web of the abdomen has cilia. A fly has six legs (3 pairs), and the first pair is equivalent to the forelimbs of mammals such as humans, kangaroos, monkeys, bears and pandas. The back two pairs are thighs, which are used for support and strength, equivalent to the hind limbs of mammals such as humans, kangaroos, monkeys, bears and pandas.

Step 2: eggs

Eggs are banana-shaped, about 1mm long, milky white, with two ridges on the back of the eggshell, and the thinnest between them. When the eggs hatch, the eggshells crack here, and the eggs are often produced in pieces.

3. Larva

Larvae, commonly known as maggots, has no feet, and its craniopharyngeal bone, posterior flap, posterior flap fissure and terminal ventral nodule are common features of classification and differentiation. Larvae * * * 3rd instar: 1 instar larvae are 1-3mm long, with transparent body color, no anterior lobe and only 1 fissure in the posterior lobe; The second instar larvae are 3-5 mm, milky white, with 2-lobed anterior and posterior petals; The third instar larvae are 5 ~ 13 mm long, milky yellow, and the front and rear petals are 3-lobed, cylindrical and gradually taper from the middle to the front. The head is small, the mouth is hooked and claw-shaped, and the left and right sides are asymmetrical.

4. Pupa

The pupa is barrel-shaped and surrounds the pupa. It is about 6.5 mm long, yellow and white at first, then dark, and finally chestnut brown. There are 1 pairs of pupa petals between 1 and 2 abdominal segments.

[Edit this paragraph] Eating habits

Flies have a variety of eating habits, including sweet, sweet, sour and smelly. When they eat, they have to spit out crop liquid to dissolve the food. Their habit is to vomit and pull while eating. It is observed that when food is sufficient, flies defecate 4-5 times per minute.

Flies will also eat bacteria that are not good for them when they eat, so the method of "spitting while eating" is helpful to quickly eliminate bacteria. Generally speaking, it takes only 7~ 1 1 sec for flies to eat, absorb nutrients and excrete wastes. When encountering bacteria with rapid reproduction ability, the fly's immune system will emit two kinds of globulin, BF64 and BD2. Once exposed to bacteria, it will explode and "mutually perish together" with bacteria. The emission of these two globulins is always in tandem, appearing in pairs and never confusing.

It is worth pointing out that the killing power of BF64 and BD2 is several thousand times stronger than that of penicillin. If BF64 and BD2 can be extracted from flies for human treatment, it will bring good news to mankind.

[Edit this paragraph] The best way to kill flies

Fly is a completely abnormal insect, which has three stages in its life: egg, larva (maggot) and pupa. Flies have only one pair of wings for flying, and the other pair of wings has evolved into a balancer, so it is very difficult to catch flies. So the best way to kill flies is to deal with substances suitable for flies to breed. If the garbage is bagged (the bag should be intact and the bag mouth should be tightly tied), do not litter or urinate anywhere, and properly handle the pet feces.

Prepare a bottle with a long mouth, and put some things that flies like to eat, such as fish blood, in places where there are many flies, such as garbage dumps.

[Edit this paragraph] Kill rats and flies

There are mice in the house, and people often use rodenticide to kill them. The annoying mouse stopped making trouble and forgot to kill it. However, after 1-2 weeks, the constant appearance of flies will remind you to die for mice. Therefore, after killing rats, we should look for the dead rats in the corner, pack them in plastic bags and dispose of them.

[Edit this paragraph] Why do flies always "rub their feet"

The fly has no nose, but it has another taste organ, and it is not on the head and face, but on the feet. As long as it flies to food, first taste the food with the taste organs on the feet, and then eat it with the mouth. Because flies are greedy and like to fly around, they should taste everything they see. In this way, there will be a lot of food on their feet, which is not conducive to the flight of flies and hinders their taste. So flies rub their feet to get rid of food on them.

Because flies have this bad habit, they can be infected with many germs. If flies stand in feces and sewage and fly to food, they will leave germs on the food. In addition, flies have a worse habit, that is, they land on food, not only eat food, but also excrete feces, and put some live bacteria and parasitic eggs in the intestines on food. If people eat such food, it is easy to get sick, affecting their health and even endangering their lives.

The Fly is also an American science fiction horror film. There seems to be a sequel "Fly II", which tells a series of things that happened after a scientist had the genes of flies. I'm too lazy to find links to specific plots. I should find a lot.

In addition, there should be an aphrodisiac also called "fly".

[Edit this paragraph] Interesting story about flies

"Flies" on Australian paper money

Most people have a feeling of disgust when they mention flies. But Australian 50 yuan banknotes are printed with flies. Australians regard flies as "pets". Because this kind of fly is different from flies in other countries. Most of them live in the forest, feed on plant juice and do not carry any viruses and bacteria. This kind of fly is large, its whole body and wings are soft and golden yellow, and it doesn't make an annoying buzz when flying. So Australia's evaluation of domestic flies is: beautiful, clean and lovely. Flies have become one of Australia's export commodities, and they can get a lot of foreign exchange every year. In the two major ports of Sydney and Brisbane, a large number of containers full of flies are transported abroad every month for teaching and research by universities and scientific research units all over the world, and can also be used as bait for fishing enthusiasts and feed for fishing grounds.

Excerpt from Dahe Daily.

Overseas Edition of People's Daily (4th Edition, June 65438+1October 265438+1October 2000)

The mouthparts of flies

It belongs to sucking type: the upper and lower jaws degenerate, leaving only 1 pair of rod-shaped mandibular whiskers; The lower lip is specialized into a long beak, and the beak end expands into a 1 pair of lips with an annular groove. The base of the back of the beak is attached to the sword-shaped upper lip, the lower part of the beak is close to the flat tongue, and the two sides are closed to form a food passage.

Zheng, Higher Education Press, Guide to Zoology Experiment, Second Edition.

Page 52

Feeding of flies

There are many ways to raise flies. There are two ways to raise flies in plastic greenhouses:

One is to set up a three-dimensional gauze net in the greenhouse and raise flies in the net; The other is free-range cultivation in greenhouses, where a certain amount of straw and straw ropes are piled up, and each greenhouse is regarded as a cage. Compared with the previous methods, this method has the advantages of large investment, large area and low feeding density. Generally, in the cultivation mode of setting gauze in the greenhouse, a plastic greenhouse with a length of 20 meters, a width of 4 meters, a low wall height of 2 meters and a high wall height of 3 meters is set, and the gauze has three layers.

Red-headed flies were selected as breeding varieties. Red-headed flies are common in farm toilets, with red heads and bright green backs. They are called "red-headed flies" because their heads are red.

Feeding methods of adult flies:

Feeding cage: The cage frame is 50×50×50 cm in size, and a layer of gauze of the same size is tied on it. The center of one end of the gauze is a cloth cover with a diameter of about 20 cm and a length of 33 cm, so as to take and put flies and change food.

A feeding tray (7-9 cm in diameter) is filled with sugar for adult flies to eat, or a piece of foamed plastic soaked with water is put in it to provide water for adult flies, or it can be used to lure eggs.

Adult flies are cultured in 8000 ~ 10000 per cage. Whether it is newly collected adult flies or adult flies after eclosion, sugar and water should be supplemented in time to prevent starvation. Adult flies lay eggs 3-5 times in a lifetime, up to 10 times, with 100 ~ 150 ~ 300 eggs each time.

Larvae feeding method:

First of all, the feed should be placed in a feed box, and the thickness should not exceed 4cm. Then, the trapped fly eggs (one-day-old larvae) should be slowly placed on the feed of the feeding box with an insect shovel, so that the young maggots can slowly spread out and get into the feed. When larvae eat feed, they usually climb out from top to bottom, such as high humidity, high temperature, insufficient feed and excessive population density in the box. , breeders should check at any time and take timely measures, such as.