Corethrellidae are a family of biting

midges A midge is any small fly, including species in several families of non-mosquito Nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid zones. Some midge ...

, small flying insects belonging to the order Diptera, females of which feed on the blood of

frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" '' Triadobatrachus'' is ...

s. The members of the family are sometimes known as frog-biting midges. The family currently consists of just one

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

, totalling 115 extant and 10 fossil species worldwide. Most

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

species are found in the lower latitudes, usually associated around the

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred ...

. They are tiny flies with a wing length of 0.6-2.5 mm. The wing venation is similar to Culicidae (R 4 branched, M 2 branched, Cu 2 branched) with branches of Rs and M nearly parallel. R1 is, however, closer to Sc or almost midway between Sc and R2. They were, from 1962 until 1989, placed as a tribe Corethrellini within the Chaoborinae, a subfamily of Culicidae. Adult female ''Corethrella'' are attracted to the mating calls of male

s, their chosen host taxa. As obligate external parasites, the midges feed almost exclusively on the blood of these frogs. Because of this, ''Corethrella'' follow typical distribution patterns of external parasites and are restricted to only areas with abundant populations of their host frogs. Female midges most likely detect their hosts using a specialized organ called a Johnston's organ, a collection of sensory cells found on the second antenna segment. There is evidence of host specificity and selection of particular biting sites for some species. ''Corethrella'' species have been observed sucking blood from individuals of the tree frog genus ''

Hyla ''Hyla'' is a genus of frogs in the tree frog family Hylidae. As traditionally defined, it was a wastebasket genus with more than 300 species found in Europe, Asia, Africa, and across the Americas. After a major revision of the family most of t ...

''. Specifically, the North American tree frog species ''

Hyla avivoca The bird-voiced tree frog (''Dryophytes avivoca'') is a species of frog in the family Hylidae, endemic to the United States. Its natural habitats are temperate forests, shrub-dominated wetlands, and swamps. Description The bird-voiced tree frog ...

'', ''

Hyla cinerea The American green tree frog (''Dryophytes cinereus'' or ''Hyla cinerea'') is a common arboreal species of New World tree frog belonging to the family Hylidae. This nocturnal insectivore is moderately sized and has a bright green to reddish-brow ...

'' and '' Hyla gratiosa'' were recorded as confirmed corethrellid hosts in a 1977 study. A few, select species are known

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

s of frog-specific species of the parasitic protozoan ''

Trypanosoma ''Trypanosoma'' is a genus of kinetoplastids (class Trypanosomatidae), a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek ''trypano-'' (b ...

''. Corethrellid parasitism is thus a recorded cause of

trypanosomiasis Trypanosomiasis or trypanosomosis is the name of several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus ''Trypanosoma''. In humans this includes African trypanosomiasis and Chagas disease. A number of other dise ...

among host frog populations. The family contains members that date to the lower

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Period some 110 million years ago. At least one species, ''

Corethrella andersoni ''Corethrella'' is a genus of midges that are classified in the family Corethrellidae Corethrellidae are a family of biting midges, small flying insects belonging to the order Diptera, females of which feed on the blood of frogs. The members o ...

'', has been found in

Burmese Burmese may refer to: * Something of, from, or related to Myanmar, a country in Southeast Asia * Burmese people * Burmese language * Burmese alphabet * Burmese cuisine * Burmese culture Animals * Burmese cat * Burmese chicken * Burmese (hor ...

amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In M ...

deposits dating from this time.

References

Bibliography

* * *

External links

* Corethrellidae in Italian {{Taxonbar, from=Q1627654 Nematocera families Culicoidea