154 SIREX SP. 

~~ 
It may be only an inch inside the sapwood or several inches. 
The imago cuts its way out by means of its powerful mandibles, 
making a circular hole through the wood and bark of a ¢ inch in 
diameter.? 
Locality from where reported. 
This insect was discovered by the writer in dead spruce 
trees in Tehri Garhwal, North-West Himalayas (Jaunsar Divi- 
sion), at an elevation of about 7,000 feet. 
Relations to the Forest. 
The injury done by this insect is entirely to the commercial 
value of the wood, the timber, when the larve are numerous, 
being riddled by their borings. (See Plate VII, fig. 1,e.) I 
have not ascertained how deep the borings go in large trees, 
but ina spruce of 3 feet diameter I found tunnels as deep as 
1 foot in from the outer edge of the sapwood, excluding the 
bark. The young larva soon after getting into the wood turns 
at an angle and bores up and down in the longitudinal axis of 
the tree, and a section of the wood of a badly attacked tree 
will show numerous galleries packed tightly with the wood 
chips. (See figure 1, e.) The tunnel is small in diameter at first 
but increases until, when the occupant is full grown, itis # inch 
in circumference. It is invariably very tortuous. 
Whilst the damage done to the timber by the larve is of 
itself very considerable, it is increased by the exit holes bored 
by the adults, and these let in moisture and fungi which soon 
ruin the rest of the sound timber. In PI. Vil, fig. 1, f, the larger 
holes and galleries in the bark are those of this insect. 
- Protection and Remedtes. 
We require to know exactly what species of trees are 
attacked by this insect before we can decide as to the damage 
— —_— 
1 Since this note went io press | have bred out adults of this species 
at Dehra Dun from wood brought down from Jaunsar in July and kept 
under supervision. A male issued on the 22nd September and a female on 
the 1st October. The male specimen is smaller than those obtained in the 
Himalayasin June and July. The female is the first specimen of that sex 
obtained. 1am of opinion that the lower elevation of Dehra (2,000 ft. only), 
and the consequently hotter climate, is the cause of these insects appearing 
at this time of the year. It is improbable, I think, that the mature insects 
ordinarily appear more than once in the year, #e.,in June and July, 


