58 Farmers’ Bulletin 1169. 
ASPEN BORER.” 
_ Character of damage.—The aspen borer is generally quite destruc- 
tive to poplar trees and particularly so to aspen and cottonwood 
throughout the United States, especially in the Middle and Western 
States. Malformation of the trees, death of limbs and often the 
entire plant, and riddling of the main trunk with large holes which 
cause the tree to 
break off in the 
wind, are the usual 
results of the at- 
tack, 
EKaternal evt- 
dence of infesta- 
tion—In June and 
July irregular scars 
occur on the main 
trunk, especially 
around the crotch 
of branches, from 
‘Fic. 36.—Aspen borer: Side and top views of beetle. En- which sap exudes 
latied Pt Eoi re and fibrous boring 
dust is thrust out. Later or older evidence of infestation is the en- 
largement of holes, extrusion of more or larger bits of frass, and 
often the death of limbs. The adults (fig. 36) are rarely seen because 
they feed on the young twigs and lay their eggs at night. 
Description and habits —The boring stage or larva (fig. 87) of the 
poplar borer is a yellowish, cylindrical grub which can be distin- 
euished from all other insects boring in poplar by the presence of 
numerous fine, short, 
hard points on a 
plate immediately 
back of the head. It 
hatches from an egg 
laid in a scar on the 
bark by a grayish 
evlindrical beetle F16. 37.—Aspen borer: Grub, much enlarged. (Hofer.) 
(fig. 836) with numerous brown spots over the body. The eggs are 
laid during the period from May to July, the young larve mining 
during the first year beneath the bark, and during the succeeding two 
years deep in the wood. 
Remedies.—F¥or shade trees and small plantations or groves spray- 
ing of infested trunks during the late summer months with poisoned 
“| Saperda calearata Say. 
