THE PEAR. 413 



observed suddenly to turn brown. In two or three days the 

 leaves 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. It is very minute, 

 being scarcely one-tenth of an inch long ; and it escapes from 

 the branch ahiiost 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 ^^^g some time in July or August, 

 either behind, or below a bud. Whether the q^q^ 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 de\'ouring it altogether. By thus perforat- 

 ing, sawing oft', 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 laying 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. 



It is well to remark here, that the attack of this blight insect 

 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 egg, a material point of difterence from the frozen-sap blight 

 which often poisons the system of the whole tree, if allowed to 

 remain, or if, originally, very extensive. 



The remedy for the insect blight is very distinct. It is that 



