106 



annually is very considerable. Insects cause stunted growth and deformity and at 

 times kill trees- outright. Insects are the cause of damage to trees right from the 

 nursery to the cutting or felling, and after the logs the converted into the finished 

 product, or even after it is placed in the finished article or structure. Insect- 

 destroyed timber furnishes fuel for forest fires which not only destroy the dead 

 timber, but injure and make susceptible to further insect attack, much of the green 

 living timber. It is well known that owing to the inroads of boring insects into 

 timber, deterioration and decay are more rapid than would otherwise be possible. 

 In every forest there is an ever present but inconspicuous army of insects which 

 live upon the bark, wood, foliage, seeds, and roots of the trees. 



Trees damaged by fire or scarred by falling limbs or trees of unhealthy growth 

 through unsuitability to soil, are urually the first to be attacked as they offer the 

 least resistance. 



In the following notes only the brief outline of a few species of local destruc- 

 tive forest insects is given, all unnecessary or minute details being avoided. To 

 enumerate the various pests of the forest would require a huge volume. 



Coleoptera Beetles.- — These are no doubt the greatest offenders in our foresti, 

 and of these the most numerous are the weevils (Curculionidae) , or commonly 

 known as the Snouted or Elephant Beetles. 



The Long Horned Beetles (Longicornes) are also a large and destructive 

 group. 



Some of the most dreaded of forest insects are contained in the Scolytidae. 



Wood Borers. 

 The Bostrycliidae, or Augur Beetles, are a well represented group. 



The Buprestidae, commonly known as Jewel Beetles, are very destructive to 

 various timbers. 



We will take these beetles in the order referred to. 



Weevils (Curculionidae) can readily be distinguished from other beetles by 

 the head which terminates in a snout. Their mode of attack is as varied as the 

 group itself; some attack only dying or dead trees, while others take the living 

 plants. The larvae burrow or tunnel the roots, trunk, twigs, or they may cause 

 galls or swellings to appear on the branches within which they live. The adult 

 beetles may be foliage, bark, bud, fruit nibblers, or feed upon stored foods. Some 

 adults have the power of flight, but many have lost that power. 



One of the commonest examples of a weevil is one known as the Grain Weevil 

 (Calandra oryzae). This insect lives and breeds in cereals or grains. A typical 

 tree-destroying weevil and one having a wide range over Australia is (Orthorrhinus 

 cylindrirostris) . The larvae of this beetle bore through the centre of the limbs and 

 pupate therein, causing, when numerous, the death of the tree. Not only forest 

 trees are attacked, but it has been found in our State attacking fruit and ornamen- 

 tal trees. 



The Longicorns or Long-horned Beetles (Cerambycidae) . — The most numerous 

 and characteristic are the members of the Genus (Phoracantha). The life histories 

 and general habits of all longicorn beetles are nearly identical. The perfect L>eetles 

 hide in the daytime under dead bark or resting on tree trunks. When captured 

 some of them produce a sharp rasping sound. They are nocturnal, that is, night 

 flying, coming out from their hiding places just about dusk. They are powerful 

 fliers and often attracted to lights. The colour is usually shiny black or reddish 

 brown and often mottled or blotched with pale yellow. The general form of these 

 beetles is elongate, antennae long and stout. The eggs are laid upon the bark in 

 cracks or under loose bark. The little larvae, so soon as they hatch, bore their way 

 through the bark where they remain feeding for some time upon the sap wood. 



