TABANOMORPHA, Hennig, 1948

Grimaldi, David A., 2016, Diverse Orthorrhaphan Flies (Insecta: Diptera: Brachycera) In Amber From The Cretaceous Of Myanmar: Brachycera In Cretaceous Amber, Part Vii David A. Grimaldi, Bulletin of the American Museum of Natural History 2016 (408), pp. 1-132 : 30-31

INFRAORDER TABANOMORPHA

This is a monophyletic group of some 5300 species in five extant families. Although there is a diverse fossil record of tabanomorphs that extends into the Jurassic and Cretaceous, there are no extinct families. Jurassic and Cretaceous fossils attributed to the Rhagionidae are very diverse, but many of them are taxonomically problematic. As a result, I have generally avoided the Rhagionidae in Burmese amber for this study, with the exception of four taxa that have some similarities to Athericidae and to spaniine rhagionids, but which I have left incertae sedis within Tabanomorpha .

In Tabanomorpha the small, relict families Pelecorhynchidae (50 species) and Oreoleptidae (1 species) have no fossil record. Pelecorhynchidae contains two or three genera and 51 species: Glutops Burgess (11 species: Holarctic), Pelecorhynchus Macquart (38 species: Australia and Tasmania [ Mackerras and Fuller, 1942], Chile [ Llanos et al., 2015]), and Pseudoerinna Shiraki (2 species: Asia, sometimes put into Rhagionidae ). These are generally stout, pilose flies, inhabiting xeric areas where they feed from flowers. The monotypic Oreoleptis Zloty et al. (Oreoleptidae) is known only from western North America, where it has been reared from larvae living in cold streams in the Cascade Mountains in Washington and the Rocky Mountains in Alberta ( Zloty et al., 2005). Oreoleptis larvae have prolegs that are even longer than those in athericid larvae ( Zloty et al., 2005). Qiyia jurassica , from the Daohugou beds (Middle Jurassic of Inner Mongolia, China (Chen et al., 2014), is known entirely as larvae. It was placed in Athericidae based on its seven pairs of crocheted prolegs and long anal tubercles, although it uniquely possesses a median, radial structure on the ventral side of the thorax, interpreted as a sucker used for putatively parasitizing the salamanders that are abundant in this deposit (Chen et al., 2014). The larvae of all tabanomorphs, where their diet is definitely known, are predaceous, and have features that partly define the group, including the possession of a poison canal on the larval mandible. Other defining features, in the adult, include an inflated or bulbous clypeal region laterally bounded by deep paraclypeal sulci and by a cercus with a ventral lobe in the female.

Relationships among families of the “tabanoid” group are well established: Pelecorhynchidae ( Oreoleptidae ( Athericidae + Tabanidae )), based on morphological and molecular studies ( Hennig, 1973; Stuckenberg, 1973; Nagatomi, 1977; Woodley, 1989; Zloty et al., 2005; Kerr, 2010; Wiegmann et al., 2011). Rhagionidae in its modern sense ( Kerr, 2010) are the sister group to the Tabanoidea, and Vermileonidae are either a sister group to Rhagionidae or to Rhagionidae and all other tabanomorphs ( Woodley, 1989; Kerr, 2010; Zloty et al., 2005; Wiegmann et al., 2011). The phylogenetic position of Vermileonidae has traditionally been ambiguous.

The sister-group relationship of Athericidae + Tabanidae is very well supported ( Stuckenberg, 1973; Woodley, 1989; Kerr, 2010; Wiegmann et al., 2011). Defining morphological features include a “scale” (small, flattened lobe) immediately posterior to the hind thoracic spiracle; tergite 1 divided along the midline; a compact, dorsoventrally flattened abdomen; a 1-segmented cercus; R 4 -R 5 often widely divergent and encompassing the wing tip, with R 4 sinuous; and a small proscutellum present (although this also occurs in Pelecorhynchidae , but not in Oreoleptis ). Further, the epandrium is enlarged and elongate in both families ( Stuckenberg, 1973), males have aedeagal tines, and the female labrum has a dorsoproximal process ( Nagatomi and Soroida, 1985).

Tabanomorpha is notorious for the hematophagous females of most species of Tabanidae , many Athericidae , and some Rhagionidae (reviewed by Nagatomi and Soroida, 1985; Kerr, 2010). Based on relationships it appears that hematophagy arose twice in tabanomorphs: once in Tabanidae + Athericidae , and again in the closely related, relatively derived rhagionid genera Symphoromyia Frauenfeld (Holarctic: 36 species) and Spaniopsis White ( Australia: 7 species) ( Kerr, 2010). In hema- tophagous tabanomorphs the mandibles, hypopharynx, and laciniae are approximately equal in length to the labrum, instead of shorter ( Nagatomi and Soroida, 1985), as well as having the tips of the mandibles finely serrate.

Striking new stem-group tabanomorphs and Tabanidae are described from mid-Cretaceous Burmese amber, below. Based on the long mandibles with serrate tips in the females of Atherhagiox simulans , n. gen., n. sp., and Galloatherix completus , n. sp., these species appear to have been hematophagous. Features of many of the fossils are revealing about the chronology of characters that partly define Athericidae and Tabanidae , such as 1-segmented cerci and a postmetaspiracular scale.