SHOT-BORER BEETLES. 77 
thousand six hundred trees, we have already cut down one hundred, 
killed by the borer. In another field, about the same size, quite as 
many trees have been destroyed. We burn the trees directly we find 
a trace of the attack, but this does not seem to keep the enemy under, 
and it is difficult to know what to do.”’ 
The infestation was considered (just generally speaking) to be 
X. dispar ; but, wishing to have some special examination, I begged 
Mr. Wise to be kind enough to let me have some specimens, to which 
he replied on June 19th, mentioning that he was sorry to say that he 
could send me (practically) any quantity of infested stems of Plum 
trees showing Shot-borer Beetle attack, and that he then sent me the 
stem of a tree, and also a portion of the branch, and that he found as 
many in the branches as he did in the stem. 
To what extent dispar might be present in the trees, of course we 
cannot tell, but the specimens, which Mr. Wise furnished me with a 
most liberal supply of, showed that, though some small amount of the 
characteristic workings of dispar were to be found, the chief amount 
of workings were those of Xyleborus saxeseni, Ratz., then very fully 
occupied by attack chiefly in larval condition. Of these I took the 
following observations. 
On July 22nd, on splitting part of one of the above-mentioned 
pieces of Plum stem (of two and three-quarter inches in diameter) 
longitudinally, I found a horizontal tunnel running from the outside of 
about a quarter of an inch in length, on each side of which, beginning 
at the above distance (one-quarter inch) from the outside of the tree, 
a flat vertical cell was hollowed out, three-quarters of an inch long at 
the greatest height, and five-eighths in width. The shape of this flat 
chamber was somewhat squarish (see figure 3, p. 74), about two-thirds 
of it being above, and one-third below the mother gallery, of which 
some traces still remained, and which crossed the flat cell, and then 
was continued merely as a tunnel (a distinct gallery) for about three- 
eighths of an inch further, where it stopped, the extremity being filled 
with about half-a-dozen very young larve and a few eggs. 
The surface of the flat chamber (as seen in the side remaining 
after the other side had been cut away in the course of examination) 
was covered for the most part with a very thin coating of wax-like 
material, greyish in colour, and with a somewhat sweet scent, and the 
surface of the wood of the chamber, wherever it was visible, was 
certainly not of the black colour so noticeable in connection with the 
workings of the Xyleborus dispar. It was rather of a brown colour, 
and moist-looking appearance. 
This flat cell, or gnawed-out chamber, had only space enough 
between its two upright sides (see figure 4, p. 74) to accommodate the 
larve, which were for the most part apparently full-grown, and in 
