
SIREX SP. 153 
last segment of the body and the augur exposed. ‘The abdo- 
men is smooth and is a brilliant metallic blue verging to black 
on the under surface. Ovipositor consisting of three portions 
and black in colour, 11th inch in length. Length 1,%;th inch 
to end of ovipositor, and 11th inch to end of augur. (See Pl 
VI, fig. 1, d.) 
Life History. 
This insect appears on the wing about the middle of June, 
perhaps earlier. It attacks spruce trees, and the writer has 
found it at the end of the month both in the wood and flying 
about in the forest. The insect is to be found in all its stages 
of larva, pupa, and imago at this period. 
The eggs are laid by the female in the wood of dead spruce 
trees (I think it possible that blue pine and perhaps other trees 
are also attacked by it or an allied species) some time during 
July. The larvz on hatching out are small yellowish grubs and 
bore straight into the wood, in which they remain feeding and 
tunnelling for over a year. The latter is, I think, probable, since 
I have found small larve and large full-grown ones together in 
the same tree. The length of time spent in the pupal stage is 
not at present known. Pupe have been found in the tunnels in 
the middle of June and on into July, and it is probable that the 
adults issue at intervals for several weeks until the burst of the 
monsoon. On becoming mature the Szrex bores its way out of 
the wood to the outside, the tunnel being either horizontal or 
at an angle, depending apparently on the position of the larva 
when it ceased feeding. When this latter occurs the head of 
the larva is generally, if not always, pointing in the direction of 
the outside of the tree, and not facing inwards, but as often as 
not this tunnel is at an upward angle. The imago will then 
bore in a line straight for the outside, but the tunnel may be 
curved upwards, Ihave never found imago-tunnels pointing 
downwards. The larval gallery is always tightly packed with 
dry wood chips, so that during its feeding operations it is always 
moving forward, and when full fed the only free part of its 
gallery is the space it is lying in, The depth within the tree 
at which it changes into the pupal condition appears to vary. 
M 2 
