Biogeography deals with the distribution of taxa around the planet in space and time, and the factors influencing this distribution. It includes understanding how modes of dispersal have affected which taxa are cosmopolitan (found worldwide), which are endemic (only found in limited regions), and which have disjunct (widely separated) distributions that may be explained by larger processes such as plate tectonics (changing position of landmasses over geologic time due to shifting of the earth’s plates), landscape and climatic features that provide opportunities and corridors of dispersal, and catastropic changes to an environment, such as volcanic eruptions. Combining the evidence from biogeography and that of genetic relationships among taxa through phylogenetic studies of their “family tree,” scientists are able to make hypotheses about the when, how, and why taxonomic groups are distributed as we find them today or in the fossil record.

In the present time, therevids have been found in all of the biogeographic regions (Afrotropical, Australasian, Nearctic, Neotropical, Palearctic, Oceanian, and Oriental) except the Antarctic. The family is thought to have arisen in the Jurassic when the continents had coalesced into the supercontinent of Pangea, about 200 million years ago. Fossil evidence indicates that both the Therevidae and its sister family, Scenopenidae had already differentiated by the Upper Jurassic. This is consistent with the likely Triassic origin of the Brachycera and rise of other asiloids in the Jurassic (Gaimari and Irwin 2000).

Choose a biogeographic region:

Nearctic

• Southern California, Guadalupe-Nipomo Dunes
• Sierra San Pedro Martir, Baja California, Mexico
• Sand Ridge State Forest, Mason County, Illinois
• Washington State
• List of Nearctic Therevid Names
• Key to Nearctic Therevid Genera — NOTE FOR GAIL: KEYS NOT MIGRATED; YOU CAN FIND THE MATERIAL ON BOX

Palearctic

• 2000 Collecting Trip to Tunisia
• 2000 Collecting Trips to Spain & Greece
• List of Palearctic Therevid Names

Australasian & Oceanian

• Catalog of the Therevids of the Australasian/Oceanian Region, from: Irwin, M. E., L. Lyneborg 1989. 39. Family Therevidae. N. L. Evenhuis [eds] Catalog of the Diptera of the Australasian and Oceanian Regions.
• Expanded List of Australasian & Oceanian Therevid Names
• Great Sandy National Park, Cooloola Section, Australia
• Birdsville, Wyperfeld National Park, Flinders Range, & Warrumbungle National Park
• Long-term Malaise Trapping Survey near Brisbane, Australia
• Finding Clesthentia White in Tasmania

Oriental

• List of Oriental Therevid Names

Afrotropical

• 96 Expedition to Southern Africa
• Species composition and flight phenology of stiletto flies and window flies occurring along the Kuiseb River, Gobabeb, Namibia
• 1998 Exploratory Expedition to Madagascar
• List of Afrotropical Therevid Names

Neotropical

• 1997 Expedition to Guatemala
• 1997 Expedition to Chile & Argentina
• List of Neotropical Therevid Names

Antarctic

It’s too cold in the Antarctic region to support any therevid fauna!

Read more about biogeography

• New York University biogeography website
• University of British Columbia: Explore the World’s Biomes
• UCMP: Plate Tectonics and Continental Drift
• Link for Pangea: Paleomap Project

Relevant Publications

• Gaimari, S.D. and Irwin, M.E. (2000). Phylogeny, classification, and biogeography of the cycloteline Therevinae (Insecta: Diptera: Therevidae). Zoological Journal of the Linnean Society, 129: 129-240.
• Grund, M. & Hauser, M. (2005): Pachygaster hymenaea sp. nov. and P. antiqua James,1971 (Diptera: Stratiomyidae) in Neotropical ambers. Zootaxa. 1061: 29–34.
• Hauser, M. & M. E. Irwin (2005): A new remarkable Xestomyzinae (Insecta, Diptera, Therevidae) genus from Mexican Amber. Zootaxa 1008: 39-45.
• Hauser, M. & M. E. Irwin (2005): Fossil Therevidae (Insecta: Diptera) from Florissant, Colorado. Journal of Systematic Palaeontology 3(4): 393-401.
• Hauser, M. & S. L. Winterton (in press): A new fossil genus of small-headed flies (Diptera: Acroceridae: Philopotinae) from Baltic Amber. Annals of the Entomological Society of America