BY K. ILLIDGE. 
31 
been placed, and so reared them without affecting the normal 
size of the imago. It is therefore necessary for success in secur- 
ing the perfect insects to obtain their caterpillars when full-fed 
or nearly so, or else when they have already passed to the 
chrysalis state. They seal themselves in the burrow when about 
to change, and some of them do this very artfully. One or two 
species spur out a spout-like web of silk and bits of bark mixed, 
which looks like a little piece of dead or decaymg stick ; another 
species spins a web flush with the bark and so exactly like it 
that it is almost impossible for it to be distinguished. Others 
again simply spin a strong web inside and across the opening 
of the tunnel, whilst some content themselves with only 
partially closing the hole with a curved piece of brown horn-like 
substance, the nature of which is unknown to me, and occasion- 
ally the opening is quite unprotected. Just before pupation 
takes place the external covering is usually torn away, and a 
very careful search is then necessary to secure examples. They 
remain in the pupa state for a very variable period, some emerg- 
ing in a fortnight or three weeks and others after as many 
months. As a rule the trees are not seriously damaged by their 
burrows, though odd branches become sickly and die. The 
large Maroga unixmnctana, however, is an exception, for it feeds 
on the bark and frequently eats completely round the stem, thus 
ringbarking the tree. Dogwood and wattle trees may often be 
found quite dead above from this cause. On the moth emerging 
the hole soon commences to close up and no external trace of it 
is left after a little time, except perhaps a slight scar which also 
in course of time disappears. The abovemeiitioned M. unipunc- 
tana is said to be very destructive in Victoria to fruit trees, but I 
have not noticed its appearance here in such trees, possibly 
because my experience is limited to my own garden. I have, 
however, noted a large species amongst leguminous trees in the 
Botanic Gardens, one of which, in front of the curator’s house,, 
has been utterly destroyed by them. The pup® of the species 
of Xyloryctid® are usually cylindrical, conical ac the hinder 
extremity and rather flattened towards the head, with one 
notable exception. In the insect affording it the chrysalis has 
a strange bifurcated projection in front, which appears to be for 
the purpose of cutting, auger-like, a way through the very thick 
