Page:A primer of forestry, with illustrations of the principal forest trees of Western Australia.djvu/114

108 The female lays her eggs in crevices in the bark. The larvæ are slender, flattened white grubs with small black jaws and flat head. They feed upon the sap wood until strong enough to bore into the solid timber, where they pupate. These beetles cause the death of many trees young and old.

The Bostrychidae or Augur Beetles.—These beetles are easily recognised by their curious cowled or hooded thorax, which comes down over the head. The body is long and adapted for burrowing. They are sometimes called Shot-hole Borers. Both native and cultivated trees are attacked. An introduced species named Rhizopertha dominica has obtained a footing in the State. It attacks stored foods, grain, leather and timber.

Plant Eating Beetles (Chrysomelidae).—These foliage-destroying beetles have a. regular thickened, more or less oval or rounded form, some of them not unlike Ladybirds, for which they are often mistaken. As a rule they rarely measure more than ^in. in length. The prevailing colours are red, yellow, or brown. They lay their spindle-shaped yellow eggs on the foliage or twigs of their food plant and when full grown the grubs crawl down and pupate in the soil beneath.

The Lepidoptera: Moths.—Amongst the moths several boring pests are to be found. These belong mostly to the family Hepialidae. The larvæ of these wood-boring moths are termed "bardies," and are relished as food by the natives.

The Genus Hepialus.—These large moths are generally found clinging to the tree trunks, where they are easily captured. In colour they vary from green, yellow, pink, and silvering shades. The moth lays her eggs upon the tree stem. The newly hatched caterpillar bores into the centre of the branch and then makes a vertical shaft which may be several feet long wherein it feeds and pupates. The moth develops from the pupa in the summer and escapes from the pupal case, which is frequently found projecting from the hole in the trunk or root after the moth has emerged. The females of some species lay thousands of tiny eggs.

The Genus Cossidae or Goat Moths.—The caterpillars from these moths feed in the stems of trees. The short, naked larvæ tunnel round the bark until nearly full grown, when they bore into the wood and pupate in cocoons. The moths are of a delicate slate colour and finely marbled with black lines.

The Genus (Pielus) contains some large brownish moths with very hairy legs. (Pielus haylinatus) is one of our commonest species. It is of a general chocolate brown tint with an irregular silvery white stripe and dark lines running through the centre of the fore wings. The hind pair are generally brown with the basal portion light pinkish shade. The caterpillars feed in the roots and trunks of several species of Acacias. The empty pupal cases may be seen sticking out of the roots or tree trunks.

Another group of moths which cause a lot of damage are the Cryptophaginae. These slender caterpillars live in shallow chambers or short tunnels in the branches of trees. They cover the entrance of their burrow with a screen of loose silken web interwoven with gnawed bark and droppings. Resting during the day, they come out at night, and biting off some of the leaves drag them down into the burrow. When full grown they pupate in their burrows. One of these moths (Cryptophaga unipunctata) (Cherry borer), has taken a fancy to cherry and plum trees—the larva bores into the branch or trunk of the tree causing gumming and often the death of limbs. There are many other species of Lepidoptera whose larvæ feed upon the foliage, bark and seeds of forest trees, but space will not permit their inclusion.

Orthoptera (Termitidae): White Ants.—These insects are amongst the most destructive of our forest pests, attacking almost all kinds of timber. They are not ants, although commonly called such, having no relationship whatever with the true ants. We have a great number of species, many of which have never yet been described or named. Were it possible to estimate the direct and indirect loss due