Because flies like to eat liquid food rich in moisture.

If possible, a fly's favorite food is sugar water. Because flies have licking and sucking mouthparts, they need to spit out digestive juices from their mouths to break down food into liquid before eating it.

The main reason why we see a lot of flies eating shit is because generally there are not many flies in places with delicious food, and flies have no way to get better food, so they have to condescend to eat shit. The most important thing is--you don't have to worry about being swatted to death when eating this. ^_^

But if you put shit and watermelon rind together, flies will of course choose the watermelon rind because it is said to taste good.

Fly prevention and control

There are the most types of flies, and different types of flies appear in every season. However, the most common flies in our daily lives are small house flies, green flies, and house flies. Flies, blowflies, big-headed golden ropes and a few other species. Each type of fly has its own unique breeding ground. For example, house flies are most common in the trash cans around our lives; green flies and blowflies are most common in aquatic product stalls and fruit stalls at farmers’ markets; big-headed golden flies are often found in cesspools. See you elsewhere.

The fecundity of a fly is extremely strong. Its life cycle consists of four cycles: egg - larva (maggot) - pupa - adult fly. Except for adult flies, the other three stages develop in the breeding grounds of garbage and sewage places.

For the prevention and control of flies, the most important thing is to manage various breeding areas. First, all types of discarded garbage must be emptied in a timely manner every day. Garbage containers and garbage rooms must be flushed regularly with water to remove soil in corners to reduce the egg-laying and breeding of flies. Second, develop a good sense of hygiene, do not dump garbage or splash sewage indiscriminately, and keep the environment hygienic. Third, public places must be cleaned by dedicated personnel, and garbage from farmers’ markets and food processing must be bagged and transported. Fourth, keep sewers and chemical drains unobstructed to prevent blockage and overflow and reduce breeding grounds for flies.

Flies have a strong sense of smell and flying ability, and can fly to the dining table from thousands of miles away. Timely installation of screen doors, screen windows and wind curtains can effectively prevent flies from flying in. Fly traps and fly paper are both tools for catching adult flies and can be selected and used according to different situations.

During the peak season of flies, high-density garbage bins, garbage transfer stations and other places can be sprayed with chemicals appropriately to quickly reduce the density.

Prevention and Control of Four Pests - Flies

1. The biological status and main characteristics of flies. Flies belong to the class Insecta, subclass Pteridae, order Diptera, and are customarily collectively referred to as flies. Its body consists of three parts: head, thorax, and abdomen. The front end of the head has two large compound eyes. The unique feeding mouthparts of flies are licking and sucking mouthparts (that is, both the upper and lower jaws have degenerated, leaving only a pair of rod-shaped mandibular palps; The lip is specialized into a long beak, and the end of the beak is enlarged into a pair of labial valves with a pair of annular grooves. A sword-shaped upper lip is attached to the base of the back of the beak, and only a flat and long tongue is attached below it, and the two phases are closed to form the food canal). , suitable for licking and sucking food; its antennae are awn-like antennae (that is, the flagellum has only one section, is fat, and has an awn-like seta on it); it has only one pair of large and well-developed forewings, membranous, with simple veins , the hind wings degenerate into balance rods; the legs have 5 tarsal segments; the development process is complete metamorphosis, and the larvae are maggot-like. 2. Common fly species Common flies in my country are fly species that breed around people’s residences and are closely related to people. They are scientifically called residential fly species, including house flies, market flies, stable rot flies, etc. 18 kind. There are three main types of flies in Putian urban area: house flies (matte), golden flies (golden bodies), and green flies (greenish bodies). 3. Breeding Habits of Flies The breeding habits of flies are relatively complex, and their breeding places are quite wide. Usually, the breeding places of common residential flies are divided into places with the following five types of breeding biomass. Each type can be divided into several types, namely : 1. Human feces: divided into human cesspits (tanks), toilets (earth toilets, latrines), human excrement (urine fields), surface human excrement blocks, greening fertilization (such as flower pots, flower beds, and retting pits in nurseries), etc. type. 2. Animal dung: There are dung piles, dung tanks, dung fields, stables, single dung blocks, etc., and there are cow dung (buffalo dung, cow dung), horse dung (mule dung, donkey dung), pig dung , sheep dung, dog dung, poultry dung (chicken, duck, goose dung) and miscellaneous dung. 3. Decaying organic matter: divided into animal carcasses (dogs, cats, rats, birds, snakes, frogs, fish, shellfish, crustacean insects), carrion (poultry meat, fish meat, bird meat, poultry juice, animal skins, Animal hair, organs, etc.), as well as eggs, dairy products, pickled meats, salted fish, tanner tank sediments, etc. 4. Corrupt plant matter: divided into rotten vegetables, fruits, livestock feed (green fodder, wheat flour, bean cake, soybean meal, distiller's grains), sauce and sauce products, pickle jars, etc. 5. Garbage categories: divided into garbage bins (buckets), garbage channels, garbage rooms (buildings), small garbage sorting sites, and large garbage accumulation sites. 6. There are also types of mixed compost, feed inlets of biogas digesters, silt in underground ditches and open ditches, and swill tanks. 4. Feeding habits of flies The feeding habits of flies are very complex, and their feeding behavior is quite unique, which constitutes the main part of their hygienic significance. They are all omnivorous flies, that is, they can feed on various substances, including human food, Human and poultry secretions and excretions, kitchen waste and other garbage, as well as plant juices, etc., can all be used for it to feed on. Some species prefer plant substances, while others prefer meaty substances.

Judging from the nutrients required by adult flies, if female house flies are fed only water and sugar or other absorbable carbohydrates, although they can live well, their ovaries will not develop normally and they will not be able to lay eggs normally. Only with eggs or other proteins or 16 kinds of amino acids can the ovaries develop normally. Feeding female houseflies with royal jelly can promote the full development of the ovaries, shorten the pre-oviposition period, and increase the amount of eggs laid. The feeding behavior of house flies is very interesting. After it is full, it can defecate after a short interval (a few minutes). Because it vomits and defecates frequently and loses a lot of water, it also prompts it to take food frequently. Therefore, it eats, vomits, and poops on people's food, causing serious contamination of the food. This has certain advantages in mechanically transmitted diseases. importance. 5. The harm of flies. Flies carry countless bacteria and viruses, and can carry pathogens and spread diseases, such as bacterial diseases such as cholera, typhoid, dysentery, bacterial food poisoning, etc.; viral diseases such as poliomyelitis, viral hepatitis, Trachoma, etc.; protozoal diseases such as amoebic dysentery; parasitic diseases such as roundworm and cysticercosis. Secondly, myometosis occurs when fly larvae parasitize the living tissues or cavity of humans and animals. Harassment and blood-sucking again. There is also a kind of blood-sucking fly among flies. As the name suggests, it makes a living by harassing and sucking blood. Fortunately, it mainly attacks domestic animals and does little harm to humans. At the same time, the presence or absence of flies directly reflects the quality of environmental sanitation, which affects the development of the catering industry and tourism and the construction of a hygienic city. 6. Fly prevention and control The reproductive ability of flies is quite strong. Even in environments where natural conditions are unfavorable to it, it can reproduce 10-12 generations in a year. What is this concept? Assuming that the ratio of male to female flies is 1:1, then after 10 generations of 100 female flies, the total number will reach 2 trillion! It reminds us that in fly control work, we must first eradicate fly breeding sites, and we must start every spring when flies just start to reproduce. Otherwise, once the conditions are right, the number of flies can be quite astonishing. Work in this area also uses comprehensive remediation as a strategy, with environmental prevention and control as the main fundamental measure. By eliminating and processing fly breeding biomass (including feces, garbage, abandoned animals and plants, etc.), the number of flies is fundamentally controlled. Chemical control is also an important means of controlling flies in residential areas, especially when disasters occur, intestinal infectious diseases are prevalent, or when the house fly population density is particularly high. (1) Application of insecticides on the staying surface: Spray pesticides with residual and contact effects on the surfaces where flies have landed, on indoor walls and ceilings more than 2 meters away. Generally, surfaces with strong water absorption should be sprayed at a low concentration and a large dosage, while surfaces with poor water absorption should be sprayed with a high concentration and a low dosage. (2) Space spraying: It can kill adult flies quickly, but the effect is short-lived because adult flies must be exposed to the sprayed mist particles before they can be poisoned and die. Commercially available aerosols and sprays are generally only used for space spraying because they are expensive. When spraying, the nozzle should be pointed upward, not toward the ground. Hanging poisonous fly ropes, placing fly poisonous baits, sticky fly paper, fly traps, etc. can poison or capture adult flies. In addition to this, physical and mechanical methods can also be used. The oldest fly swatter belongs to this method, and there are many other methods, such as installing screen windows and door screens, using screen covers to prevent flies from contacting food, etc., which can also achieve certain results. It is difficult to eliminate flies, but even more difficult to consolidate. To consolidate the results of fly control, we must continue to improve basic sanitation facilities for fly control, eliminate breeding organisms in a timely manner, promptly discover and treat new breeding areas, conduct regular fly density tests, and control the density of flies at a level that is not harmful. 6. Implementation of temporary fly density testing 1. Cities with a population of less than 1 million will set up two temporary testing points, one in the city center and one on the edge of the city. One additional point should be added for every 1 million additional population, and most points should be located on the edge of the city. Each temporary testing site includes: 1 farmer's market, 5 small restaurants, and 1 green belt. 2. Clinical testing methods and tools vary from place to place. The farmer's market uses 2 round fly traps (40cm high, 25cm in diameter, 3 legs, the bait basin is 2.5cm away from the bottom of the cage; the conical core is 35cm high, and the top opening is 2cm in diameter) and 5 fly paper sheets (25×25cm ); use 2 pieces of fly paper inside the small hotel, 1 fly trap in the backyard; use 2 fly traps in the green area. 3. Conduct the test on the 4th day of every ten days, three times a month, each time from 8 a.m. to 4 or 8 a.m. of the next day. Record the number of catches, weather conditions, and the date and scope of important fly control measures.

(Author's unit: School of Bioengineering, Fujian Normal University) □Lin Yanhong

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