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.
Life History In biology, flies are typical "completely abnormal insects". 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:
1, egg: the egg is milky white, banana-shaped or oval, and is 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 period was only 65438 0 days later than the normal pupa period. 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
Judging from their individuals, the smaller individuals in the group are generally male, and the larger individuals are generally male and 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 Tricholoma flies fall on flies, they will infect flies with Tricholoma 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.
The harm of flies is 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, ascaris eggs and so on. 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.
Control of flies
1. Domestic garbage should be packed in discarded plastic bags and cleaned every day to prevent flies from touching it to lay eggs.
2. When taking out the garbage, it must be put into a bucket (box, car) and stamped, and cleaned up and transported in time.
3. Eliminate garbage and sanitary corners in front of and behind residents' houses and inside and outside units.
4. Restaurants, stalls, etc. There should be facilities for preventing and killing flies, and the garbage should be put into the bucket in time and stamped.
Life span of flies A fly can live 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. If the larval stage and pupal stage are included, the life span is 25 ~ 70 days.
Feeding habits of flies flies have various feeding habits, and they all like 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.
The best way to kill flies is that flies are completely abnormal insects, and they have to go through three stages in their lives: eggs, larvae (maggots) and pupae. Therefore, the best way to kill flies is to deal with substances suitable for fly breeding. 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.
There are mice at home, and people often use rodenticide to kill them. If the annoying mice stop making trouble, they will forget to kill them. 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.
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.
Why do flies always rub the first two 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 sci-fi horror film. The sequel "Fly II" seems to tell a series of things that happened after a scientist possessed the genes of flies. I'm too lazy to find links to specific stories, so I should find a lot.
In addition, there should be an aphrodisiac also called "fly".