THE BOSTRICHIANS. 91 



externally, and end with a short hook; and the joints of 

 the feet are slender and entire. This insect cannot be 

 retained in the genus Scolytus, as defined by modern nat- 

 uralists, but is to be placed in the genus Tomicus. The 

 minuteness of the insect, the difficulty attending the discov- 

 ery of the precise seat of its operations before it has left the 

 tree, and the small size of the aperture through which it 

 makes its escape from the limb, are probably the reasons why 

 it has eluded the researches of those persons who disbelieve 

 in its existence as the cause of the blasting of the limbs of 

 the pear-tree. It is to be sought for at or near the lowest 

 part of the diseased limbs, and in the immediate vicinity of 

 the buds situated about that part. The remedy, suggested 

 by Mr. Lowell and Professor Peck, to prevent other limbs 

 and trees from being subsequently attacked in the same way, 

 consists in cutting off the blasted limb below the seat of injury, 

 and burning it before the perfect insect has made its escape. 

 It will therefore be necessary carefully to examine our pear- 

 trees daily, during the month of June, and watch for the first 

 indication of disease, or the remedy may be applied too late 

 to prevent the dispersion of the insects among other trees. 



There are some other beetles, much h'ke the preceding in 

 form, whose grubs bore into the solid wood of trees. They 

 were formerly included among the cylindrical bark-beetles, 

 but have been separated from them recently, and now form 

 the family BOSTRICHID^E, or Bostrichians. Some of these 

 beetles are of large size, measuring more than an inch in 

 length, and, in the tropical regions where they are found, 

 must prove very injurious to the trees they inhabit. The 

 body in these beetles is hard and cylindrical, and generally 

 of a black color. The thorax is bulging before, and the 

 head is sunk and almost concealed under the projecting fore 

 part of it. The antennas are of moderate length, and end 

 with three large joints, which are saw-toothed internally. 

 The larvae are mostly wood-eaters, and are whitish fleshy 

 grubs, wrinkled on the back, furnished with six legs, and 



