113 
Nothing emerged until the following spring, except a single para¬ 
de taken September 14. On the 9th April, living larvm of Sapercla 
r ere found still within the wood, but no imagos had appeared in 
lie boxes, neither were any pupae discovered. On the 17th of that 
a0 nth, both larvae and pupae were detected, and on the 2d of May, 
he first imagos appeared, three in number. On the third another 
oiago emerged, on the 5th five more, on the 7th eighteen, on the 
;th eleven, and on the 12th twenty-three, this being the largest 
lumber taken from the boxes at once. Beetles continued, however, 
o emerge at frequent intervals until the 22d June, at which time 
he last appeared, one hundred and eighteen in all, having been 
,aken alive. On the 15th September, the boxes were opened finally, 
horoughly searched, and fifty-three more dead Saperdas were found. 
Fhe boxes in which these specimens transformed, had been kept 
mcler cover, but at the natural temperature of the air. 
Although the elm borer has evidently been for several years both 
aumerous and increasing in the neighborhood where this tree was de¬ 
stroyed, the amount of parasitism developed by the experiments 
was quite insignificant, only eight parasitic insects, belonging to 
three species, appearing in the boxes as against the one hundred 
and seventy-one examples of the adult borer; and, indeed, as the 
same pieces of wood contained a great host of the larvse of Magdalis 
amicollis, from which multitudes of imagos of this species emerged 
during this spring, it is impossible to say that some or most of this 
small number of parasites may not have escaped from the latter 
species. 
Since the time of Harris, the elm tree borer has been well known 
as a destructive enemy of this most magnificent and beautiful of 
the shade trees of our towns and cities. It seems first to have at¬ 
tracted attention as an enemy of the elm in Boston, in 1847, at 
which time the trees on the Boston common were found by Harris 
to have suffered terribly from the ravages of this insect. “Several 
of them,” he says, “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. 1 heir bark was per¬ 
forated, to the height of thirty feet from the ground, with numerous 
holes, through which insects had escaped; and large pieces had 
I 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 the burrows of the grubs, great numbers of which, in various 
stages of growth, together with some in the pupa state, w T ere found 
therein; and even the surface of the wood, in many cases, was fur¬ 
rowed with their irregular tracks. Very rarely did they seem to 
have penetrated very far into the wood itself; but their opeiations 
were mostly confined to the inner layers of the bark, which thereby 
became loosened from the wood beneath.” 
The borers, (the larvae of the beetles) are similar in form and 
general appearance to the notorious round-headed borer of the 
apple, belonging, indeed, to the same genus. They rarely exceed 
three-fourths of an inch in length, are destitute of feet, and have 
the usual enlargement of the first segment of the body immediately 
behind the head. The body is white, subcylindrical, _ a little flat¬ 
tened, with the lateral fold of the body rather prominent, end or 
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