Cochliomyia macellaria | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Diptera |
Family: | Calliphoridae |
Genus: | Cochliomyia |
Species: | C. macellaria |
Binomial name | |
Cochliomyia macellaria (Fabricius, 1775) | |
Synonyms [1] | |
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Cochliomyia macellaria, also known as the secondary screwworm, is a species of blow fly in the family Calliphoridae. [1] [2] [3] These screwworms are referred to as "secondary" because they typically infest wounds after invasion by primary myiasis-causing flies. [1] While blow flies may be found in every terrestrial habitat, C. macellaria is primarily found in the United States, American tropics, and sometimes southern Canada. [4] They are most common in the southeastern United States in states like Florida. C. macellaria have a metallic greenish-blue thorax and a red-orange head and eyes. [5] These adult blowflies range from 5–8 mm in size. [5]
Since the fly larvae infect the wounds and dead tissue of animals, these flies pose a grave medical and economic risk to humans and livestock. C. macellaria are attracted to carrion and garbage and are often found in slaughterhouses and outdoor markets in the tropics. While these flies carry many various types of Salmonella and viruses like the swine influenza, C. macellaria can also serve as important decomposers in our ecosystem. [6]
Cochliomyia macellaria are classified as intermediate sized flies with a dull or bright metallic, blue-green coloration. On their thorax, there are three black longitudinal stripes that interrupt the blue-green color. The eye and head of these flies are orange-red in color. C. macellaria also has pale setae on the fronto-orbital plate outside of the frontal bristles. [7] On C. macellaria the frontal row of bristles extend anteriorly to the base of the first antennal segment and consist of 12–14 bristles. [8] The legs of the fly are orange brown to dark brown, and the coxae are orange brown to black with a green metallic luster. [8] C. macellaria possess a dark reddish brown anterior femur and an orange-red anterior tibia. [8] The anterior tibia also has four short bristles that are placed on the dorsal side. [8] The color of the wings of the fly is orange brown tint towards the base. On these wings, the veins in the fly are orange brown to dark brown. [8] The costal sessions 2 to 6 are in the proportions 78:56:96:30:6:6. [8] The first genital section is black with a metallic green luster. [8] On the fly, the scattered setae and a defined marginal row of bristles; the second segment is smaller with a dark brown to black tint with scattered setae. [8]
Cochliomyia macellaria is closely related to C. hominivorax but can be distinguished from C. hominivorax in three primarily ways: two of which are seen in adults and one which is seen in the larvae. In adults, the hairs on the fronto-orbital plate are black in C. hominivorax, but are pale in C. macellaria. Additionally, the central black stripe on the thorax extends only slightly in front of the mesonotal suture in C. hominivorax and well in front of the suture in C. macellaria. C. macellaria larvae, unlike like C. hominivorax larvae, do not have pigmented tracheal trunks but instead have V-shaped spines on the anal protuberance. C. macellaria also does not have an oral sclerite. [7] [9] [10]
Cochliomyia macellaria is most often found in the southeastern part of the United States, in states like Florida, Louisiana, and Georgia. [8] Despite the high concentration in these states, these flies have been found as far north as Southern Canada and as south as the Neotropics, with the exclusion of countries like Chile and Argentina. [8] While they have been found in this large expanse of areas, they have been shown to thrive most in warm and humid areas like the Southern United States, Caribbean Islands, Central America, and northern South America. [8] In these areas, the population size typically increases during periods of extended rainfall. [11]
The territories of these blowflies are relatively small, especially during the time of mating. In this period, these flies will stay within a couple meters of one another. [4]
The average life span of an adult C. macellaria is 2–6 weeks. [12] In this time period, the females try to increase the chances of producing as many surviving offspring as possible. [13] In a lifetime, C. macellaria may lay up to 1000 or more eggs. These eggs are typically laid in groups of 40 to 250. Females may also lay their eggs with other females, leading to an accumulation of thousands of eggs. [12]
The eggs of C. macellaria are laid in large groups (40–250 eggs at one time) and typically hatch in about 24 hours. [12] The time taken for eggs to hatch often depends on moisture, temperature, and precipitation. In favorable conditions, the eggs may hatch in just four hours. [12] These eggs are about 1 mm long and appear white to pearl white in color. [5]
The larval stage of C. macellaria is referred to by the common name of secondary screwworms; this is due to the presence of small spines on each body segment that resemble parts of a screw. The larval stage of C. macellaria immediately follows the egg stage and is typically broken down into three substages or instars. Upon hatching, the larve appear a cream color, have cylindrical bodies with 10 or more spines around the spiracular area, possess incomplete peritremes (an indistinct or absent button), and have bands of small spines on each segment. [9] C. macellaria, unlike like C. hominivorax, do not have pigmented tracheal trunks; instead, they have V-shaped spines on the anal protuberance. C. macellaria also does not have an oral sclerite. [7] [9] [10]
Cochliomyia macellaria larvae will feed on the decaying flesh of the animal that they have been laid on until they reach maturity. This stage of maturity is during the third instar and by this time point, the larvae may be as long as 17 mm. The entire larval stage is about four to seven days long, and afterwards, the larvae fall off the food source to pupate in the top layer of the soil. [9]
The C. macellaria larvae will typically burrow underneath the top layer of soil, leaves, garbage and begin to pupate there. [14] During this stage, the outer layer begins to turn brown from the cream white that it used to be. The outer skin will begin to shrink and harden while the pupa develops entirely in the hardened shell. [14] Based on the temperature, the length of this stage will vary greatly. In warmer temperatures, the stage may last as short as seven days, but in colder temperatures, it may last as long as two months. [14]
Adult C. macellaria are considered to be medium-sized flies because they are about 6 to 9 mm in size and appear bright metallic blue-green to blueish purple in color. [3] [8] These adults typically spend one to two days maturing after leaving the pupae stage. [8] [14] Within four days of emerging from the pupa stage, the adult C. macellaria become sexually mature and start looking for mates. The males will typically mate rapidly and will spend most of their time eating nearby vegetation and nectar from flowers. [14] The females, on the other hand, will feed on the fluids of live wounds from animals. Contrary to the males, the females will travel long distances to find mates. [13]
Depending on the gender and stage in their development, C. macellaria will utilize different resources for energy and nutrients. [14] During the larval stage, the C. macellaria will dig deeper into the necrotic wounds of their host animal and feed on the dead tissue. [14] Both males and females will feast through this method. [14] This time period is extremely crucial to the flies, as they must gather enough nutrients in order to last through the pupal stage without any food sources. This is one reason why the larvae are much larger than the size of the adult C. macellaria. [14]
As adults, the food specifications of the flies change. [14] Female flies will continue to feed on tissues of animals; however, now they preferentially feed off of live tissue and tissue plasma. Males, at this point, will no longer consume tissue, but instead will eat nearby vegetation and intake nutrients from the nectar of flowers. [14]
Although there are few studies on the mating patterns of C. macellaria, there is some information on the interactions between the males and females. Adult female C. macellaria have been observed to will release pheromones that will stimulate the males copulatory attempts on contact. Even though depriving the C. macellaria adults of dietary proteins did not impact the potency of the female extracts, there was a reduced response in males for the pheromones. [15]
Male C. macellaria do not provide parental care. The males will typically mate quickly and have the females bear the young. [4] [8] Since the females lay so many eggs, there is little care provided by the actual mothers after laying the eggs. The females do strategically lay the eggs in dead skin flesh so that once the eggs hatch into larvae, nutrition will be readily available. [4] [8]
Traditional social behavior like lekking has not been observed in C. macellaria; however, other social behaviors have been observed. [14]
It is common for female C. macellaria to lay eggs with other females. Since females may lay up to 250 eggs, it is common for aggregations of thousands of eggs to infest entire animal carcasses. [9]
While C. hominivorax is closely related to C. macellaria, there are evolutionary developed methods that lead to reproductive isolation. One of these mechanisms is the interspecies response to the C. macellaria female pheromone. Studies on newly colonized C. hoinivorax males have demonstrated that the males do not response to the C. macellaria pheromone. [15]
When studying the larval dispersal and predation for C. macellaria, studies have shown that there is interspecies competition and predation. [16] It has been demonstrated that C. albiceps larvae attack C. macellaria larvae during their dispersal process. [16] Additionally, C. macellaria showed higher aggregation level in single than in double species. This may be explained by an evolutionary mechanism used to conserve and protect C. macellaria from predation. [16]
Due to the medical and economic impact of the C. macellaria and other blowflies, an array of pesticides have been developed to reduce the C. macellaria population, including pyrethrin aerosol. [9]
While there are theories for protective coloration, there is no clear mimicry done by C. macellaria or by other insects specifically mimicking C. macellaria. The metallic green coloration may be a form of warding off predators, but this still in the process of being analyzed. [5]
Cochliomyia macellaria has extensive medical and economic implications. When C. macellaria larvae infest the dead and decaying tissues of animals or humans, myiasis may often occur. [16] Once infestation occurs, a dark brown discharge will start to leaking from the wound. As the infestation increases, there is more agitation and inflamed tissue, which is accompanied by unpleasant smells. [15] After the process of clinical diagnosis begins and the myiasis is recognized, then the larvae are easier to identify. Treatment of these infestations can be time intensive and leads to increased chances of reoccurrences. The first step is manual removal of the larvae followed by an antibiotic smear. [9]
The livestock industry considers the secondary screwworm an important pest because of the enormous economic losses caused by cases of myiasis and disease transmission. [15] The medical and pesticide treatment costs the United States millions of dollars annually. [17]
Cochliomyia macellaria is the most common species of blow flies found on carrion in the southern United States. [17] C. macellaria has recently gained recognition in forensic entomology because of its occurrence on decomposing remains. [17] Since the analysis of the succession and occurrence has been well defined, it is possible to create postmortem interval estimations, which are crucial for forensic entomology. [17] Adult C. macellaria in the southeastern United States are only attracted to the dead tissue on animals minutes after the death. In other regions of the United States, the adult flies are attracted to the dead flesh after a 24-hour delay. [17]
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.
Botflies, also known as warble flies, heel flies, and gadflies, are a family of flies known as the Oestridae. Their larvae are internal parasites of mammals, some species growing in the host's flesh and others within the gut. Dermatobia hominis is the only species of botfly known to parasitize humans routinely, though other species of flies cause myiasis in humans.
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.
Cochliomyia hominivorax, the New World screw-worm fly, or screw-worm for short, is a species of parasitic fly that is well known for the way in which its larvae (maggots) eat the living tissue of warm-blooded animals. It is present in the New World tropics. There are five species of Cochliomyia but only one species of screw-worm fly in the genus is parasitic; there is also a single Old World species in a different genus. Infestation of a live vertebrate animal by a maggot is technically called myiasis. While the maggots of many fly species eat dead flesh, and may occasionally infest an old and putrid wound, screw-worm maggots are unusual because they attack healthy tissue.
Chrysomya putoria, also known as the tropical African latrine blowfly, is a fly species belonging to the blowfly family, Calliphoridae.C. putoria is native to Africa and has recently spread to the Americas. These flies pose significant health risks, especially due to their close association with human settlements. Adult flies can carry pathogens, while larvae may cause myiasis by growing and feeding on the flesh of domestic animals and humans. Other myiasis-causing flies in the same genus are C. bezziana and C. megacephala. C. putoria and other flies that feed on decomposing tissue are used as important tools in forensic entomology to establish the post-mortem interval, or the time elapsed since death.
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.
Chrysomya albiceps is a species belonging to the blow fly family, Calliphoridae.
Chrysomya megacephala, more commonly known as the oriental latrine fly or oriental blue fly, is a member of the family Calliphoridae (blowflies). It is a warm-weather fly with a greenish-blue metallic box-like body. The fly infests corpses soon after death, making it important to forensic science. This fly is implicated in some public health issues; it can be the cause of myiasis, and also infects fish and livestock.
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.
The common toad fly, Lucilia silvarum, is a member of the fly family Calliphoridae. This fly was first discovered by Johann Wilhelm Meigen in 1826 and is found most notably in European and Western Countries.
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.
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.
Calliphora quadrimaculata, commonly known as the New Zealand blue blowfly and by its Māori name rango pango, is an insect in the genus Calliphora of family Calliphoridae in the order Diptera. This particular blowfly is found throughout New Zealand as well as on Chatham, Auckland, Stewart and Campbell Islands that surround New Zealand. Generally blowfly maggots in New Zealand have to feed on animal tissue or faeces to develop into adult blowflies. However the New Zealand blue blowfly larvae can survive on decaying leaves of snow tussock in alpine regions and reach adult maturity without feeding on any animal tissue.
Many species of flies of the two-winged type, Order Diptera, such as mosquitoes, horse-flies, blow-flies and warble-flies, cause direct parasitic disease to domestic animals, and transmit organisms that cause diseases. These infestations and infections cause distress to companion animals, and in livestock industry the financial costs of these diseases are high. These problems occur wherever domestic animals are reared. This article provides an overview of parasitic flies from a veterinary perspective, with emphasis on the disease-causing relationships between these flies and their host animals. The article is organized following the taxonomic hierarchy of these flies in the phylum Arthropoda, order Insecta. Families and genera of dipteran flies are emphasized rather than many individual species. Disease caused by the feeding activity of the flies is described here under parasitic disease. Disease caused by small pathogenic organisms that pass from the flies to domestic animals is described here under transmitted organisms; prominent examples are provided from the many species.