Insects of Australia

The insect fauna of Australia is as remarkable and distinct in its peculiarities as the flora, and for the same reason — its isolated position from the rest of the world.

Naturally, Australin fauna, particularly insects, have had to adapt to extremes, and we find them with a variety of peculiar habits that are not found in more normal countries.

Ants, Formicidae, swarm in the interior’s driest areas, and flies of all kinds, including blow flies, blue bottle flies, and small house flies, are a constant pest throughout the summer.

All of our coastal scrubs are abundant in flowering shrubs, which serve as food or a hunting ground for a large insect population.

The larger continental areas, as well as the configuration of the continent. If we remove the eastern mountain range that runs north and south from Cape York to Gippsland, we find an enormous tract of almost level country with hardly a river of any size except the Murray and its tributaries, covered in thick scrub or open forest, great flat unbroken plains in the south; rolling downs towards the north; sand-hills, and low timbered ranges in the interior. It is half the year without any permanent water for hundreds of miles at a time; scorched with a blazing sun and fierce hot winds in summer, bleak and cold in winter. Yet there is no desert country in the strict sense of the word in the most arid portion; for given a good fall of rain, the country, apparently parched beyond recovery, soon puts on a coat of green, wild flowers sprout out, insects and little creatures of all kinds emerge from their hiding places, and birds appear as if by magic.

Australian fauna is extremely rich in gall-producing insects in many different orders; there are about 50 different species of coccids that form well defined galls upon their host plants, yet the only record of a gall-making coccid outside Australia is a single species in Mexico. Thripidae produce a large number of galls in the leaves or flower buds of our native shrubs, while Psyllidae, Diptera, and Hymenoptera produce a large number of galls.

The flower wasps, Thynnidae, (in which the males are large and handsome with well developed wings, but the females are diminutive and wingless,) have several hundred described species; the only other countries where they are represented are the west coast of South America and a few in the Pacific Islands. In the interior, there are more allied ant-like Mutillidae with their windless females.

Though our country is abundant in Sawflies, Tenthredinidae, they all belong to genera unique to Australia; members of the typical genus Cimher, which extends its range as far east as Japan, do not reach us.

The low stunted flowering shrubs that cover large patches of both the eastern and western coasts support a large number of Jewel-beetles, Genus Stigmodera, which are also unique to this continent. We appear to have few forms that are related to North or South America; our affinities are with Africa and the Malay Peninsula; insects with long-lasting flight, such as the Orthoptera, are found here and are identical to species found in Africa and Asia.

Many insects found in the eastern coastal districts have a very limited range; however, on the western watershed, others can be found ranging all the way to the Indian Ocean.