20 
Records of the Australian Museum (2016) Vol. 68 
Hormopeza 
CD 
H 
cn 
o 
H-H 
tt 
H 
H 
- aptera AU 
- unguicula AU 
- akatarawa NZ 
- milleri NZ 
■f- clarae NZ 
05 
I- paniculata NZ 
-vj 
f- vockerothi NZ 
-- tasmanica AU 
*-H— wardi NZ 
05 <D — 
■— curicoa CH 
^ o 
Figure 29. One of four most parsimonious cladograms of Hydropeza 
relationships produced by analysis of the data matrix (Table 1) (tree 
length = 40). Character distributions shown by black hash marks for 
uniquely derived states and grey hash marks for homoplasious states. 
AU, Australia; CH, Chile; NZ, New Zealand. 
curvata AU 
divaricata AU 
angulata AU 
intricata AU 
cornuta AU 
queenslandensis AU 
(Fig. 30) and diversified across former Gondwanan 
continents following the separation of southern South 
America from Africa in the Early Cretaceous. Therefore the 
origin of the genus is hypothesized to date from this period or 
earlier. The geographic patterns in Hydropeza are similarly 
as complex as among the Ceratomerinae (Sinclair, 2010), 
which also include species adapted to a winter flight period. 
In Australia, Hydropeza is presently known only from 
Tasmania and northern Queensland (Wet Tropics) (Fig. 
30). A similar widely disjunct distribution is also recorded 
for the genus Apterodromia Oldroyd (Hybotidae), although 
also recorded from Western Australia (Sinclair & Cumming, 
2000). The aquatic fly fauna of eastern Australia is generally 
well surveyed using a variety of trapping methods and the 
disjunct distribution of the genus is possibly not an artefact 
due to lack of collecting. The absence of the genus from 
Victoria, New South Wales and southeastern Queensland 
cannot be explained, especially since a wide range of habitats 
that are suitable to Hydropeza are present in this region. 
Sampling surface flies with dip nets may produce additional 
samples from these other regions. 
It is rather remarkable that there are five variously 
sympatric species on Mt. Lewis above 700 m, while only 
six species are known from the entire Wet Tropics. However, 
the specimens are all mostly from a single collecting trip, 
and concentrated efforts elsewhere in this region will likely 
expand species ranges. High endemism was also found 
among flightless insects in the Carbine Uplands, which 
includes Mt. Lewis (Yeates et al., 2002). 
Table 1. Data matrix for Hydropeza, listing 17 terminal 
taxa and 22 characters used in the analysis. See Table 2 for 
character descriptions. Character states were scored 0-3, 
en-dash for inapplicable data and ? for unknown data. 
Characters 
Taxa 0000000001 1111111112 22 
1234567890 
1234567890 
12 
Hydropeza akatarawa 
0101011100 
0000011200 
00 
H. angulata 
0001111101 
1110110200 
03 
H. aptera 
000111—0 
0000000210 
00 
H. clarae 
0001001110 
1100110200 
01 
H. cornuta 
0001111101 
1111110200 
12 
H. curicoa 
0011011101 
1100110200 
12 
H. curvata 
0001111101 
1110110200 
12 
H. divaricata 
0001111101 
1110110200 
12 
H. intricata 
0001111101 
1111110200 
03 
H. milleri 
1001001100 
1100000100 
00 
H. paniculata 
0001011110 
1100111200 
01 
H. queenslandensis 
0001111101 
0011110200 
12 
H. tasmanica 
0011011101 
1100110211 
01 
H. unguicula 
0001111100 
0000110200 
0? 
H. vockerothi 
0001011110 
0100111200 
01 
H. wardi 
0011001111 
1100110211 
01 
Hormopeza 
0000100000 
0000000000 
00 
