86 
PlNE. 
half an inch long, and a female five-eighths of an inch long, including 
the ovipositor. 
The habits of these two kinds of Sirex appear to he almost exactly 
similar. The females pierce into the bark of the Larch, Silver Fir, or 
other kind of Conifer that they may attack (standing or felled, as the 
case may be), and with their strong ovipositors deposit their eggs, one 
at a time, in the soft wood immediately beneath. 
The maggots are whitish, soft, and cylindrical, with scaly heads 
furnished with strong jaws. The three pairs of feet are very small, 
and at the rounded tail-extremity (above) there is a blunt point or 
spine; they feed in the solid timber, causing great injury by their 
large borings. The maggot of the Giant Sirex is from one and a half 
to two inches long when full-grown, and is considered to be full-grown 
in about seven weeks. 
The chrysalis is like the perfect insect in form, but white and soft, 
with the limbs laid along beneath the breast and body until complete 
development. After a time the perfect insect comes out of the tree or 
log, or it may be the plank or piece of furniture, in the wood of which 
it has fed, but the time which may elapse between the maggot being 
fully grown and the Sirex making its appearance seems to be quite 
uncertain. 
The following notes by Mr. W. Hodgson, A.L.S., of Workington, 
Cumberland, show the great amount of damage which can be caused 
by Sirex-attack—in this case that of the Common Steel-blue Sirex:— 
Mr. Hodgson mentioned that whilst walking through the grounds 
of Mrs. Robertson Walker, of Gilgarron, about five miles inland from 
Whitehaven, he was struck by the failed condition of the fine Silver 
Fir trees, and, on asking the reason:—“ The woodman stated that the 
injury was due to the ravages of a grub which perforated the trunks of 
the trees so extensively, especially in the upper part, as to cause the 
mischief. This was only found out recently, when some of the dead 
trees were felled and taken to the saw-mill on the estate. We examined 
some of the fallen trees, and their condition supported entirely the 
woodman’s view of the case.” 
“ The grub which was found at work proved to be that of a Sirex, 
and later on, specimens of the perfect insect being found, were sent to 
Mr. S. L. Mosley, of the Beaumont Park Museum, Huddersfield, by 
whom they were identified as being the Sirex juvencus (the “ Common” 
or “ Steel-blue” Sirex. —Ed.). The number of Silver Firs on the 
grounds is slightly in excess of forty trees, of over seventy years’ 
growth, varying in bulk from twenty to forty cubic feet per tree. This 
will give on the whole a trifle over 1200 cubic feet of timber irretrievably 
damaged, which, estimated at sixpence per foot, represents a loss of 
£30 in money value, to say nothing of the injury done to the appear- 
* 
