THE ELM BORER. 89 



bark and found, as he wrote me, &quot;great numbers of the larvae 

 of this beetle in the bark and between the bark and the wood, 

 while the latter is tattooed with sinuous grooves in every 

 direction and the tree is completely girdled by them if? some 

 placejs. There are three different sizes of the larvas, evidently 

 one, two and three years old, or more properly six, eighteen and 

 thirty months old.&quot; The tree had to be cut down. 



Dr. Harris, in his &quot;Treatise on Injurious Insects,&quot; gives an 

 account of the ravages of this insect, which we quote : &quot; On 

 the 19th of June, 1S4G, Theophilus Parsons, Esq., sent me some 

 fragments of bark and insects which were taken by Mr. J. Kich- 

 ardson from the decaying elms on Boston Common,, and among 

 the insects I recognized a pair of these beetles in a living state. 

 The trees were found to have suffered terribly from the ravages 

 of these insects. Several of them had already been cut down, 

 as past recovery ; others were in a dying state, and nearly all 

 of them were more or less affected with disease or premature 

 decay. Their bark was perforated, to the height of thirty feet 

 from the ground, with numerous holes, through which insects 

 had escaped; and large pieces had become so loose, by the 

 undermining of the grubs, as to yield to slight efforts, and come 

 off in flakes. The inner bark was filled with burrows of ths 

 grubs, great numbers of which, in various stages of growth, 

 together with some in the pupa state, were found therein ; and 

 even the surface of the wood, in many cases, was furrowed with 

 their irregular tracks. Very rarely did they seem to have pene 

 trated far into the wood itself; but their operations were mostly 

 confined to the inner layers of the bark, which thereby became 

 loosened from the wood beneath. The grubs rarely exceed 

 three-quarters of an inch in length. They have no feet, and 

 they resemble the Iarva3 of other species of Saperda, except 

 in being rather more flattened. They appear to complete their 

 transformations in the third year of their existence. 



&quot;The beetles probably leave their holes in the bark during 

 the month of June and in the beginning of July ; for, in the 

 course of thirty years, I have repeatedly taken them at various 

 dates, from the fifth of June to the tenth of July. It is evident, 

 from the nature arid extent of their depredations, that these 

 insects have alarmingly hastened the decay of the elm trees on 

 Boston Mall and Common, and that they now threaten their 

 entire destruction. Other causes, however, have probably con- 



