Extant forms of ditomyiids are found most commonly in the Australasian and Neotropical Regions. There are almost 100 species known in 8 genera distributed in all regions of the globe except the Afrotropical. Adults are primarily forest dwelling. Immatures have been found living in bracket fungi and rotten wood where they make galleries.
Ditomyiids are apparently a relatively young group geologically. The oldest fossils found thus far have been from the Eocene deposits of the Redbank Plains Series of southeastern Australia.
Ref.: Munroe (1974, phylogeny and zoogeography of Australosymmerus and Symmerus).
*CENTROCNEMIS Philippi, 1865: 619. Type species: Centrocnemis
stigmatica Philippi, 1865, by monotypy. [Preoccupied by Signoret, 1852.]
*AUSTRALOMYIA Freeman, 1951: 7 (new replacement name for Centrocnemis Philippi). Type species: Centrocnemis stigmatica Philippi, 1865, automatic. [Preoccupied by Schmid, 1950.]
*AUSTRALOSYMMERUS Freeman, 1954: 39 (new replacement name for Australomyia Freeman). Type species: Centrocnemis stigmatica Philippi, 1865, automatic.
imperfectus Riek, 1954: 59 (Centrocnemis). AU: Australia (Eocene) [C].
*DITOMYIA Winnertz, 1846: 14. Type species: Ditomyia trifasciata
Winnertz, 1846 [= Mycetobia fasciata Meigen, 1818], by monotypy.
pilosella Statz, 1944a: 69. PA: Germany (Oligocene) [C].
*SYMMERUS Walker, 1848: 88. Type species: Symmerus ferrugineus
Walker, 1848 [= Mycetobia annulata Meigen, 1830], by monotypy.
balticus Edwards, 1921a: 435. PA: Baltic Region (Eocene/Oligocene) [A].
defectivus Loew, 1850b: 35 (Mycetobia). PA: Baltic Region (Eocene/Oligocene) [A].