The Blight in Pear Trees. 19 



had been forwarded by Governor Lincoln. The letter was 

 published in the Neiv England Farmer^ Vol. Y. No. 1, on 

 2Sth July, 1826. 



These are extracts : — 



" In the latter end of June, or in July, one or more limbs 

 of a tree in the fullest vigor, with fruit often upon them, and 

 with shoots of the same year, perhaps IS inches long, full of 

 sap, suddenly appears blasted ; in three days, the wood be- 

 comes dry and hard, and the fruit itself is desiccated, and so 

 hard as to be cut with difficulty with a knife. The effect, in 

 short, is precisely the same as if you had sawed off the limb 

 and thrown it on the wood-pile, and so it ought to be, for, in 

 effect, it has been sawed off by the teeth, or rather instru- 

 ments, of a minute insect. 



" The partial effect in a vigorous tree led me to suspect it 

 to be the work of an insect. As I had detected the insect 

 which is the enemy of the White Pine, and which often entirely 

 destroys the beauty and value of that tree, in the forest, and 

 had succeeded in extirpating it, or materially checking its dep- 

 redations, in my own grounds, I was led to hope that the 

 blast in the pear tree might also be occasioned by a wood- 

 eating insect, and I was the more encouraged to hope this, 

 since the case was so rare, as I may say, so entirely anom- 

 alous, of a tree being in a perishing state in some parts, and 

 in high health in others. 



" I cut off one of the diseased limbs, and spent many hours 

 before I detected the cause of the evil. The insect is so small, 

 its place of operation so concealed, (no external hole or swell- 

 ing to lead you to suspect it,) that it requires much care to 

 find it. Yet, when discovered, the injury was quite suffi- 

 cient to produce all the effect ; he had eaten from the root of 

 a bud, behind which, probably, the egg was deposited, fol- 

 lowing the course of the eye of the bud into the pith which 

 he had consumed, together with all the heart- wood. He had 

 then gone into the chrysalis state, in the scene of his depre- 

 dations, and was in the perfect state when I found him. 



" I carried the branch and insect to Professor Peck, who 

 soon ascertained that it was the perfect larva, of which the 

 genus was known, although this species was new." This 

 was the Scolytus Pyri. 



