CATDOLL : CATDOLL: How long is the breeding cycle of flies?

Flies have the physiological characteristic of laying eggs for life after mating once. A female fly can lay eggs 5 to 6 times in her life, with about 100 to 150 eggs each time, and up to 300 eggs at most. Ten to twelve generations can be reproduced in one year.

The lifespan of a fly is about one month in midsummer, but it can be extended by 2-3 months in lower temperatures. When the temperature is below 10℃, it can hardly move and its lifespan is longer. The adult lifespan of an ordinary fly is 15-25 days. If the larval and pupal stages are included, the lifespan is 25-70 days. The main influencing factors are temperature, humidity, food and water.

Additional information:

The harm of flies

1. Flies are harmful to humans because they carry a variety of pathogenic microorganisms. Flies have hairy bodies and their foot pads can secrete mucus. They like to crawl around in human or animal feces, urine, sputum, vomit, and corpses to feed. They are very likely to be attached to a large number of pathogens, such as Vibrio cholerae, Salmonella typhi, Shigella dysenteriae, and Ascaris.

2. Flies often stay on human bodies, food, and tableware. When they land, they have the habit of rubbing their feet and brushing their bodies. The pathogens attached to their bodies will quickly contaminate food and tableware.

3. Flies have the habit of eating, vomiting and defecating at the same time. When flies eat, they first vomit out the crop fluid to dissolve the food before inhaling it. Moreover, they eat, vomit and defecate at the same time, so they vomit out the pathogens that were originally eaten into the digestive fluid, thus spreading them to humans.

Reference source: Baidu Encyclopedia - Flies

【Introduction to flies】

English name: fly

According to statistics in the late 1970s, there are more than 120,000 species of Diptera insects in 132 families worldwide, of which there are more than 34,000 species of flies in 64 families. In Fuzhou city, there are 74 species in 4 families, 38 genera, etc. The main fly species are houseflies (right picture), city flies, silkworm green flies, big-headed golden flies, etc.

Flies have the physiological characteristic of laying eggs for life after mating once. A female fly can lay eggs 5-6 times in her lifetime, with about 100-150 eggs laid each time, and up to 300 eggs at most. It can reproduce 10-12 generations in a year.

Flies feed on decaying organic matter, so they are often found in poorly sanitary environments. Flies have licking mouthparts that can contaminate food and spread diseases such as dysentery.

In the ecosystem, fly larvae play an important role as decomposers of plants and animals. Because fly adults love sweet substances, they can also replace bees in the pollination of crops and variety improvement.

In clinical medicine, live maggots can be inoculated into wounds to kill bacteria, clean wounds and promote healing.

The protein-rich fly maggots are also important bait and feed, and can be produced in factories. [Edit this section] [Life history] In biology, flies are typical "complete metamorphosis insects". Their life cycle goes through four stages: egg, larva (maggot), pupa, and adult, and the morphology of each stage is completely different. The details are as follows:

The life of a fly 1. Eggs: The eggs are milky white, banana-shaped or oval, and about 1 mm long. There are two ridges on the back of the egg shell, and the membrane between the ridges is the thinnest. The larvae drill out from here when hatching. The development time of the egg stage is 8 to 24 hours, which is related to the ambient temperature and humidity. The eggs will not develop below 13°C, and will die below 8°C or above 42°C. Within the following range, the incubation time of the eggs shortens with the increase of temperature: 20 hours at 22°C; 16 to 18 hours at 25°C; 14 hours at 28°C; and only 8 to 10 hours at 35°C. The humidity of the growth medium also affects the hatching rate of the eggs: the hatching rate is highest when the relative humidity is 75% to 80%; the hatching rate is significantly reduced when it is below 65% or above 85%.

2. Larvae: The larvae of flies are commonly known as maggots, and there are three stages: the first-stage larvae are 1 to 3 mm long, with only the posterior spiracles. After molting, they become the second-stage larvae, 3 to 5 mm long, with anterior spiracles and 2-cleft posterior spiracles. After molting again, they become the third-stage larvae, 5 to 13 mm long, with 3-cleft posterior spiracles. The body color of maggots changes from transparent and milky white to milky yellow from the first to the third stage until they mature and pupate. The third-stage larvae are oblong cones, with a pointed front end and a truncated rear end, without eyes or feet. The life characteristics of maggots are that they like to drill holes, fear strong light, and live in dark places where they breed all day long. They are polyphagous, and all kinds of corrupt and fermented organic matter are their delicious food. The larval stage is a critical period in the life of flies. The quality of their growth and development is directly related to the individual size and reproductive efficiency of the fly.

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

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

② Humidity: The suitable humidity for 1st to 2nd instar maggots is 61% to 80%, and the best humidity is 71% to 80%. The suitable humidity for 3rd instar maggots is 61% to 70%, and they cannot develop normally if it exceeds 80%. It can be seen that the development of maggots requires a certain humidity, but the higher the better. In production practice, the suitable humidity is 65% to 70%; below 40%, the development of maggots stagnates, pupation is extremely rare, and even leads to the death of maggots.

③ Food: One of the important ecological features of fly maggots is that they are omnivorous and they feed locally in their habitats. Someone once found as many as 76,400 fly maggots and pupae in 1.5 square meters of pig manure! Animal feed, plant feed and even protein in microorganisms are all nutrients that fly maggots like to consume. The quantity, quality, fermentation temperature and even water content of food are directly related to the development effect of fly maggots. After the third-instar fly maggots mature, they stop eating. Under low temperature of 15-20℃ and low humidity, they often leave the breeding place and drill into the nearby loose soil to pupate. Someone once found thousands of housefly pupae in the cracks of the damaged cement floor at the base of the wall in a winery.

4. Ventilation: Air circulation is conducive to the growth and development of maggots. In garbage dumps, maggots are often distributed in corners and bases with large gaps.

Mastering the growth characteristics of the above-mentioned fly maggots and using them to guide actual production will be of great benefit to improving the efficiency of fly maggot farming.

��3. Pupa: Pupa is the third metamorphosis in the life history of flies. It is barrel-shaped, i.e., the peri-pupa. Its body color changes from light to dark, and finally turns into chestnut brown, 5 to 8 mm long. Metamorphosis continues inside the pupa shell. Once the prototype of the fly is formed, it enters the eclosion stage. During eclosion, the fly relies on the alternating expansion and contraction of the frontal sac on its head to push open the head end of the pupa shell and crawl out, passing through loose sand or other culture materials to reach the ground surface. From pupation to eclosion is called the pupal stage.

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

��① Temperature: After the third-instar flies mature, they tend to pupate in a slightly lower temperature environment. However, when the temperature is below 12°C, the pupae stop developing; when the temperature is above 45°C, the pupae will die. Within the appropriate range, as the temperature rises, the pupal period shortens accordingly. At 16°C, it takes 17 to 19 days; at 20°C, it takes 10 to 11 days; at 25°C, it takes 6 to 7 days; at 30°C, it takes 4 to 5 days; at 35°C, it only takes 3 to 4 days, which is the optimal development temperature. The characteristic of pupae is that they are relatively cold-resistant. According to experiments, housefly pupae were refrigerated in a refrigerator at a temperature of 1°C and an ambient humidity of 85% for 4 days and then returned to normal room temperature. The emergence period was only one day later than the normal pupal period; Refrigeration for 3 days in the above environment did not reduce its emergence rate.

② Humidity: According to experiments, the best culture medium humidity for pupae development is 45% to 55%. Higher than 70% or lower than 15% will significantly affect the normal emergence of pupae. If pupae are soaked in water, the longer the time, the lower the pupation rate of fly maggots, and the emergence rate of pupae also decreases. Someone once fished out 1,000 fly pupae from liquid garbage, and after transferring them to a dry environment, none of them emerged as adult flies.

It is worth mentioning that if the nutrients for cultivating fly maggots are insufficient, the fly maggots will pupate without fully developing. Such pupae can also hatch into adult flies, but more than 95% of these adult flies are males, which only eat food and do not lay eggs. They will all die in about a week. Therefore, the fly maggots used for pupation must be raised with sufficient nutrients to make them fatter, and the proportion of females will be greater. Only when there are more female breeding flies can the egg-laying capacity be guaranteed and the yield be stable.

� 4. Adult flies: Adult flies that have emerged from pupae need to go through several stages of resting, crawling, stretching, spreading wings, and hardening of the body wall before they can develop into adult flies that have the ability to fly, feed, and reproduce. The body wall of a housefly that has just emerged from a pupa is soft and light gray, with its wings not yet spread and its frontal sac not retracted. Later, the wings will be extended, the epidermis will harden and the color will deepen, and after 1 to 1.5 hours, the wings will be able to fly. Under the condition of 27℃, adult flies will start to move and feed 2 to 24 hours after emergence. Its ecological habits are as follows.

� (1) Diet and lifespan

The feeding habits of flies depend on their species. Some specialize in sucking nectar and plant juices, while others specialize in eating human and animal blood or blood from animal wounds and secretions from the eyes and nose. The common houseflies, golden flies, silky green flies, blowflies, and flesh flies are omnivorous flies, which means they widely feed on human food, livestock and poultry secretions and excrement, kitchen scraps, and organic matter in garbage. They have a strong tendency to sugar, vinegar, ammonia, and fishy smells. According to research, if female flies are simply supplied with water, sugar, and carbohydrates, they can grow, but their ovaries cannot develop and they cannot lay eggs; only by adding protein food or multiple amino acids can they lay eggs normally. If royal jelly is used to feed female houseflies, the pre-oviposition period can be shortened and the egg-laying amount can be increased.

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

Female flies live longer than male flies, with a lifespan of 30 to 60 days; under laboratory conditions, it can be as long as 112 days. In low-temperature wintering conditions, flies can live for half a year.

Flies have a very strong ability to breed and adapt. The breeding materials of flies can be roughly divided into human feces, animal feces, decaying animals, decaying plants, garbage, and sewage. Fly maggots have a strong ability to adapt and can breed in almost all of the above six types. They especially like to live in animal feces and fermenting plants, and secondly, they like to breed in human feces and decaying animals.

⑵Activities and habitats

Flies are insects that are active during the day and have a strong tendency to move toward light. They stay still at night. The places where they move and live depend on the species, season, temperature and region. In some seasons, stable flies, summer flies and market flies may also invade homes. The big-headed golden flies, silk-light green flies, blow flies, trap flies and flesh flies mainly move and live outdoors.

The activity of flies is greatly affected by temperature. They can only crawl at 4-7℃, fly at 10-15℃, eat, mate and lay eggs at above 20℃, are particularly active at 30-35℃, stop moving due to overheating at 35-40℃, and die at 45-47℃.

Flies are good at flying. They can fly at a speed of 6 to 8 kilometers per hour, and can fly up to 8 to 18 kilometers per day and night. However, they usually move within a radius of 100 to 200 meters from their breeding grounds, and most of them do not exceed 1 to 2 kilometers.

The overwintering methods of flies are quite complicated. They can overwinter in the pupal state, as maggots, or as adults. In the northern cold and temperate zones, active houseflies are not seen in nature, but adult flies are still active in artificially heated rooms. Vegetable greenhouses often become the source of a large number of fly breeding in the spring of the following year. In the south of the Yangtze River and parts of North China, the average winter temperature is below 0 ℃, and flies can cleverly overwinter in the pupal state. In a few areas, dormant female flies and maggots covered with livestock and poultry manure can also be found. In the subtropical areas of South China, the average temperature is above 5 ℃, and flies do not hibernate and can continue to breed.

��⑶Male and female

��⒈ Look at their individuals: smaller individuals in the group are generally males, and larger individuals are generally females; ⒉ Look at their bellies to distinguish between males and females: the male fly's belly is small and flat, while the female fly's belly is large and round; ⒊ Look at their butts to distinguish between females: the male fly's butt is round, while the female fly's butt is pointed.

�⑷Mating and reproduction

��Under suitable temperature, male houseflies can reach sexual maturity and mate 18 to 24 hours after emergence and female houseflies can reach sexual maturity and mate 30 hours after emergence. Mating usually takes place between 5:00 and 7:00 in the morning. Sensitive sense of smell, sex pheromones and vision are all important factors that promote mating between male and female flies. A mating pair of houseflies can stay in one place for a long time, crawling together, flying together, and the effective mating time can last up to 1 hour. Most houseflies only mate once in their lifetime. The semen of male flies can be stored in the spermatheca of female flies for a long time, stimulating egg laying, and the eggs can be continuously fertilized for 2 to 3 weeks without mating with another male fly. This is rare in other insects. This is the important reason why flies have strong fertility.

The peak period of egg-laying is from 17:00 to 19:00 every day. The length of the pre-oviposition period of female flies (i.e. the time from emergence to the first egg-laying) is closely related to the ambient temperature: an average of 9 days at 15°C, only 1.8 days at 35°C, and no eggs can be laid at temperatures below 15°C. After mating, female flies often crawl into breeding crevices such as human and animal feces, extend their ovipositors and lay eggs deep inside the breeding organisms to ensure that the eggs are fully protected.

Flies have amazing fertility. It has been observed that houseflies in the laboratory lay about 100 eggs per batch, and one female fly can lay 10-20 batches of eggs, with a total of 600-1000 eggs. In nature, each female fly can lay 4-6 batches of eggs in its lifetime, with an interval of 3-4 days between each batch, and each batch of about 100 eggs, with a lifetime egg production of 400-600 eggs. 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 generations to reproduce a total of 200 trillion flies!

5. Natural enemies

Although flies have strong reproductive capacity and a prosperous family, 50% to 60% of their offspring die prematurely due to natural enemy attacks and other disasters. There are three types of natural enemies of flies: the first is predatory natural enemies, including frogs, dragonflies, spiders, mantises, ants, lizards, geckos, robber flies and birds. Chicken manure is the breeding ground of houseflies and stable flies, but there are often ferocious giant chelicerae and earwigs in it, which will prey on fly eggs and maggots in feces. The second is parasitic natural enemies, such as parasitic wasps such as ichneumon wasps and small wasps, which often lay their eggs in fly maggots or pupae, and eat fly maggots and fly pupae after hatching. Some people have found that among the flesh fly pupae dug out in spring, 60.4% were attacked by parasitic wasps and died prematurely. The third is microbial natural enemies. Japanese scholars have found that Bacillus Morita can inhibit the breeding of flies, and Chinese scholars have also found that if the spores of "Fly Monophyll Fungus" fall on flies, they will be infected with Monophyll Fungus. All of these are worthy of attention for fly maggot breeders.

The use of cages to breed flies in ordinary houses is a technology commonly used in fly farms that have emerged in China in recent years. This technology requires the installation of heating facilities in the room. Otherwise, when the indoor temperature does not reach 27°C in autumn, winter and spring, the reproductive capacity of flies will seriously decline. When the room heating temperature is low, especially in the north, in winter, the method of making flies pupate to keep them alive has to be adopted, which causes the fly breeding to be interrupted and the economic benefits to decline sharply. Breeding flies in plastic greenhouses has successfully solved this problem. It can make flies produce continuously all year round, and increase the breeding benefits several times, becoming a very promising technology.

Flies have the following requirements in terms of temperature, humidity and light:

The most suitable temperature for flies is 27℃～30℃. At 8～12℃, flies can move, but cannot mate or stand on food. They can only land on the ceiling and walls and do not like to move. At minus 5℃, they die in 3～5 days. Fly larvae require a higher temperature than adults. The most suitable temperature for their fastest development is 35℃. They stop moving at minus 1～2℃ and die at minus 5～6℃. When the temperature is too high at 45～55℃, their growth rate is reduced by half compared with normal temperature. Fly larvae require a food temperature of 30～35℃. In terms of humidity, adults require an indoor humidity of 55%～60%. When the humidity is too high, the legs and body of the flies are easily wet and hinder their activities. The humidity required during the growth period of larvae is 65%～70%. Flies like to move in bright places. The brighter the brightness, the greater their activity. Artificially bred flies should have lighting devices in the room, and the light should be on for more than 10 hours a day. [Edit this paragraph] [Harm of flies] Flies are harmful to humans because they carry a variety of pathogenic microorganisms. Flies have hairy bodies and their foot pads can secrete mucus. They like to crawl and feed on human or animal feces, urine, sputum, vomitus, and corpses. They are very likely to attach a large number of pathogens, such as Vibrio cholerae, Salmonella typhi, Salmonella dysenteriae, Salmonella hepatitis, poliomyelitis bacteria, hepatitis A bacteria, hepatitis B bacteria, and roundworm eggs. They often stay on human bodies, food, and tableware. When they stop, they have the habit of rubbing their feet and brushing their bodies. The pathogens attached to them quickly contaminate food and tableware. When flies eat, they first spit out the crop fluid to dissolve the food before inhaling it. They eat, spit, and defecate at the same time. In this way, they also spit out the pathogens that were originally eaten into the digestive fluid, contaminating the food they have eaten. If people eat these foods or use contaminated tableware again, they will get sick. The spread of cholera, dysentery and bacterial food poisoning is directly related to the spread of flies, but it is not completely useless. Without it, humans will be trapped in a rotten place. [Edit this paragraph] [Fly prevention and control] 1. Pack domestic garbage in plastic bags and clear it every day. Do not stay in one place for a long time to prevent flies from contacting and laying eggs.

2. Trash bins (boxes, carts) must be covered and removed in a timely manner.

3. Timely eliminate garbage and sanitary dead corners in front of and behind houses, inside and outside units.

4. Restaurants, stalls and places where food is available should have fly prevention and fly killing facilities.

5. Residents in urban areas are prohibited from raising poultry and livestock.

6. Do not use chicken, duck or fish viscera or bones as flower fertilizer.

7. Hotels, restaurants and bars must have complete fly prevention and control facilities, and garbage must be sealed and removed in a timely manner.

8. You can use natural enemies for prevention and control. For example: spiders, geckos, etc. [Edit this section] Five ways to repel flies 1. Vinegar repellent method

Spray some pure vinegar indoors and flies will stay away.

2. Orange peel fly repellent method

Lighting dry orange peels indoors can not only repel flies but also eliminate indoor odors.

3. Onion fly repellent method

Put more chopped onions, shallots, garlic, etc. in the kitchen. These foods have strong spicy and irritating smells that can repel flies.

4. Tomato fly repellent method

Placing a pot of tomatoes indoors can repel flies.

5. Use tea residue to repel flies

Dry the remaining tea leaves and burn them near toilets or stinky ditches. This will not only repel mosquitoes and flies, but also remove odors. [Edit this paragraph] [The "8864 Ways" of Human Fly Killing] 1. The most primitive: swatting flies to death with a fly swatter. The effectiveness of this method of killing flies depends largely on the skills of the operator. Advantages: low cost. Disadvantages: The effectiveness of killing flies depends largely on the skills of the fly killer; it will cause pollution. Recently, electronic fly swatters have appeared, which overcome the disadvantage of traditional fly swatters that they will cause pollution, but the cost of killing flies has increased.

Second, the fastest: insecticides to kill flies. Currently, there are two types of fly killers on the market: stomach poisons and contact killers. ① Stomach poisons. They enter the insect's digestive system through the insect's mouth to kill the insect, such as trichlorfon. ② Contact killers. They penetrate into the insect's body after contacting the epidermis or appendages, or corrode the wax layer of the insect's body, or block the valve to kill the pest, such as pyrethroids, mineral oil emulsions, etc. Killing flies will pollute the environment, especially stomach poisons, which are not suitable for food factories with food production and pharmaceutical factories with drug production.

3. Kill flies with UV lamps day and night. Flies are phototactic animals, especially sensitive to UV rays. Using this characteristic, humans invented UV lamps. The electric grid outside the UV lamp can electrocute flies to death. Advantages: No pollution; flies can be killed day and night. Disadvantages: Sparks will be generated, not suitable for flammable and explosive places.

Fourth, the safest method: Place fly paper. When flies accidentally hit or land to rest, they will be stuck and unable to move. This method is only suitable for places where there are many flies and strict fly control is not required.

5. Everything should be left to nothing - "fortify the walls and clear the 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, store all food properly and dispose of garbage properly, which is a fatal blow to flies.

6. The trump card - killing flies with a wet rag. When a wet rag is thrown, it has greater kinetic energy, so the range is longer. In addition, the rag covers a large area, which increases the hit rate. After a period of practice, the rag thrown by the practitioner will become a nightmare for flies. [Edit this paragraph] [Lifespan of flies] A fly can live for about 1 month in midsummer. But in low temperatures, its lifespan can be extended by 2 to 3 months. When it is below 10 degrees, it can hardly move and its lifespan is longer. The lifespan of an ordinary adult fly is 15 to 25 days. If its larval and pupal stages are included, its lifespan is 25 to 70 days.