Chironomidae  

Chironomidae (informally known as chironomids or nonbiting midges) are a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species superficially resemble mosquitoes, but they lack the wing scales and elongated mouthparts of the Culicidae.

Common names and biodiversity[edit]

This is a large taxon of insects; some estimates of the species numbers suggest well over 10000 world-wide.^[1] Males are easily recognized by their plumose antennae. Adults are known by a variety of vague and inconsistent common names, largely by confusion with other insects. For example, chironomids are known as "lake flies" in parts of Canada and Lake Winnebago, Wisconsin, but "bay flies" in the areas near the bay of Green Bay, Wisconsin. They are called "sand flies", "muckleheads",^[2] or "muffleheads"^[3] in various regions of the USA Great Lakes area. They have been called "blind mosquitoes" or "chizzywinks" in Florida, in northern Ohio, USA, and by Canadian soldiers.^[4] However, they are not mosquitoes of any sort, and the term "sandflies" generally refers to various species of biting flies unrelated to the Chironomidae.

The group includes Belgica antarctica, the largest terrestrial animal of Antarctica.

The biodiversity of Chironomidae often goes unnoticed because they are notoriously difficult to identify and ecologists usually record them by species groups. Each morphologically distinct group comprises a number of morphologically identical (sibling) species that can only be identified by rearing adult males or by cytogenetic analysis of the polytene chromosomes. Polytene chromosomes were originally observed in the larval salivary glands of Chironomus midges by Balbiani in 1881. They form through repeated rounds of DNA replication without cell division, resulting in characteristic light and dark banding patterns which can be used to identify inversions and deletions which allow species identification.

Behavior and description[edit]

Larval stages of Chironomidae can be found in almost any aquatic or semiaquatic habitat, including treeholes, bromeliads, rotting vegetation, soil, and in sewage and artificial containers. They form an important fraction of the macro zoobenthos of most freshwater ecosystems. They are often associated with degraded or low biodiversity ecosystems because some species have adapted to virtually anoxic conditions and are dominant in polluted waters. Larvae of some species are bright red in color due to a hemoglobin analog; these are often known as "bloodworms".^[5] Their ability to capture oxygen is further increased by their making undulating movements.^[6]

Many reference sources in the past century or so have repeated the assertion that Chironomidae do not feed as adults, but an increasing body of evidence contradicts this view. Adults of many species do in fact feed. The natural foods reported include fresh fly dropping, nectar, pollen and honeydew, and various sugar-rich materials.^[1]

The question whether feeding is of practical importance has by now been clearly settled for some Chironomus species, at least; specimens that had fed on sucrose flew far longer than starved specimens, and starved females longer than starved males, which suggested they had eclosed with larger reserves of energy than the males. Some authors suggest the females and males apply the resources obtained in feeding differently. Males expend the extra energy on flight, while females use their food resources to achieve longer lifespans. The respective strategies should be compatible with maximal probability of successful mating and reproduction in those species that do not mate immediately after eclosion, and in particular in species that have more than one egg mass maturing, the less developed masses being oviposited after a delay. Such variables also would be relevant to species that exploit wind for dispersal, laying eggs at intervals. Chironomids that feed on nectar or pollen may well be of importance as pollinators, but current evidence on such points is largely anecdotal. However, the content of protein and other nutrients in pollen, in comparison to nectar, might well contribute to the females' reproductive capacities.^[1]

Adults can be pests when they emerge in large numbers. They can damage paint, brick, and other surfaces with their droppings. When large numbers of adults die they can build up into malodorous piles. They can provoke allergic reactions in sensitive individuals.^[7]

Ecology[edit]

Larvae and pupae are important food items for fish, such as trout, Banded killifish, and sticklebacks, and for other aquatic organisms. An amphibian that eats them is the rough-skinned newt.^[8] Many aquatic insects, such as various predatory hemipterans in the families Nepidae, Notonectidae and Corixidae eat Chironomidae in their aquatic phases. So do predatory water beetles in families such as Dytiscidae and Hydrophilidae. Fly anglers design and tie imitators to catch trout. The flying midges are eaten by fish and insectivorous birds, such as swallows and martins. They also are preyed on by bats and flying predatory insects, such as Odonata and dance flies.

Chironomidae are important as indicator organisms, i.e., the presence, absence, or quantities of various species in a body of water can indicate whether pollutants are present. Also, their fossils are widely used by palaeolimnologists as indicators of past environmental changes, including past climatic variability.^[9]

Subfamilies and genera[edit]

The family is divided into 11 subfamilies: Aphroteniinae, Buchonomyiinae, Chilenomyinae, Chironominae, Diamesinae, Orthocladiinae, Podonominae, Prodiamesinae, Tanypodinae, Telmatogetoninae, Usambaromyiinae.^[10][11]

Chironomidae sp. female on flower of Euryops sp. damage caused by beetles in family Meloidae

Chironomidae larva, about 1 cm long, the head is right: The magnified tail details are from other images of the same animal.

Chironomidae larva showing the characteristic red color. ~40× magnification. The head is towards the upper left, just out of view

References[edit]

1. ^ ^{a b c} Armitage, P. D., Cranston, P. S., Pinder, L. C. V. (1995). The Chironomidae: biology and ecology of non-biting midges. London: Chapman & Hall. ISBN 0-412-45260-X. 
2. ^ "Muckleheads" from Andre's Weather World (Andre Bernier, staff at WJW-TV), June 2, 2007.
3. ^ "You don't love muffleheads, but Lake Erie does", Sandusky Register, May 29, 2007.
4. ^ "Chizzywinks are Blind Mosquitos by Dan Culbert of the University of Florida, August 17, 2005
5. ^ W.P. Coffman and L.C. Ferrington, Jr. 1996. Chironomidae. pp. 635-754. In: R.W. Merritt and K.W. Cummins, eds. An Introduction to the Aquatic Insects of North America. Kendall/Hunt Publishing Company.
6. ^ Int Panis, L; Goddeeris, B.; Verheyen, R (1996). "On the relationship between vertical microdistribution and adaptations to oxygen stress in littoral Chironomidae (Diptera)". Hydrobiologia 318: 61–67. doi:10.1007/BF00014132. 
7. ^ A. Ali. 1991. Perspectives on management of pestiferous Chironomidae (Diptera), an emerging global problem. Journal of the American Mosquito Control Association 7: 260-281.
8. ^ C. Michael Hogan (2008) Rough-skinned Newt (Taricha granulosa), Globaltwitcher, ed. Nicklas Stromberg [1]
9. ^ Walker, I. R. 2001. Midges: Chironomidae and related Diptera. pp. 43-66, In: J. P. Smol, H. J. B. Birks, and W. M. Last (eds). Tracking Environmental Change Using Lake Sediments. Volume 4. Zoological Indicators. Kluwer Academic Publishers, Dordrecht.
10. ^ J.H. Epler. 2001. Identification manual for the larval Chironomidae (Diptera) of North and South Carolina. North Carolina Department of Environment and Natural Resources.
11. ^ Armitage, P., Cranston, P.S., and Pinder, L.C.V. (eds.) (1994) The Chironomidae: Biology and Ecology of Non-biting Midges. Chapman and Hall, London, 572 pp.
12. ^ Ekrem, Torbjørn. "Systematics and biogeography of Zavrelia, Afrozavrelia and Stempellinella (Diptera: Chironomidae)". Retrieved 2009-04-30. 
13. ^ Makarchenko, Eugenyi A. (2005). "A new species of Arctodiamesa Makarchenko (Diptera: Chironomidae: Diamesinae) from the Russian Far East, with a key to known species of the genus" (PDF). Zootaxa 1084: 59–64. Retrieved 2009-04-03. 
14. ^ Caldwell, Broughton A.; Soponis, Annelle R. (1982). "Hudsonimyia Parrishi, a New Species of Tanypodinae (Diptera: Chironomidae) from Georgia" (PDF). The Florida Entomologist (Lutz, FL, USA: Florida Entomological Society) 65 (4): 506–513. doi:10.2307/3494686. ISSN 0015-4040. JSTOR 3494686. Retrieved 2009-04-20. 
15. ^ Halvorsen, Godtfred A. (1982). "Saetheriella amplicristata gen. n., sp. n., a new Orthocladiinae (Diptera: Chironomidae) from Tennessee". Aquatic Insects, International Journal of Freshwater Entomology (Taylor & Francis) 4 (3): 131–136. doi:10.1080/01650428209361098. ISSN 1744-4152. 
16. ^ Andersen, Trond; Sæther, Ole A. (January 1994). "Usambaromyia nigrala gen. n., sp. n., and Usambaromyiinae, a new subfamily among the Chironomidae (Diptera)". Aquatic Insects, International Journal of Freshwater Entomology (Taylor & Francis) 16 (1): 21–29. doi:10.1080/01650429409361531. ISSN 1744-4152.