100 INSECTS INJURIOUS TO VEGETATION. 



that these trees have greatly suffered, in past times, from the 

 ravages of canker-worms. Moreover, the impenetrable state 

 of the surface-soil, the exhausted condition of the subsoil, and 

 the deprivation of all benefit from the decomposition of accu- 

 mulated leaves, which, in a state of nature, the trees would 

 have enjoyed, but which a regard for neatness has industri- 

 ously removed, have doubtless had no small influence in 

 diminishing the vigor of the trees, and thus made them faU 

 unresistingly a prey to insect devourers. The plan of this 

 work precludes a more full consideration of these and other 

 topics connected with the growth and decay of these trees; 

 and I can only add that it may be prudent to cut down and 

 burn all that are much infested by the borers. 



The tall blackberry, Ruhus villosus, is sometimes cultivated 

 among us for the sake of its fruit, which richly repays the care 

 thus bestowed upon it. It does not seem to be known that 

 this plant and its near relation, the raspberry, suffer from borers 

 that live in the pith of the stems. These borers differ some- 

 what from the preceding, being cylindrical in the middle, and 

 thickened a little at each end. The head is proportionally 

 larger than in the other borers; the first three rings of the body 

 are short, the second being the widest, and each of them is 

 provided beneath with a pair of minute sharp-pointed warts or 

 imperfect legs ; the remaining rings are smooth, and without 

 tubercles or rasps ; the last three are rather thicker than those 

 which immediately precede them, and the twelfth ring is very 

 obtusely rounded at the end. The beetles from these borers 

 are very slender, and of a cylindrical form, and their antennas 

 are of moderate length and do not taper much towards the end. 

 The species which attacks the blackberry appears to be the 

 Saperda ( Oberea) tripunctata of Fabricius. It is of a deep 

 black color, except the fore part of tiie breast and the top of 

 the thorax, which are rusty yellow, and there are two black 

 elevated dots on the middle of the thorax, and a third dot on 

 the hinder edge close to the scutel ; the wing-covers are coarsely 

 punctured, in rows on the top, and irregularly on the sides and 

 tips, each of which is slightly notched and ends with two little 

 points. The two black dots on the middle of the thorax are 



