A maggot is the larva of a fly (order Diptera); it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, and blowflies, [1] rather than larvae of the Nematocera, such as mosquitoes and crane flies.
A maggot is the larva of a fly (order Diptera); it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, and blowflies, [1] rather than larvae of the Nematocera, such as mosquitoes and crane flies.
"Maggot" is not a technical term and should not be taken as such; in many standard textbooks of entomology, it does not appear in the index at all. [2] [3] In many non-technical texts, the term is used for insect larvae in general. Other sources have coined their own definitions; for example: "The term applies to a grub when all trace of limbs has disappeared" [4] and "Applied to the footless larvae of Diptera". [5] Additionally, in Flies: The Natural History and Diversity of Diptera, the author claims maggots "are larvae of higher Brachycera (Cyclorrhapha)." [6]
Maggot-like fly larvae are of significance in ecology and medicine; among other roles, various species are prominent in recycling carrion and garbage, attacking crops and foodstuffs, spreading microbial infections, and causing myiasis. Maggots are also particularly important in forensic entomology because their development can help determine the time of death, particularly maggots in the Calliphoridae family. [7]
Anglers use maggots usually commercially supplied to catch non-predatory fish. Maggots are the most popular bait for anglers in Europe. [8] Anglers throw handfuls into the "swim" they are targeting, attracting the fish to the area. The anglers then use the largest or most attractive maggots on the hook, hoping to be irresistible to the fish. Commercial maggot breeders from the UK sell their maggots to tackle dealers throughout the E.U. and North America.
In North America, maggots have been used primarily as ice fishing bait; recently, however, anglers have started using them year-round.[ citation needed ] Artificial maggots for fishing, either in natural or fluorescent colors, have been developed and are used for trout, panfish, or salmon species. [9]
Live maggots of certain species of flies have been used since antiquity for wound debridement. Larvae of calliphorid flies of the species Lucilia sericata are widely used. [10] Not all species are safe and effective; use of the wrong species would invite pathological myiasis. [11]
In controlled and sterile settings overseen by medical practitioners, maggot therapy introduces live, disinfected maggots into non-healing skin or soft wounds of a human or animal. They feed on the dead or necrotic tissue, leaving sound tissue largely unharmed. Studies have also shown that maggots kill bacteria. Three midgut lysozymes of L. sericata have antibacterial effects in maggot debridement therapy. The study demonstrated that the majority of gram-positive bacteria were destroyed in vivo within the particular section of the L. sericata midgut where lysozymes are produced. During the passage through the intestine of the maggots, the ability of bacteria to survive drastically decreased, implying the antibacterial action of the three midgut lysozymes. [12] In 2005 maggot therapy was being used in about 1,300 medical centers. [13]
Acceptance by healthcare workers has inhibited acceptance, but a supplier of maggots said in 2022 that she had noticed significantly more acceptance over the four years she had worked in the field. Acceptance among patients is high. [14]
The presence and development of maggots on a corpse are useful in the estimation of time elapsed since death. Depending on the species and the conditions, maggots may be observed on a body within 24 hours. The eggs are laid directly on the food source, and when the eggs hatch, the maggots move towards their preferred conditions and begin to feed. By studying the insects present at a crime scene, forensic entomologists can determine the approximate time of death. Insects are usually useful after a post-mortem interval (PMI) of approximately 25–80 hours, depending on ambient conditions. After this interval, this method becomes less reliable. Blow flies are often used in forensic entomology to determine PMI because of their oviposition on carrion and corpses. The black blowfly, Phormia regina (P. regina), is extremely widespread across the US and often the earliest species to oviposit on a corpse, making it especially important to forensic science. [15]
Maggots are useful as well in entomotoxicology, in determining the presence of drugs in a corpse's system. Maggots bioaccumulate xenobiotics (substances, drugs, metals, etc.) from tissue and bone, therefore allowing entomologists to determine if xenobiotics, most commonly drugs, were present in the body before death. [16] This is useful in concluding a cause of death in many different cases including overdoses and poisonings. It also helps in determining manner of death including suicide or homicides. [17] Maggots are able to bioaccumulate substances from fresh corpses, as well as fully decomposed skeletonized bodies. [18] Data and resources on entomotoxicology are sparse as it is a relatively new field of study. [19] The knowledge of how the drug or substance effects the development of maggots is necessary as some drugs such as cocaine and methamphetamine are proven to accelerate the development of larvae, whereas opiates are shown to decelerate said rate. [20]
As with fleas and ticks, maggots can be a threat to household pets and livestock, especially sheep. Flies reproduce rapidly in the summer months, and maggots can come in large numbers, creating a maggot infestation and a high risk of myiasis (a maggot infestation of living tissue) in sheep and other animals. Humans are not immune to the feeding habits of maggots and can also contract myiasis. Interaction between humans and maggots usually occurs near garbage cans, dead animals, rotten food and other breeding grounds for maggots.
When maggots turn into adult flies and start the life cycle over, numbers will grow exponentially if unchecked, but disease, natural predators and parasites keep the population under control. Sealing garbage and using a garbage disposal or freezing rotting leftovers until waste collection day helps prevent infestation. Introducing an environmental control, such as Hister beetles, can also help reduce maggot populations.
Forensic entomology is the scientific study of the colonization of a dead body by arthropods. This includes the study of insect types commonly associated with cadavers, their respective life cycles, their ecological presences in a given environment, as well as the changes in insect assemblage with the progression of decomposition. Insect succession patterns are identified based on the time a given species of insect spends in a given developmental stage, and how many generations have been produced since the insects introduction to a given food source. Insect development alongside environmental data such as temperature and vapor density, can be used to estimate the time since death, due to the fact that flying insects are attracted to a body immediately after death. The identification of postmortem interval to aid in death investigations is the primary scope of this scientific field. However, forensic entomology is not limited to homicides, it has also been used in cases of neglect and abuse, in toxicology contexts to detect the presence of drugs, and in dry shelf food contamination incidents. Equally, insect assemblages present on a body, can be used to approximate a given location, as certain insects may be unique to certain areas. Therefore, forensic entomology can be divided into three subfields: urban, stored-product and medico-legal/medico-criminal entomology.
The Calliphoridae are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing bait, are known as gentles. The family is known to be polyphyletic, but much remains disputed regarding proper treatment of the constituent taxa, some of which are occasionally accorded family status.
Myiasis, also known as flystrike or fly strike, is the parasitic infestation of the body of a live animal by fly larvae (maggots) that grow inside the host while feeding on its tissue. Although flies are most commonly attracted to open wounds and urine- or feces-soaked fur, some species can create an infestation even on unbroken skin and have been known to use moist soil and non-myiatic flies as vector agents for their parasitic larvae.
The common green bottle fly is a blowfly found in most areas of the world and is the most well-known of the numerous green bottle fly species. Its body is 10–14 mm (0.39–0.55 in) in length – slightly larger than a house fly – and has brilliant, metallic, blue-green or golden coloration with black markings. It has short, sparse, black bristles (setae) and three cross-grooves on the thorax. The wings are clear with light brown veins, and the legs and antennae are black. The larvae of the fly may be used for maggot therapy, are commonly used in forensic entomology, and can be the cause of myiasis in livestock and pets. The common green bottle fly emerges in the spring for mating.
Maggot therapy is a type of biotherapy involving the introduction of live, disinfected maggots into non-healing skin and soft-tissue wounds of a human or other animal for the purpose of cleaning out the necrotic (dead) tissue within a wound (debridement), and disinfection.
Chrysomya is an Old World blow fly genus of the family Calliphoridae. The genus Chrysomya contains a number of species including Chrysomya rufifacies and Chrysomya megacephala. The term “Old World blow fly” is a derivative of both the associated family, Calliphoridae, and the belief that the genus Chrysomya originated in Asia and migrated to North America only relatively recently. Chrysomya’s primary importance to the field of medico-criminal forensic entomology is due to the genus’ reliable life cycle, allowing investigators to accurately develop a postmortem interval. Chrysomya adults are typically metallic colored with thick setae on the meron and plumose arista. The name comes from the word chrysos, meaning “golden” in reference to the metallic sheen of the genus’ species, and -mya, a derivation from the word myia, meaning “fly”.
Cochliomyia is a genus in the family Calliphoridae, known as blowflies, in the order Diptera. Cochliomyia is commonly referred to as the New World screwworm flies, as distinct from Old World screwworm flies. Four species are in this genus: C. macellaria, C. hominivorax, C. aldrichi, and C. minima. C. hominivorax is known as the primary screwworm because its larvae produce myiasis and feed on living tissue. This feeding causes deep, pocket-like lesions in the skin, which can be very damaging to the animal host. C. macellaria is known as the secondary screwworm because its larvae produce myiasis, but feed only on necrotic tissue. Both C. hominivorax and C. macellaria thrive in warm, tropical areas.
Chrysomya rufifacies is a species belonging to the blow fly family, Calliphoridae, and is most significant in the field of forensic entomology due to its use in establishing or altering post mortem intervals. The common name for the species is the hairy maggot blow fly, and it belongs to the genus Chrysomya, which is commonly referred to as the Old World screwworms. This genus includes other species such as Chrysomya putoria and Chrysomya bezziana, which are agents of myiasis. C. rufifacies prefers very warm weather and has a relatively short lifecycle. It is widely distributed geographically and prefers to colonize large carcasses over small ones. The species commonly has a greenish metallic appearance and is important medically, economically, and forensically.
Lucilia illustris is a member of the fly family Calliphoridae, commonly known as a blow fly. Along with several other species, L. illustris is commonly referred to as a green bottle fly. Lucilia illustris is typically 6–9 mm in length and has a metallic blue-green thorax. The larvae develop in three instars, each with unique developmental properties. The adult fly typically will feed on flowers, but the females need some sort of carrion protein in order to breed and lay eggs.
Entomological evidence is legal evidence in the form of insects or related artifacts and is a field of study in forensic entomology. Such evidence is used particularly in medicolegal and medicocriminal applications due to the consistency of insects and arthropods in detecting decomposition quickly. Insect evidence is customarily used to determine post-mortem interval (PMI) but can also be used as evidence of neglect or abuse. It can indicate how long a person was abused/neglected as well as provide important insights into the amount of bodily care given to the neglected or abused person.
In forensic entomology, entomotoxicology is the analysis of toxins in arthropods that feed on carrion. Using arthropods in a corpse or at a crime scene, investigators can determine whether toxins were present in a body at the time of death. This technique is a major advance in forensics; previously, such determinations were impossible in the case of severely decomposed bodies devoid of intoxicated tissue and bodily fluids. Ongoing research into the effects of toxins on arthropod development has also allowed better estimations of postmortem intervals.
Chrysomya bezziana, also known as the Old World screwworm fly or screwworm, is an obligate parasite of mammals. Obligate parasitic flies require a host to complete their development. Named to honor the Italian entomologist Mario Bezzi, this fly is widely distributed in Asia, tropical Africa, India, and Papua New Guinea. The adult can be identified as metallic green or blue with a yellow face and the larvae are smooth, lacking any obvious body processes except on the last segment.
Sarcophaga pernix, also known as the red-tailed flesh fly, is a fly in the Sarcophagidae family. This fly often breeds in carrion and feces, making it a possible vector for disease. The larvae of this species can cause myiasis, as well as accidental myiasis. It is potentially useful in forensic entomology.
Lucilia thatuna belongs to the family Calliphoridae, the species most commonly referred to as the blowflies, and the genus Lucilia. Along with several other species of Lucilia, L. thatuna is commonly referred to as a green bottle fly. L. thatuna is very scarce and not much is known about this particular fly. It has been noted to reside in mountainous regions of the northwestern United States.
Lucilia cuprina, formerly named Phaenicia cuprina, the Australian sheep blowfly is a blow fly in the family Calliphoridae. It causes the condition known as "sheep strike"'. The female fly locates a sheep with ideal conditions, such as an open wound or a build-up of faeces or urine in the wool, in which she lays her eggs. The emerging larvae cause large lesions on the sheep, which may prove to be fatal.
Cynomya cadaverina, also known as the shiny blue bottle fly, is a member of the family Calliphoridae, which includes blow flies as well as bottle flies. In recent years, this family has become a forensically important facet in many medicocriminal investigations in the growing field of forensic entomology. C. cadaverina is specifically important in determining a post-mortem interval, as well as other important factors.
Calliphora livida is a member of the family Calliphoridae, the blow flies. This large family includes the genus Calliphora, the "blue bottle flies". This genus is important in the field of forensic entomology because of its value in post-mortem interval estimation.
Lucilia coeruleiviridis, formerly Phaenecia coeruleiviridis, is commonly known as a green bottle fly, because of its metallic blue-green thorax and abdomen. L. coeruleiviridis was first discovered by French entomologist Pierre-Justin-Marie Macquart in 1855. It belongs to the family Calliphoridae and is one of many forensically important Diptera, as it is often found on decaying substances. L. coeruleiviridis is one of the most ubiquitous blow fly species in the southeastern United States, particularly in the spring and fall months.
Protophormia terraenovae is commonly called northern blowfly, blue-bottle fly or blue-assed fly. It is distinguished by its deep blue coloration and large size and is an important species throughout the Northern Hemisphere. This fly is notable for its economic effect as a myiasis pest of livestock and its antibiotic benefits in maggot therapy. Also of interest is P. terraenovae’s importance in forensic investigations: because of their temperature-dependent development and their prominent presence on corpses, the larvae of this species are useful in minimum post-mortem interval (mPMI) determination.
Calliphora stygia, commonly known as the brown blowfly, or rango tumaro in Māori, is a species of blow-fly that is found in Australia and New Zealand. The brown blowfly has a grey thorax and yellow-brown abdomen.
