22 LIFE HISTORY OF TIMBKK MOTHS. 



this paper will be directed more particularly to the latter. Our 

 earlier Australian naturalists appear to have been acquainted with 

 only one species, and that the comparatively small but beautiful 

 Charagia lignivora, described by Lewin. It is only within quite 

 recent times that our species have been made known to entomo- 

 logical science, and principally through Scott, of New South 

 Wales. 



The caterpillars of the hepialids belonging to the genus 

 Charagia, all live in burrows, or in tunnels, in the wood of living 

 trees, sometimes far up the stem, sometimes penetrating a con- 

 siderable distance down into the root ; but in the latter case with 

 the opening into the chamber above ground, at the foot of the tree.. 

 Tho?ie of the genus Pit lus, &c., are entirely subterranean, feeding 

 upon roots. 



Beginning with the ova, we will now proceed to follow them 

 in their transformations. The eggs when extruded from the 

 ovipositor of the moth are of a pale yellow colour, but soon turn 

 of slaty gray hue ; they are round and about the size of a pin's 

 head. Many thousands must be contained in the abdominal- 

 cavity, for it is aliiiost entirely filled with them. Nearly all the 

 eggs laid are destroyed, probably almost at once falling a prey to 

 ants and siicli like insects. Those that escape destruction are- 

 possibly such as have fallen into cracks and crannies in the bark 

 of trees, where they remain until hatched out. Even of these 

 the larger proportion again are soon devoured. The remnant 

 that escape this fate at once commence boring into the bark, 

 and thence into the wood of the tree. Immediately they begin 

 to burrow into the wood the protective web is formed, and as 

 they increase in size so also is the web enlarged to meet their 

 necessities. The web is formed of silken threads interwoven 

 with bits of bark and woody matter, and is gradually strengthened 

 with the age of the insect until in many cases it becomes of a 

 tough felty consistence, one or two species even blocking up the- 

 intervening space with their dejectamenta, and causing the- 

 covering to assume the form of a large knot in the tree stem. 

 In the damp scrubs these soon become covered with moss, and 

 are not readily discernible. If one of these webs is torn away,, 

 the insect when all is quiet, will be observed to come partly out 



