Calliphoridae
| Blow-fly | |
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| Blowfly | |
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| Family: | Calliphoridae
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Blow-flies (also frequently spelled blow flies or blowflies) are members of the family Calliphoridae of flies (Diptera). Flies in this family are often metallic in appearance and between 10 to 12mm in length.
Some members of this family are known as bluebottles, clusterflies or greenbottles. The name blow-fly comes from an older English term for meat that had eggs laid on it, which was said to be fly blown. The first association of the term “blow” with flies was used by Shakespeare in his plays Loves Labour Lost, The Tempest, and Antony and Cleopatra.
Blow-flies are usually the first insect to come in contact with carrion because they have the ability to smell death from up to ten miles away. Upon reaching the carrion, females deposit eggs onto the body. Forensic entomologists have begun to use the information to determine a person’s time of death at crime scenes.
Description
Characteristics
Calliphoridae adults are known for being shiny with metallic coloring, often with blue, green, or black bodies. Antennae are 3-segmented, aristate. The arista are plumose the entire length, and the second antennal segment is distinctly grooved. Members of Calliphoridae have vein Rs 2-branched, frontal suture present, and well developed calypters.
The characteristics and arrangement of hairs are used to tell the difference between members of this family. All blow-flies have bristles located on the meron. Having two notopleural bristles and a hindmost posthumeral bristle located lateral to presutural bristle are characteristics to look for when identifying this family.
The thorax has the continuous dorsal suture across the middle, along with well defined posterior calli. The postscutellum is absent or weakly developed. The costa is unbroken and the sub-costa is apparent on the insect.
Blowflies have a 'miniature gearbox' at the base of the wing which they can use to select different degrees of leverage against the air for different types of flight[1].
For a pictorial atlas explaining these terms go to [1]
- Key to the Calyptrate families
- Useful site for diagnostic features. (In French
- Japanese Calliphoridae
Development
Most species of blowflies studied thus far are anautogenous; a female requires a substantial amount of protein to develop mature eggs within her ovaries (about 800 µg per pair of ovaries in Phormia regina). The current theory is that females visit carrion both for protein and egg laying, but this remains to be proven. Blow-fly eggs are approximately 1.5 mm x 0.4 mm, are yellowish or white, and when laid, look like rice balls. While the female blow-fly typically lays 150-200 eggs per batch, she is usually iteroparous, laying around 2,000 eggs during the course of her life. The sex ratio of blowfly eggs is usually 50:50, but one interesting exception is currently documented in the literature. Females from two species of the genus Chrysomya (C. rufifaces and C. albiceps) are either arrhenogenic (laying only male offspring) or thelygenic (laying only female offspring).
Hatching from an egg to the first larval stage takes about 8 hours to one day. Larvae have three stages of development (called instars); each stage is separated by a molting event.The instars are separable by examining the posterior spiracles, or openings to the breathing system [2]. The larvae use proteolytic enzymes in their excreta (as well as mechanical grinding by mouth hooks) to break down proteins on the livestock or corpse they are feeding on. Blowflies are poikilothermic, which is to say that the rate at which they grow and develop is highly dependent on temperature and species. Under room temperature (about 30 degrees celsius) the black blowfly Phormia regina can go from egg to pupa in 150-266 hours (6 to 11 days). When the third stage is complete the pupa will leave the corpse and burrow into the ground, emerging as an adult 7 to 14 days later.
![[2]](http://www.smlc.asso.fr/smlc/dmla/entomologie/diaporama/images/08.jpg){kind=link}
Food Sources
Adult blow-flies are occasional pollinators, being attracted to flowers with a strong odor resembling rotting meat, such as the American pawpaw or Dead Horse Arum. There is little doubt that these flies utilize nectar as a source of carbohydrates to fuel flight, but just how and when this happens is unknown.
Larvae of most species are scavengers of carrion and dung and most likely constitute the majority of the maggots found in such material, although it is not uncommon for them to be found in close associate with other dipterous larvae from the families Sarcophagidae, Muscidae, and many other acalyptrate muscoid flies.
Diversity
Worldwide, there are 1100 species of blowflies, with 228 species in the Neotropics, but very numerous species in Africa and Southern Europe. The family is divided into subfamilies, the Calliphorinae, and the Chrysomyinae, which between them contain about 23 genera.
Economic Importance
Myiasis
Blowflies have caught the interest of researchers in a variety of fields, although the large body of literature on calliphorids has been concentrated on solving the problem of myiasis in livestock. It is estimated that the sheep blowfly Lucilia cuprina causes the Australian sheep industry over $170 million a year in losses. While much of the biology of these flies has been studied in the laboratory, the natural life history of the blowflies remains a largely untapped body of research.
Screwworms
The Primary Screwworm (Cochliomyia hominivorax) once a major pest in southern United States, has been eradicated through massive release of sterilized males. See Sterile insect technique.
Maggot Therapy
Lucilia sericata (Phaenicia sericata), or the common green bottle fly, is the preferred species of maggot used for maggot-debridement also, called Maggot therapy. [2]
Blowfly maggots have also been used successfully in the treatment of badly infected wounds: see maggot therapy, although maggots have been known to eat away healthy tissues as well[citation needed].
Disease
Adults may vector pathogens of diseases such as dysentery.
Forensic Importance
Since development is highly predictable if the ambient temperature is known, blow-flies are considered a valuable tool in forensic science. Traditional estimations of time since death (namely rigor mortis and algor mortis) are generally unreliable after 72 hours and often entomologists are the only officials capable of generating an accurate approximate time interval. The specialized discipline related to this practice is known as forensic entomology [3]
Calliphora vicina and Cynomya mortuorum are important flies of forensic entomology.
Other forensically important Calliphoridae are Phormia regina, Calliphora vomitoria, Calliphora livida, Lucilia cuprina, Lucilia sericata, Lucilia illustris, Chrysomya rufifacies, Chrysomya megacephala, and Cochliomyia macellaria. One interesting myth states that species from Lucilia can sense death and show up right before it even occurs.
Pest control
In order to reduce the number of blowflies entering the home, a number of procedures can be adopted; these include: Improving sanitation, using sprays and poisons.
Improved sanitation
Improving the sanitary levels within, and outside the home will go a long way to destroying the habitat in which the blowflies thrive.
In order to reach this goal certain rules of thumb should be followed. Firstly, ensure that all scraps of food – especially fruit, vegetables and meat – are discarded properly. It’s preferable to place these scraps into a sturdy dustbin or trash can with a tight fitting lid; by storing those in this way the vessels are less likely to be knocked over by scavenging animals, thus not exposing the contents to the elements and even more, the blowflies.
Secondly, it must be noted that the bins should be situated as far away from the premises as possible. This will limit the chance of other pests entering your home - once they realize they can’t get at the contents of the said bins.
Additionally, cleaning methods should be put into play when combating this particular kind of pest. Not only must care be taken in ensuring the inside of the bins are regularly cleaned but more importantly their outsides and the immediate area surrounding too.
Identification
- Fritz Konrad Ernst Zumpt Calliphorinae, in Lindner, E. Fliegen Palaearkt. Reg. 64i, 140 p. (1956)
- Fan, C.T. Key to the common synanthropic flies of China. Peking [= Beijing]. xv + 330 p. In Chinese but really excellent illustrations. (1965).
- Kano, R. and Shinonaga, S. Calliphoridae (Insecta: Diptera) (Fauna Japonica) , Tokyo Biogeographical Society of Japan, Tokyo.( 1968). In English.
- Lehrer, A.Z., Diptera. Familia Calliphoridae. In: Fauna R.S.R., Insecta, vol. XI,(12), Edit. R.S.R., Bucuresti, 1972, 245 p. In Romanian.
- Rognes, K. Blowflies (Diptera: Calliphoridae) of Fennoscandia and Denmark. Fauna Entomologica Scandinavica, Volume 24.
- E. J. Brill/Scandinavian Science Press Ltd. Leiden.(1991).
Genera and Species
According to Keys to the Genera and Species of Blow Flies (Diptera: Calliphoridae) of America North of Mexico by Terry Whitworth
· Bellardia
- Bellardia bayeri
- Bellardia vulgaris
· Calliphora – Blue bottle flies, Bluebottles
- Calliphora alaskensis
- Calliphora aldrichia
- Calliphora coloradensis
- Calliphora genarum
- Calliphora grahami
- Calliphora latifrons
- Calliphora livida
- Calliphora loewi
- Calliphora montana
- Calliphora stelviana
- Calliphora vicina
- Calliphora terraenovae
- Calliphora vomitoria
· Cyanus
- Cyanus elongate
· Cynomya
- Cynomya cadaverina
- Cynomya mortuorum
· Chloroprocta
- Chloroprocta idioidea
· Chrysomya – Old World screw-worms
- Chrysomya megacephala
- Chrysomya rufifacies
· Cochliomyia – New World screw-worms
- Cochliomyia aldrichi
- Cochilomyia hominivorax
- Cochilomyia macellaria
- Cochilomyia minima
· Compsomyiops
- Compsomyiops callipes
· Phormia
- Phormia regina
· Protocalliphora
- Protocalliphora beameri
- Protocalliphora bennetti
- Protocalliphora bicolor
- Protocalliphora hirundo
- Protocalliphora interrupta
- Protocalliphora metallic
- Protocalliphora parorum
- Protocalliphora bennetti
- Protocalliphora rugosa
- Protocalliphora sapphire
- Protocalliphora sialia
- Protocalliphora occidentalis
· Protophormia
- Protophormia atriceps
- Protophormia terraenovae
· Trypocalliphora
- Trypocalliphora braueri
· Lucilia – Greenbottles
- Lucilia cluvia
- Lucilia coeruleiviridis
- Lucilia cuprina
- Lucilia elongata
- Lucilia eximia
- Lucilia illustris
- Lucilia magnicornis
- Lucilia mexicana
- Lucilia sericata
- Lucilia silvarun
- Lucilia thatuna
· Melondexia
- Species still to be determined
- Pollenia angustigena
- Pollenia griseotomentosa
- Pollenia labialis
- Pollenia pediculata
- Pollenia rudis
- Pollenia vagabunda
· Angioneura
- Five species
· Opsodexia
- Four species
External links
References
Brundage, Adrienne, “Calliphoridae.” Texas A&M University, College Station. 13-15 Feb. 2008.
Catts, Paul, ed & Haskell, Neal, ed. Entomology & Death: A Procedural Guide. South Carolina: Joyce Print Shop, Inc, 2005.
Goodman, L.J. (1960). The Landing Responses of Insects. The Journal of Experimental Biology, retrieved March 18, 2008, from http://jeb.biologists.org/cgi/reprint/41/2/403.pdf.