78 INSECTS INJURIOUS TO VEGETATION. 



passages, parallel to each other, between the bark and the 

 wood. They are much less common in the New England than 

 in the Middle and Southern States, where they abound in the 

 yellow pines. 



Another bark-beetle is found here, closely resembling the 

 preceding, from which it differs chiefly in the inferiority of its 

 size, being but three twentieths of an inch in length, and in 

 having only three or four teeth at the outer extremity of each 

 wing-cover. It is the Tomicus Pini of Mr. Say. The grubs 

 of this insect are very injurious to pine-trees. I have found 

 them under the bark of the white and pitch pine, and they 

 have also been discovered in the larch. The beetles appear 

 during the month of August. 



There is another small bark-beetle, the Tomicus liminaris of 

 my Catalogue, which has been found, in great numbers, by 

 Miss Morris, under the bark of peach-trees, affected with the 

 disease called the yelloivs, and hence supposed by her to be 

 connected with this malady.* I have found it under the bark 

 of a diseased elm ; but have nothing more to offer, from my 

 own observations, concerning its history, except that it com- 

 pletes its transformations in August and September. It is of 

 a dark brown color; the thorax is punctured, and the wing- 

 eovers are marked with deeply punctured furrows, and are 

 beset with short hairs. It does not average one tenth of an 

 inch in length. 



The pear-tree in New England has been found to be subject 

 to a peculiar malady, which shows itself during midsummer by 

 the sudden withering of the leaves and fruit, and the discolor- 

 ation of the bark of one or more of the limbs, followed by the 

 immediate death of the part affected. This kind of blight, as 

 it has been called, being oftenest confined to a single branch, 

 or to the extremity of a branch, seems to be a local affection 

 only. It ends with the death of the branch, down to a certain 

 point, but does not extend below the seat of attack, and does 

 not affect the health of other parts of the tree. In June, 1816, 



* See Miss Morris on the Yellows, in Downing's Horticulturist. Vol. IV. p. 

 g02. 



