72. PINE. 
rusty-colour in the legs; male blue-black, abdomen with margin of the 
third and the whole of the four following segments red; the hinder 
shanks and feet dilated and compressed. The size varies from about 
half an inch to an inch and a third, or an inch and a half in length, 
and from about three-quarters of an inch to a little above two inches 
in the spread of the wings; and in the case of specimens sent me, the 
variation in size appeared to coincide with whether the conditions of the 
maggots during their feeding-time had been favourable or otherwise. 
Amongst specimens from some buried wood I had a male just under 
half an inch long, and a female five-eighths of an inch long, including 
the ovipositor. 
Sirex maggots are soft and fleshy, whitish, and cylindrical, with 
smooth shining heads, furnished with strong square jaws, somewhat 
differing from each other. The three pairs of legs are short, and 
without marked divisions into joints; the prolegs beneath the abdomen 
are absent; and at the apex the abdomen is acute, ending in a sharp 
horny spine. The pupa resembles the perfect insect, lying soft and 
white, with the limbs laid along the breast and body. 
The female Sirex lays her eggs in various kinds of Fir, as Scotch 
Fir, Silver Fir, Spruce, and Larch, and is considered to choose for 
this purpose trees which are past their prime, or from some cause or 
other are wholly or locally in not full health. It has been stated that 
even if a small portion is injured the Sirex will choose this spot for 
egg-laying, and from this centre the grubs will spread in the wood. 
They are also stated to lay eggs in fallen trees, or in felled trunks left 
lying in the woods. 
The maggots bore large galleries in the solid timber, sometimes in 
sufficient number to riddle the trunks, and are full-grown in seven 
weeks, and the further change to the chrysalis takes place in the 
wood, but the date is considered to be uncertain,—it may take place 
immediately after full growth of the larva, or be delayed for an 
uncertain period. Consequently the imago (the perfect Sirex flies) 
may appear after delayed development from the most unexpected 
places, as from furniture or manufactured timber. 
PREVENTION AND Remepies.— Where attack is found to be prevalent 
in growing timber, the best treatment is to fell all that is found to be 
infested, and have it taken at once to the saw-pit and cut up and 
disposed of according to condition. Some parts would probably be 
free from attack, and might be used for any rough work, and other 
parts which were infested, and still had the insects in some stage alive 
within, should be burnt, or at least so treated that there was no danger 
of the infestation getting abroad. Felled trunks which are found to 
be infested should be similarly attended to, and also it should be borne 
