CATDOLL : CATDOLL: Why are the maggots from chicken manure so small?

1. Why are the maggots raised by chicken manure so small?

The reason why fly maggots are small is because of the pH of chicken manure. You can try to raise them by mixing chicken manure and pig manure in a ratio of 1:1, or measure the pH of chicken manure and adjust it before trying again. Another reason is that the flies that are artificially bred are engineered flies, and the fly maggots are small, unlike the large fly maggots produced by red-headed flies and green-headed flies in the wild.

2. An incident in which the police solved a case

In a remote place in Tennessee, USA, a burnt car lies quietly, and inside the car is a charred body that has been completely disfigured. At first glance, it seems that a car accident has occurred here, the car crashed and caught fire, and the driver was burned to death. However, when the careful forensic doctor Bass dissected the charred body, he found maggots in the head of the body that were burned to death by the high temperature generated by the burning car, indicating that the maggots occurred before the burning of the car. There is no doubt that this is a murder case in which the body was moved, and the criminal tried to burn the car and the body to cover up the evidence. Bass also found live maggots on the body, which were obviously newly grown after the body was moved and the car accident was disguised. After analyzing the dead and live maggots on the body, Bass, a forensic doctor who has studied flies, concluded that the victim was killed 18 days ago. After solving the case, it was confirmed that this conclusion was completely correct. This is a typical example of using the emerging forensic entomology to assist in solving a case.

Reiter, a famous forensic doctor in Vienna, pointed out that flies can smell the stench of corpses from two kilometers away and chase them. They will also lay eggs and hatch maggots. From the hatching of eggs and the various stages of maggot growth, the time of death can be calculated. Banner Glembor, an entomologist at Illinois State University in the United States, assisted the police in solving several major cases in succession. He used the characteristics of flies, such as the big green-headed flies that are most interested in fresh corpses. Usually, they always fly in the air, first appear in the corpse, and lay eggs on the corpse. The eggs turn into maggots, and the maggots turn into pupae, and finally into flies. According to this evolution law, the error of the crime time calculated can be shortened to no more than two days. Based on these clues, the police successfully captured the murderer.

There are many examples of using flies to solve crimes. There was such a case in Hungary: one day, a boatman returned to his boat at 18:00, and a few hours later he found a postman who had been hacked to death on the boat. As the boatman was on the boat when the postman was killed, he was immediately arrested and sentenced to life imprisonment. During the autopsy, the forensic doctor truthfully recorded that many light yellow fly eggs and newly hatched maggots were found on the body. Unfortunately, the forensic doctor who lacked knowledge of the living habits and growth patterns of flies at that time did not notice this important discovery. It was not until 8 years later that the record of the presence of fly eggs and maggots on the body at that time finally cleared the boatman of the crime and he was acquitted. The reason was quite accurate: because the flies found on the body never look for the body and lay eggs in the dark, even in a warm place, it will take 10 to 16 hours for the fly eggs to hatch into maggots. The boatman returned to the boat at 18:00 that day, and it was already dark. It was impossible for the flies on the corpse to fly to the corpse and lay eggs on the day the corpse was found, and then immediately hatch maggots. This shows that the boatman was not at the scene when the incident occurred.

There are tens of millions of species of flies, and forensic doctors can sometimes prove the location of a crime based on the species of flies. Russian police found a half-rotten body in a seawater storage tank. The on-site investigation did not find any traces, but they found living maggots on the body. Because this type of maggot cannot survive in seawater, they concluded that it was a case of moving the body, and the body was moved not long ago. Based on the growth pattern of this type of maggot, they inferred that the crime was committed two weeks ago. After the case was solved, the murderer's confession was completely consistent with the judgment.

3. The relationship between flies and diseases

In addition to harassing people, contaminating food and sucking blood through their stings, flies also spread a variety of diseases and cause myiasis.

1. Disease transmission: Flies transmit diseases in two ways: mechanical transmission and biological transmission.

⑴ Mechanical transmission: Non-blood-sucking flies spread pathogens by carrying pathogens inside and outside the body and by their unique feeding habits. Flies can spread dysentery, cholera, typhoid, paratyphoid, poliomyelitis, hepatitis, intestinal protozoan diseases, intestinal helminthiasis, tuberculosis, bacterial dermatitis, yaws, trachoma and conjunctivitis, etc. Blood-sucking flies can experimentally spread poliomyelitis, anthrax, spirochetosis and cutaneous leishmaniasis, etc.

⑵ Biological transmission: Glossina (tsetse fly) can transmit human trypanosomiasis (sleeping sickness), the pathogens of which are Trypanosoma brucei Gambiae and Trypanosoma brucei Rhodesiense, which are prevalent in Africa. In addition, Amiota okadai is the intermediate host of conjunctival sucking nematodes. 2. Myiasis is the invasion of human and vertebrate living bodies by the larvae of Diptera insects. This section is limited to flies, and can be divided into the following types according to the clinical parasitic sites:

1) Skin myiasis: The most common cases are caused by the larvae of the skin fly and the cow fly. When the female fly lays eggs on human hair or clothes, the hatched larvae drill into the skin and move under the skin. When they stay there, a boil-like mass is formed there. After a few days, they continue to migrate. This happens periodically and finally moves to the epidermis and opens a small hole. The larvae can escape from the small hole or be squeezed out by people's hands. Usually 1 to 2 people are infected. The most invaded parts are the head and chest. In some cases, the larvae can migrate to deep tissues and organs such as the chest cavity, abdominal cavity, eyes, and brain. More than 250 human cases caused by skin flies have been reported in China, most of which are first-instar larvae, and second- and third-instar larvae are rare. The first-instar larvae of the stomach fly can drill into the human skin and migrate, forming a tortuous tunnel, presenting a bloody streak-like creeping rash. The worm body can be picked out with a needle at the end of the bulge. There are more than ten cases of human skin myiasis caused by black-horned gastrodrones, red-tailed gastrodrones and intestinal gastrodrones reported in China. The larvae of the human skin fly distributed in America and the human tumor fly distributed in Africa are similar to the damage of the skin fly to humans, forming boil-like lumps at the site of the skin drilling, but they do not migrate.

2) Eye myiasis: The most common cases are caused by the first-instar larvae of the genera Myrias and Rhinopharynx. During flight, the flies directly collide with the eyes and lay their larvae on the conjunctiva and cornea, causing acute conjunctivitis or corneal ulcers. Domestic reports of human eye infections include: more than 560 cases of sheep myrias, more than 170 cases of broad-fronted myrias, and more than 20 cases of purple-nosed myrias. Occasionally, there are cases of housefly, green fly, leather fly, and cow fly larvae invading human eyes.

3) Gastrointestinal myiasis: usually caused by people accidentally eating food or drinking water contaminated by fly eggs or larvae, or flies laying eggs near the anus or larvae entering the intestines. Patients may experience nausea, vomiting, abdominal pain, diarrhea, and loss of appetite. More than 40 cases have been reported in China. The fly species include house flies, stable flies, summer toilet flies, tuberculate toilet flies, and some fly species of Sarcophagidae, Calliphoridae, and Gastromyidae.

4) Myiasis of the ear, nose, pharynx and mouth: Human infection is mainly due to the smelly secretions of the diseased organs, which can induce flies to lay eggs or larvae and cause disease. More than 20 cases have been reported in China. The pathogenic fly species include houseflies, stable flies, big-headed golden flies, silk-light green flies, copper green flies, fork-shaped flies, black-tailed black flesh flies, sharp-hook flax flies, sheep flies, black-whiskered dirt flies and maggot-infected golden flies.

5) Urogenital myiasis: People are often infected by being naked, and the odor of urethral or vaginal excrement attracts flies to lay eggs, and the hatched larvae enter the urogenital tract and cause disease. More than ten cases have been reported in China. The pathogenic fly species include housefly, summer toilet fly, toilet fly, big-headed golden fly, silk-light green fly, copper green fly and brown-tailed flesh fly.

6) Traumatic myiasis: The odor from wound bleeding and suppuration attracts flies to lay eggs or larvae, causing the disease. More than 20 cases have been reported in China. Among the fly species, the most common cases are those of the golden fly. Others include the house fly, the black-whiskered dung fly, the Chen's dung fly, the silk-bright green fly, the red-headed blowfly, and the fat-whiskered flax fly.

7) Blood-sucking fly maggots: Such as the yellow dust fly distributed in Africa, the larvae attack humans at night and suck blood.