Ragadinae, Sinclair, 2016

Sinclair, Bradley J., 2016, Revision of the Australian species of Hydropeza Sinclair (Diptera: Empididae: Ragadinae subfam. nov.), Records of the Australian Museum 68 (1), pp. 1-22 : 2-3

Subfamily Ragadinae subfam. nov.

Type-genus: Ragas Walker, 1837: 229 .

Diagnosis. Males dichoptic or holoptic; eyes with or without ommatrichia; scape with setae (absent in Hormopeza Zetterstedt ); labrum stout and recurved at least in females, lacinia freely projecting; apical epipharyngeal comb present (absent in Hydropeza ); laterotergite bare (except Dipsomyia Bezzi ); fore coxa with erect, spine-like setae (absent in Hormopeza ); costa circumambient (although sometimes weakened posteriorly); R 4+5 branched; apex of phallus often emitting membranous tube; female cercus short, broad with fine setae ( Sinclair, 1999; Sinclair & Cumming, 2006).

Remarks. The Ragas genus group was first proposed by Sinclair (1999) and keyed out from other major groups of Empidoidea by Sinclair & Cumming (2006). The group is herein given subfamily status, although its precise position within the Empididae remains unresolved (Sinclair & Cumming, 2006). The subfamily is named to provide stability in Empidoidea nomenclature, and to highlight the importance of including this clade in future molecular and morphological phylogenetic studies.

The presence of Baltic amber species of Ragas Walker indicates that the subfamily is as old as the Dolichopodidae s.str. (minimum age: 40 million years) and could perhaps be found in Upper Cretaceous amber ( Ulrich, 2003; Sinclair & Hoffeins, 2013). The Gondwanan distribution of Hydropeza implies an even older minimum age (see below).

The Ragadinae includes the genera: Dipsomyia Bezzi , Hormopeza Zetterstedt , Hydropeza Sinclair , Ragas Walker , and Zanclotus Wilder ( Sinclair, 1999; Sinclair & Cumming, 2006). Only Hydropeza and Hormopeza are recorded from Australia ( Sinclair, 1995).

Etymology. The type genus, Ragas (gender feminine) is derived from the Greek word rhagás (ῥαγάς), with genitive rhagádos (Latin rhagadis), which in medicine refers to fissures or cracks in the skin. It is not obvious what its meaning might have in common with the fly named by Walker. Given the Greek source of the generic name, the stem of Ragas is ragad- and consequently the subfamily is Ragadinae (Ulrich, pers. comm.).