Twenty two 
THE SOUTH AUSTRALIAN NATURALIST December, 1952 
shade; or under stone; or in soil; 
or on bark 2 it. 6 in. up a red gum; 
etc.), together with the nature of 
the environment (imilga scrub, red 
gum creek, Atriplex vesicarum 
steppe, etc.), altitude, wet and dry 
bulb temperatures, wind, weather, 
time and date, is urgently needed. 
I intend now to discuss a broad 
classification of the environments 
of the desert insects, naming tenta- 
tively only those formations which 
are very distinct as regards their in- 
sect communities and known per- 
sonally, and retaining the recog- 
nised botanical association group- 
ings for complex environments or 
ones which shade into each other 
in a patchwork pattern, such as 
occurs in the Northern Flinders 
Ranges. What little we do know 
about the insect species present is 
included in the relevant section. As 
a major separation we might use 
soil type, although it must be 
stressed that it is by no means 
absolute. For example one can find 
often on sandhills associations of 
mulga ( Acacia aneura and related 
species), or black oak (Casuarina 
lepidophloia), yet in places associa- 
tions of each of these species can 
occur on clay soils or talus slopes. 
Sandy Formations (soft country). 
Almost invariably stones with 
their attendant insects, are absent, 
but one finds here those insects 
more specially able to burrow 
(various wasps, including the bem- 
becid wasp [Bern hex variabilis], 
chafers, etc.) and of course the 
usual plant feeders. Many of the 
shrubs of this environment have a 
characteristic dome shape with 
dense outer covering. The parallel 
sand-ridges of the Arunta, the 
Great Western or Victoria Deserts 
with iheir covering of porcupine 
grass and in the former cane grass, 
fall into this category as does the 
Schoberian (a formation of nitre 
bush, Nitraria Schoberi, with 
occasional needle bushes -(Hakea 
spp. and Cassia desolata and C. 
eremophila), south of Lake Eyre 
North ancl north of Muloorina 
Station. Characteristic insects of 
this latter formation are a silver- 
fish (Acrotelsella sp.) the ant 
Pheidole tasmaniensis , the thynnid 
wasp Thynnus zonatus, and prcda- 
; tory wasps of the Larridae, 
| Sphecidae and Psammocharidae. 
Along the shores of Lake Eyre the 
Cicindelid beetle Megacephala 
australis is common. 
Many sandhill formations are 
dominated by mulga, for example 
between Lake Torrens and the 
section of the North-South Rail- 
way line between Mern Merna 
and Parachilna, others by black 
oak, as the south shores of Lake 
Torrens and in the east of the 
State, while south of Lake Frome 
is a formation dominated by Hakea 
lencoptera. In the mulga formation 
the mulga thrip Plaeothrips tepperi 
is present, and near local swamps 
the Rutherglen bug ancl large 
Specie! wasps are found. The 
“Casuarina mind” (Genus and 
species unknown) and the lerp in- 
sect Trioza rasuarinae probably 
occur in the black oak regions. 
Often this country supports liter- 
ally myriads of bush fly ( Musca 
vetutissima ). 
Loam Soil Formations. Here 
again stones are rarely present and 
curiously enough the burrowing 
insects seem to be somewhat 
reduced. The Sow deni an is 
a formation dominated by the 
myall (Acacia Sowdenii) with 
Atriplex vesicarum, A. stipitatum 
and the two blue bushes Kochi a 
sedifolia and K. pyramidita and 
occasionally sandalwoods (Myop- 
