0’ 
SHOT BORER. 
125 
stop the course of the sap; and consequently the destruction of the 
small trees (which are preferred for boring purposes by the beetle) is 
rapid and complete. Full details were given in my preceding Report. 
But it may he desirable to repeat that the reason of the singularly 
rapid and complete destruction of the stem of young trees attacked by 
these beetles was plainly shown on laying open their tunnels. In the 
specimens of these from Toddington which I examined (figured life 
size at p. 124), I found that the injury began by a small hole like a 
shot-hole being bored in the side of the attacked stem, from which a 
tunnel ran to the pith, and a branch about the eighth of an inch across 
ran horizontally about half or two-thirds round the stem. Sometimes 
this tunnel was about midway between the outside and the centre, 
but in one instance quite at the outside of the wood. From these 
horizontal borings, other borings were taken straight up and down the 
stem; these might be certainly as many as four (perhaps more in one 
stem), and were from half an inch to upwards of an inch and a half 
long; and of these tunnels (in the pieces of stem I examined) one ran 
along the pith, which was completely cleared away. The great injury 
caused by these galleries fully accounted for the death of the stem. 
The great peculiarity of these insects is the difference in shape and 
size between the male and female (the disparity , from which the beetle 
takes its name of dispar). The female is about the eighth of an inch 
long, narrow and cylindrical, with the thorax (the fore body) large 
in proportion, and raised in the middle so as to make a kind of hump. 
The male is only about two-thirds of the length of the female, and 
much wider in proportion, and the back is flatter. 
As a method of prevention, cutting down the attacked trees and 
burning them when the infestation is noticable is most strongly to be 
recommended. It is no waste, for in many cases the attack is com¬ 
pletely and rapidly fatal, and if the plan is carried out before the female 
beetles (which may be found in such numbers as almost to fill the 
galleries towards the end of summer or autumn) have flown, it is very 
effectual. 
In the case of the attack of this Xyleborus dispar, or Shot Borer 
Beetle, at Toddington, all the trees that were found to be affected were 
cut down and burnt; and this year Mr. C. D. Wise, the manager of 
the Toddington Fruit Grounds, notes that only one case of attack has 
been found. 
