Records of the Western Australian Museum 17: 181-189 (1995). 
Notes on the Corixidae and Notonectidae (Hemiptera: Heteroptera) 
of southern Western Australia 
I. Lansbury 
Hope Entomological Collections, Oxford University Museum, Parks Road, Oxford, 0X1 3PW, England 
Abstract - The nektonic water-bugs (Corixidae and Notonectidae) collected 
during recent surveys in southern Western Australia are listed. Anisops bay hi 
sp. nov. is described from a number of widely distributed localities. The 
variation between the forms of some Anisops species recorded is commented 
on and brief notes on the extra-limital distribution of the water-bugs within 
Australia are given. 
INTRODUCTION 
The fauna of temporary pools on granite 
outcrops in the Northcliffe region and other widely 
distributed localities were sampled in 1977 (Bayly 
1982). Further collections were made by Bayly 
during the winter of 1990 and those were in part 
made from habitats not on granite rock strata 
(Bayly 1992a). For data on rainfall pattern and 
physico-chemical parameters of pools on granite 
see Bayly (1982). Some general features of 
temporary pools on granite inselbergs in southern 
Western Australia are discussed by Bayly (1992b). 
Other samples collected from habitats on the Swan 
Coastal Plain are included as the new species 
Anisops baylii was found by F. Cheal to occur in 
this region as well as in several other widely 
distributed localities in the Bayly samples. 
The water-bug fauna of southern western 
Australia has some similarities with those found in 
south eastern Australia. The number of species in 
the genera recorded from both regions as 
compared with the total number of described 
Australian species are shown in Table 1. 
Three endemic species were identified: Paranisops 
endymion (Kirkaldy), Notonecta handlirschi Kirkaldy 
(a specimen of this species studied from the Swan 
Coastal Plain leg F. Cheal) and Sigara mullaka 
Lansbury. 
The data extracted from Bayly's samples tends to 
suggest that the water-bug fauna of southern 
Western Australia is depauperate compared with 
that of south eastern Australia. This may reflect the 
type of habitats sampled by Bayly and a broader 
range of sampling would increase the overall 
species diversity. Bayly sampled 49 habitats in 
1977, some were sampled several times, water- 
bugs were found in 18. In 1990, 86 habitats 
sampled (two previously sampled in 1977) and 
water-bugs were found in 27 samples. 
The species diversity of the two series of Bayly's 
samples do not differ significantly allowing for the 
greater number of habitats sampled in 1990. A 
small number of Anisops females could not be 
identified and are excluded from the study. 
Especially noticeable is the lack of Sigara species 
other than S. mullaka. Samples from Victoria and 
South Australia collected by the author frequently 
included two species, S. truncatipala (Flale) and S. 
sublaevifrons (Hale), occasionally three species with 
S. australis (Fieber). 
There is some evidence that at least two Anisops 
species e.g., A. thienemanni Lundblad recorded 
from many habitats and A. elstoni Brooks recorded 
from several localities in southwestern Australia 
differ in some features (size and secondary sexual 
characters) from forms recorded from other 
regions in Australia. 
The species listed or mentioned other than N. 
handliirschi are the most commonly encountered in 
southern Western Australia. The list only 
represents the species in the Bayly samples and 
small series from the Swan Coastal Plain, F. Cheal. 
MATERIAL AND METHODS 
The type series of Anisops baylii from the Swan 
Coastal Plain will be deposited in the Western 
Australian Museum, Perth (WAM). Some of the 
Bayly material will be placed in the Museum of 
Victoria, Melbourne (NMV) with voucher 
specimens retained in Oxford (OUM). All the 
material is alcohol-preserved. Figures were drawn 
from either slide mounted preparations or from 
temporarily dried material which was then 
returned to alcohol. 
