20 
DAVID I. CARTWRIGHT 
Female. (Fig. 17.) Black; wing venation as for 
male. Anterior w'ing length 5.6-8.6 mm (x = 7.2, 
n = 12). Female genitalia with eighth tergite and 
stemite entirely fused, apical margin fringed 
laterally with long setae. Ninth tergite arched; 
sternite with two triangular sclerites, their inner 
margins touching at base. Tenth segment with a 
pair of short, single- segmented cerci. 
Chimarra australica (Ulmer) 
Figs 10, 11, 14-16, 18 
Chimarra australica Ulmer 1916: 3-5, figs 3-6.— 
Mosely & Kimmins 1953: 399-402, fig. 274. 
Diagnosis 
Final instar larva. (Figs 10,11.) Length 8.3-10.4 
mm (x = 9.2 mm, n = 12). Head length about 
1.5 x width. Frontoclypeal notch with flattened 
base (Fig. 10). Only left mandible with projec¬ 
tion on mesal margin near middle (Fig. 11). 
Pupa. (Figs 14-16.) Length 5.6-6.5 mm (x = 
6.0, n = 2). Mandibles with bifid, subapical pro¬ 
cess (Fig. 14), slightly more conspicuous than in 
C. monticola. Anterior hook plates on abdomi¬ 
nal segment 3 with 2 or 3 teeth, segment 4 with 3 
or 4 teeth (Fig. 15); generally with fewer teeth on 
each hook plate than on corresponding plate of 
C. monticola. 
Female. (Fig. 18.) Black; wing venation as for 
male. Anterior wing length 5.3-6.4 mm (x = 5.7 
mm, n = 15). Female genitalia with eighth ter¬ 
gite and sternite entirely fused, apical margin 
fringed laterally with long setae. Ninth tergite 
arched; sternite with two sub-trapezoidal scler¬ 
ites, their inner margins touching at base. Tenth 
segment with a pair of short, single- segmented 
cerci. 
DISTRIBUTION IN VICTORIA 
C. monticola is widely distributed in eastern 
Victoria, with records including high altitude 
streams on the Bogong High Plains and around 
Mount Buller. The only record from west of Mel¬ 
bourne is from the Otway Ranges (Fig. 19). 
C. australica is also widespread in eastern Vic¬ 
toria but there are no records from high altitude 
streams, and the species is generally found in 
warmer streams than C. monticola. In western 
Victoria, C. australica has been recorded from 
the Wannon River, Lai Lai Falls and the Otway 
Ranges (Fig. 20). 
Extensive collecting in the Yarra River system 
over several years has provided reasonably com¬ 
plete distributional data for that area (Fig. 21). 
Chimarra has not been recorded from first or 
second order streams, occurs in some third order 
streams, but appears to be more common in 
larger streams of order four or higher. C. aus¬ 
tralica has been collected from the mainstream 
of the Yarra River and Starvation Creek at sev¬ 
eral sites below a small weir. C. tnonticola is 
widely distributed in larger tributaries but has 
been recorded at four sites in the Yarra River 
mainstream where the two species overlap. C. 
monticola is, however, usually quite rare in 
mainstream samples where C. australica is 
always dominant. 
BIOLOGY 
Headwidths of larval instars of both species col¬ 
lected from the Yarra River at Peninsula Road 
during 1979-80, together with those of C. mon¬ 
ticola collected from the O'Shannassy River in 
1975-77 (from Dean & Cartwright 1987), are 
presented in Table 1. Instars 1 and 2 from the 
Yarra River could not be identified positively 
but, given the dominance of C. australica in later 
instars, most of the early instars probably also 
belonged to that species. 
1 
2 
INSTAR 
3 
4 
5 
O’Shannassy R. 
C. monticola 
— 
0.26-0.28 
0.38-0.50 
0.58-0.72 
0.82-1.12 
Yarra R. 
C. monticola 
C. australica 
Chimarra sp. 
0.14 
0.24-0.26 
0.46-0.48 
0.34-0.46 
0.58-0.70 
0.48-0.66 
0.80-1.00 
0.70-0.92 
Table 1. Headwidth range (mm) of larval instars of Chimarra monticola Kimmins from the O’Shannassy R^ r 
(Dean & Cartwright 1987) and C. monticola and C. australica (Ulmer) from the Yarra River 1979-80. 
