Sinclair: Hydropeza empidid flies of Australia 
3 
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 rhagas (payaq), with genitive 
rhagados (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.). 
Genus Hydropeza Sinclair 
Hydropeza Sinclair, 1999: 135. Type-species: Hydropeza 
longipennae (Miller). 
Diagnosis. This genus can be identified using the key 
to subfamilies and genus groups in Sinclair (2011), 
characterized by its long and apically rounded cell cua, 
pterostigma absent (Fig. 28), pubescent eyes (Fig. 13), fore 
coxa with spine-like setae (Fig. 14), bare laterotergite and 
recurved labrum (Figs 1, 3-6, 13). 
Description. See Sinclair (1999) for description, with the 
following addition: male cercus undivided and continuous 
posteromedially with subepandrial sclerite or often 
subdivided into short anterior lobe and short to elongate 
posterior lobe (often termed clasping cercus); posterior 
cercus medially continuous with subepandrial sclerite. 
Remarks. There are 11 described species of Hydropeza from 
New Zealand and Chile (Fig. 30) (Sinclair & McLellan, 
2004; Sinclair & Plant, 2008). This study builds on these 
studies and describes the nine species from Australia. In a 
preliminary phylogenetic analysis, the//, longipennae-group 
of New Zealand was assigned as sister to the remaining 
species of the genus. The remaining New Zealand species 
were assigned to a monophyletic clade (Sinclair & McLellan, 
2004). The phylogeny of the Hydropeza is reanalysed in this 
study (see below). 
Key to Australian species of Hydropeza 
Most females from Queensland are not readily identifiable due to similar terminalia and uncertainty 
concerning variation. More study on positively associated females from Queensland is required. 
1 Wings reduced to halter-like appendages; head and body 
chaetotaxy greatly reduced and slender; eyes closely approx¬ 
imated below antennae (Figs 1, 3). H aptera sp. nov. 
- Wings fully developed; head and body chaetotaxy very long and 
bristle-like (Figs 4-6); eyes widely separated below antennae.2 
2 Acrostichal setae present posterior to first pair of dorsocentral 
setae (females not readily distinguishable in the following species). 3 
- Acrostichal setae confined anteriorly to first pair of dorsocentral 
setae. 5 
3 Male cercus unforked; phallus inflated with highly modified apex 
comprised of lobes and jagged edges (Fig. 24); female abdominal 
segment 8 distinctly swollen . H. intricata sp. nov. 
- Male cercus forked; phallus flattened with simple apex; female 
segment 8 not swollen. 4 
4 Male cercus U-shaped; upper branch straight with apex rounded 
(Fig. 23). H. divaricata sp. nov. 
- Male cercus V-shaped; upper branch slightly twisted with narrow 
apex (Fig. 12) 
H. curvata sp. nov. 
