INSECT ENEMIES OF EASTERN FORESTS 269 
last abdominal segment above bearing two short spines. They feed 
gregariously beneath the bark of living and dying coniferous trees, 
especially larch, packing mixed granular and fibrous frass behind them 
in the mines. It is not of much economic importance but is frequently 
associated with other species. 
Tragosoma harrisi Lec., the hairy pine borer, is a rather large beetle 
from 20 to 40 mm. in length and of a uniform brown. The thorax 
has one tooth on each side and is very hairy, as is also the under side 
of the body. Several raised lines occur on the wing covers. The larva 
is a large tough-skinned grub having four sharp-edged tubercles on the 
front of the head and three pairs of ocelli. It occurs in the North- 
eastern States and westward through the western mountains, attackin 
all conifers. The habits and economic features resemble those of 
Orthosoma (p. 258). It may be controlled by the measures indicated 
on page 43. 
Tylonotus bimaculatus Hald., the ash and privet borer, is an elon- 
gate, subdepressed beetle from 12 to 16 mm. in length, dark brown, 
with two light spots on each elytron. The thorax is nearly cylin- 
drical, having the median line and two small spots smooth and shining. 
Some antennal joints, especially the third and fourth, have two grooves 
on the outer face. The larva is of shining texture, elongate, with the 
head wider than long and the apex of the mandible rounded. One 
ocellus occurs on each side of the head. The posterior area of the 
pronotum is finely striate, and the ampullae are finely alutaceous and 
shining. The legs are very small. 
The adults fly early in summer in the Eastern and Central States, 
laying the eggs beneath scales of bark on living or dying ash trees or 
at the base of privet plants. In ash the young larvae feed principally 
in the bast tissue of the bark but when more fully matured go deeper, 
scarring the wood. In privet they mine more extensively beneath the 
bark and in the wood. They make broad meandering mines packed 
with granular frass which is not pushed out. Sap oozing from the 
wound marks the point of attack. In ash trees first the large branches 
are usually attacked and killed and later the main trunk, but in privet 
these borers always mine the base. The pupal cell is constructed in 
or beneath the bark. The larval stage extends over a period of 2 
years. In certain localities this insect becomes abundant and causes 
the malformation or death of many ash trees. Old, mature trees and 
drought-injured trees are attacked and gradually die branch by 
branch, especially those in parks or windbreaks. Privet hedges fre- 
quently suffer severely when these insects become abundant. A single 
larva is sufficient to kill an entire stem, and larvae are very difficult to 
find before the plant dies. For control measures see page 24. 
The gall-making maple boxer (Vylotrechus aceris Fisher) and the 
beech and birch girdler (VY. guadrimaculatus (Hald.)) resemble one 
another closely in both the adult and larval stages. The adult of 
X.aceris is somewhat smaller than that of Y. quadrimaculatus, and has 
spots on the thorax much less distinct and the markings of the elytra 
stronger. :, 
X ylotrechus aceris occurs in the Eastern States. The larva is cream 
colored, rather robust, having the head wider than long, one ocellus 
on each side, and the mandible rounded at the apex. The posterior 
