Packard.] 
INSECTS OF THE FOEEST. 
249 
two they live unobserved among the topmost shoots, and 
are not usually detected until half grown. Towards the end 
of June they descend^ to the ground and transform to chrys¬ 
alides, and in about a week after the moth appears. 
The most formidable borer of the elm tree is the three¬ 
toothed Compsidea (Fig. 189, beetle and larva). It con¬ 
sumes the inner bark and sometimes girdles the tree so as 
to suddenly kill it. The female lays her eggs in June on 
the trunk of the tree. The worms attain maturity in the 
Fig. 189. 
Elm Tree Borer. 
Fig. 190. 
Short lined Elm Borer. 
autumn of the third year succeeding, when they may be 
found under the bark. Another elm tree borer, but not as 
yet known to be at all common, is the short lined Physocne- 
mum (Fig. 190). 
Closely allied to the elm tree borer is the linden tree 
borer (Fig. 191, Saperda vestita, with its larva; a, b, c, dif¬ 
ferent views of the head ; d, body segments, enlarged). It 
perforates the linden tree, while the poplar is infested by 
25 
