December, 1952 THE SOUTH AUSTRALIAN NATURALIST 
Twenty-one 
DESERT INSECTS 
G. F. Gross, Assist. Entomologist, S.A. Museum. 
When the term desert is men- 
tioned, many people will probably 
visualize long rows of parallel sand- 
ridges without a trace of vegeta- 
tion, others will al ow this vision 
to include perhaps an occasional 
cactus or similar plant. Areas such 
as this are only met with 
occasionally in the large deserts of 
the world, the American deserts 
are fairly lavishly equipped with 
cacti and leguminous plants, and 
similar conditions obtain in the 
deserts of South Africa and Asia 
Minor. Even our own Arunta or 
Simpson Deserts and the Western 
Desert are fairly well clothed with 
porcupine grass ( Triodia spp.) and 
sandhill cane grass ( Spinifex para- 
doxus). 
However, so far as insects are 
concerned the so called “arid” 
regions outside of the 8 in. annual 
rainfall line, provide an environ- 
ment which most of the time is 
every bit as harsh as that of the 
Australian deserts listed above, 
and as the communities of the two 
do not differ essentially, these arid 
regions have also been included in 
this discussion. But we must re- 
member that when rain does fall 
in the arid regions, especially those 
bordering on the maUee, then their 
insect communities are temporarily 
strongly augmented by many 
species with a distinctly “wetter” 
or more Southern look. This phase 
of the insect life of the arid en- 
vironments however is not dealt 
with here. 
Actually the insects of the desert 
are not necessarily subjected to the 
full rigors of their environment as 
perhaps a person walking through 
would think. For example, many 
of the insects in these regions 
(bugs, certain beetles, thrips, 
witchety grubs, etc.) are plant 
feeders, and spend their time cosily 
in the shade amongst the leaves 
or inside the stems or roots, 
with the (for them) unlimited 
water supply of their hosts at their 
disposal, others spend most of their 
life permanently underground, e.g. 
chafers, cicadas, ant-lions (all as 
“grubs”). Others seen walking on 
the blazing surface like ants and 
certain wasps, can retreat under- 
ground, others like grasshoppers, 
stick insects, certain flies and wasps 
can retreat into the cool of a handy 
bush. Still another group are noc- 
turnal, spending their days under 
stones (beetles of the Cubicorrhyn- 
chus group, ants and the occasional 
silver-fish), or in shady bushes 
(cockroaches, some stick insects). 
Therefore collecting at night with 
a light yields a great variety of in- 
sects scarcely seen during the day, 
e.g. Rutherglen bug, (Nysius vini- 
lor ), various Neuroptera and chafer 
beetles. 
We can say very little at this 
stage about the individual habits 
and preferences, the distribution 
and community structure of the 
insects of the “desert” (or for that 
matter any other region of South 
Australia). 
We are sadly in need of very 
much larger collections than we 
have at present. Each insect caught, 
preferably with exact data recorded 
on the place and position of cap- 
ture (e.g. 5 miles north of Hawker, 
on underside of leaf of bullock 
bush, 5 feet above ground in the 
