Hybotidae


Hybotidae, the typical dance flies, are a family of true flies. They belong to the superfamily Empidoidea and were formerly included in the Empididae as a subfamily.
Some, such as Tachydromia, are predators that run around on the bark of trees in complex patterns, hence the common name. Tachydromia species are only about three millimeters long.

Description

Hybotidae share some similarities with the family Dolichopodidae, when looking at rotation of genetalia and wing characteristics. Male terminalia are rotated dextrally between 45° and 90°, excluding segment 7. Hybotidae wings always have a simple R4+5 vein, where the costa either ends near or at M1/M1+2, or near or at R4+5/R5. Furthermore, it can be distinguished from Dolichopodidae by the point of vein Rs, which it at a distance from the humeral crossvein equal to or longer than the length of h.

Systematics

The Hybotidae clearly form a lineage quite distinct from the Empididae. Among the Empidoidea, they represent a lineage more basal than the main radiation of Empididae and Dolichopodidae, though they are not as ancient as the genera placed in the Atelestidae.
By and large, the Hybotidae are monophyletic. Among its subfamilies, the Hybotinae and Tachydromiinae certainly represent clades. The status of the Ocydromiinae as a natural group is less clear, in particular whether the Trichininae should be included as tribe Trichinini or even in the Bicellariini or Oedaleini, or whether they are more distinct and warrant recognition as a separate subfamily.
Based on the most recent phylogenetic studies, the relationship between Hybotidae and other members of Empidoidea is as follows. The placement of Hybotidae is emphasized in bold formatting.

Systematic list

The subfamilies with their tribes and selected genera are:
Hybotinae Meigen, 1820

Ocydromiinae
Trichininae
or closely related species
Tachydromiinae