THE PEAR, 413 
observed suddenly to turn brown. In two or three days the 
eaves become quite black and dry, and the wood so shrivelled 
and hard as to be cut with difficulty with a knife. If the branch 
is allowed to remain, the disease sometimes extends a short dis: 
tance further down the stem, but, usually, not much further than 
the point where the insect had made his lodgment. The insect 
which causes this blight, was first discovered by the Hon. John 
Lowell, of Boston, in 1816, and was described by Professor 
Peck, under the name of Scolytus pyri. Jt is very minute, 
being scarcely one-tenth of an inch long; and it escapes from 
the branch almost as soon as, by the withering of the leaves, we 
are aware of its attack; hence, it is so rarely seen by careless 
observers. In the perfect state, it is a very small beetle, deep 
brown, with legs of a paler colour. Its thorax is short, convex, 
rough in front, and studded with erect bristles. The wing 
covers are marked with rows of punctured points, between which 
are also rows of bristles, and they appear cut off very obliquely 
behind. ; 
This insect deposits its egg some time in July or August, 
either behind, or below a bud. Whether the egg hatches at 
once, we are not aware, but the following spring, the small grub 
or larva grows through the sap wood or tender alburnum, be- 
ginning at the root of the bud, and burrows towards the centre 
of the stem. Around this centre or pith, it forms a circular 
passage, sometimes devouring it altogether. By thus perforat- 
ing, sawing off, or girdling, internally, a considerable portion of 
the vessels which convey the ascending sap, at the very period 
when the rapid growth of the leaves calls for the largest supply 
of fluid from the roots, the growth and the vitality of the branch 
are checked, and finally extinguished. The larva about this 
time, completes both its transformation, and its passage out, 
and, in the beetle form, emerges, with wings, into the air, to 
seek out new positions for layig ‘its eggs and continuing its 
species. The small passage where it makes its exit, may now 
more easily be discovered, below or by the side of the bud, re- 
sembling a hole bored with a needle or pin. 
Jt is well to remark here, that the attack of this blight izoect 
is not confined to the pear, but-in some parts of the country we 
have observed it preying upon the apple and the quince in the 
same manner. In the latter tree, the shoots that were girdled 
were shorter, and at the extremities of the branches only; not 
leading, therefore, to such serious consequences as in the pear. 
The ravages of the insect blight, we are inclined to think, do 
not extend much below the point where the insect has deposited 
its ego, a material point of difference from the frozen-sap blight 
which often poisons the system of the whole tree, if allowed to 
remain, or if, originally,,very extensive. 
he remedy for the engect blight is very distinct, It is that 
