Gigantodax

Taxobox
name = Gigantodax


image_width =
image_caption =
regnum = Animalia
phylum = Arthropoda
subphylum = Hexapoda
classis = Insecta
subclassis = Pterygota
infraclassis = Neoptera
superordo = Endopterygota|
ordo = Diptera
subordo = Nematocera
infraordo = Culicomorpha
superfamilia = Chironomoidea
familia = Simuliidae
subfamilia = Simuliinae
trubus = Simuliini
genus = "Gigantodax"
subdivision_ranks = Species
subdivision =See text

"Gigantodax" is a genus of 71 species of black flies distributed along the Andes from Mexico to Tierra del Fuego in Argentina. [http://www.bioline.org.br/request?oc98088] The Polytene Chromosomes of Cnesia dissimilis (Edwards) and Three Species of Gigantodax Enderlein (Diptera: Simuliidae) from Lanin National Park (Argentina) by Cecilia L Coscaron Arias] [ [http://entweb.clemson.edu/biomia/black_flies/coll.html] Clemson University Department of Entomology, Soils, & Plant Sciences]

The taxonomy of the genus was revised in 1989 by an academic paper published in the bulletin of the American Museum of Natural History. [http://digitallibrary.amnh.org/dspace/handle/2246/935] Revision of the black fly genus Gigantodax (Diptera, Simuliidae). Bulletin of the American Museum of Natural History, 1989] In 1997, researchers from the "Universidad Nacional del Comahue" in Rio Negro, Argentina collected larvae of "G. marginalis" and other fly species in Lanin National Park, Neuquén Province. After a close examination included chromosome mapping, they reported:

Females are not anthropophilic and can be found as well as in mountain creeks from sea level to 4,700 m of altitude (Wygodzinsky & Coscaron 1989). "Gigantodax" is a peculiar genus, showing the greatest diversity among the Prosimuliini genera, with synapomorphies in imago and preimaginal stages that help to differentiate species in this genus from other genera. The unusual morphology of the respiratory filaments in the pupal stage is useful in differentiating species.

These South American researchers also analyzed "G. marginalis", "G. fulvescens", and "G. chilensis" and reported that "Cnesia", another Prosimuliini genus, is sympatric with southern populations of Gigantodax and that both genera breed on both sides of the Andean range in Argentina and Chile in subantarctic Patagonia. They also reported that "Gigantodax" species in this area are also sympatric with "Simulium".

These genus was re-examined in 2007 by entomologits from the Universidade Federal do Rio de Janeiro in Brazil who explained that in their paper:

...the first phylogenetic hypothesis for the 13 Southern Hemisphere genera of Simuliidae is proposed, through a cladistic approach. In order to investigate the position of those genera representatives of five Northern Hemisphere genera were also included in the analyses as outgroups. The study was based on a data matrix with 33 terminal taxa and 119 morphological characters of adult, pupa and larva. The phylogenetic analysis under equal weights resulted in four most parsimonious trees, with similar topologies and 349 steps... [http://www.mapress.com/zootaxa/2007f/z01643p068f.pdf] Preliminary considerations on phylogeny of Simuliidae Genera from SouthernHemisphere (Insecta, Diptera)]

References