Sinclair: Hydropeza empidid flies of Australia 
11 
truncate apically, clothed in fine setae only. Hypandrium 
keel-like, prolonged dorsally into phallic guide; gonocoxal 
apodeme small, rounded; apex of hypandrium flattened and 
broad surrounding emerging phallus; postgonites appear 
fused to apex of hypandrium. Phallus strongly arched at 
base, tapered to slender recurved tip; ejaculatory apodeme 
small, apical margin expanded. 
Female. Similar to male except as follows: stout setae on 
fore and midlegs longer and more pronounced. T10 divided 
medially. Cercus short and rounded apically, slightly longer 
than width, shorter than length of tergite 10. 
Distribution. This species is restricted to Tasmania (Fig. 21), 
currently known only from the type-locality and apparently 
active in cold months, from May to September [minimum 
temperature: July 3.2°C (Dreissen etal., 2013)]. 
Etymology. The specific name is derived from the Greek 
apteros (wingless), referring to the virtual absence of wings 
in this species. 
Remarks. All specimens were collected in pitfall traps set 
out in buttongrass moorland (Fig. 2), which at this location 
has a shrubby element (Myrtaceae, Epacridaceae) as well 
as monocots (Cyperaceae and Restionaceae) dominated 
by buttongrass (Driessen et al ., 2013). The habitat at 
approximately 320 m includes many standing pools and 
riddled with water-filled crayfish burrows (Driessen, pers. 
comm., 2014). Small streams run through the plains and 
large lakes occur nearby. In addition, the waters are highly 
acidic (around pH 4). A montane moorland site (Lake St. 
Clair, approx. 800 m) was also surveyed by Driessen et al. 
(2013), but these flightless empidids were not collected. 
Wingless or flightlessness among Empidoidea is possibly 
an adaptation for increased running ability among secretive 
habitats such as the grasses of the moorland and/or an 
adaptation to cold conditions which make thermoregulation 
of thoracic flight muscles difficult (Hackman, 1964; 
Bickel, 2006). Included among the pitfall trap samples 
from McPartlan Pass was another wingless empidoid, 
Apterodromia tasmanica Sinclair & Cumming (Hybotidae: 
Ocydromiinae). This latter species was originally known 
from litter samples, collected in January and March (Sinclair 
& Cumming, 2000). Ground predation, particularly from ants 
has been cited as a major factor limiting wider development 
of flightlessness in Diptera (Bickel, 2006). However, ant 
abundance was only lower during the cold months compared 
to warm months at this lowland moorland (Driessen et al ., 
2013, fig. 1). 
Hydropeza cornuta sp. nov. 
Figs 8, 11 
Type material. Holotype S, labelled: “AUST: N.QLD:/ 
31.6km/ up Mt. Lewis Rd., 1000m/ 21.iv.1994, cascading/ 
creek, B. J. Sinclair/ 16°30'S 145°17'E”; “HOLOTYPE/ 
Hydropeza/ cornuta/ Sinclair [red label]” (AMS). Paratypes: 
Queensland: lc?, 14.7 km up Mt. Lewis Rd., 860 m, 
22.iv. 1994, cascading ck, 16°30'S 145°17'E, B. J. Sinclair 
(CNC); 1&25 km up Mt. Lewis Rd., 1000 m, 22.iv.1994, 
roadside pools, 16°32'S 145°17'E, B. J. Sinclair (CNC); 
iSS, 31.6 km up Mt. Lewis Rd., 1000 m, 21.iv.1994, 
cascading ck, 16°30’S 145°17'E, B. J. Sinclair (AMS, CNC). 
Diagnosis. This species is distinguished from other 
Queensland species by acrostichal setae confined anteriad 
of an imaginary line connecting the first (anteriormost) 
dorsocentral setae; male scutellum with at most 1-2 pairs 
of elongate discal setae; male mid femur with short row 
of basal posteroventral setae and mid tibia with short row 
of spine-like setae on apical third; male hind trochanter 
with spine-like anteroventral seta; and male cercus long, 
projecting and antler-like. 
Description. Head and abdomen dark brown, thorax 
brown with paler patches; coxae brownish yellow, legs 
progressively darker towards tips. Wing length 2.6-3 mm. 
Male. Head. Ocellar setae very long, erect, divergent, 
inserted posterior to anterior ocellus; ocellar tubercle with 
some long setulae; postocellar seta stout and dark; upper 
postocular setae stout and dark, lower setae fine and slender; 
postgenal setae similar to lower postoculars. Face without 
setulae. Scape and pedicel slightly paler than postpedicel; 
scape short and slender, slightly longer than length of 
globular pedicel; postpedicel not greatly prolonged, more 
than 3x longer than scape, basal portion elongate-oval, 
slightly longer than slender, straight apical portion; arista-like 
stylus distinctly longer than postpedicel, concolorous with 
postpedicel. Proboscis stout and robust, extended beyond 
mid-length of fore coxa, directed posteriorly; palpus half- 
length of proboscis, clothed in long pale and dark setae; apex 
of palpus rounded; apical third of palpus somewhat flattened 
with dense pubescence. 
Thorax. Clothed in fine pruinescence; mesonotum brown, 
with postpronotal lobe, lateral margin and postalar ridge pale 
brown; pleura paler than notum, pale along sutures. Setae 
generally long and stout; 2-3 acrostichal setulae confined 
anterior to 1st dorsocentral seta, less than 0.5x length of dc; 
ppm with 1 seta and several short setulae; 1 long presut spal; 
5-6 uniserial dc, about subequal in length; 3 npl; 1 long psut 
spal and 1-2 finer setae; 1 pal seta; 1 pair of sctl, with 1-2 
pairs of finer outer marginal setae; disc of scutellum with 1-2 
pairs of long setae. Antepronotum with pair of pale setulae. 
Legs. Coxae and femora ventrally yellowish-brown; 
remaining segments increasingly darker apically. Inner 
anterior margin of fore coxa with some 15-20 dark 
variously lengthened and thickened spine-like setae, mostly 
concentrated apically; basal most seta longer than width 
of coxa. Anterior surface of mid and hind coxae with long 
brown setae. Legs clothed in very long setae as typical for 
genus, especially ventral faces. Fore femur straight, inflated 
(subequal in thickness to hind femur), with row of 2 stout 
anterior setae at apical fifth; 5-7 posterodorsal setae, stouter 
towards apex. Fore tibia with 2 anteroventral setae on apical 
third; 2 anterodorsal and 2 posterodorsal setae; 1 anterodorsal 
and 1 ventral preapical seta. Fore tarsomere 1 with 1 basal 
anteroventral and 1 preapical anterovental seta, more than 2x 
width of segment; 1 long basal ventral and 2 shorter ventral 
setae on basal half. Mid femur with row of 5-6 anterodorsal 
setae, stouter towards apex; 1 anterior, 1 dorsal and 1 
posterior seta on apical third; basal half with row of 4-5 stout 
posteroventral setae; apex with 1 anterior and 1 posterior 
preapical seta. Mid tibia with width reduced on ventral apical 
third, with row of 5 short spine-like setae; apex with short 
spur-like ventral seta; 1 anterodorsal and 1 posterodorsal 
seta near mid-length; 1 basal posterodorsal seta; apex with 
1 dorsal and 1 posterior seta. Mid tarsomere 1 with 1 long 
