INSECT ENEMIES OF EASTERN FORESTS 259 
entrance heals over and shows no sign of their presence. It is a most 
important factor contributing to wind breakage of shade trees. For 
control, see pages 24 and 38. 
Phymatodes testaceus (1), the tanbark borer, is an elongate de- 
pressed beetle from 8 to 18 mm. in length. The thorax of this borer is 
rounded and yellowish, and the elytra may be either yellowish or blue. 
The larva is somewhat depressed, having a thick, shining skin, the 
head wider than long, one black ocellus beneath the chitin, and the 
apex of the mandible rounded. The pronotum is irregularly striate 
to granulate behind, and the ampullae are covered with small flattened 
eranulations. Legs are present. The larva feeds beneath or in the 
bark of dead oaks and sometimes in stored hemlock bark in the Eastern 
and Central States. 
The adults fly in the spring, laying eggs beneath scales of the bark. 
The larval mines, extending within or beneath the bark, are loosely 
filled with frass. In tanbark removed from the trees the larvae mine 
entirely in the bark. Pupation takes place in the bark or sapwood. 
The life cycle may require 1 year, 2 years, or longer. ‘This insect is of 
economic importance only when it attacks bark of oak and hemlock 
stored and piled for tanning purposes. Under such conditions it will 
often destroy a great quantity of the material. A.D. Hopkins reports 
the destruction of over $50,000 worth of bark at one tannery. To 
avoid such losses the bark should be used before it is 3 years old. 
Physocnemum andreae Hald., the cypress bark borer, is a rather 
large, robust beetle, from 11 to 21 mm. in length, and of a reddish- 
brown color. Near the base of the thorax occurs a small tubercle and 
on each elytron a white arcuate mark. The femora are club-shaped. 
The larva is elongate and slightly depressed, having the head wider 
than long, and the apex of the mandible rounded. The pronotum is 
irregularly striate, and the ampullae are alutaceous and shining, with 
the last two ventral ones corneous at the sides. Legs are present. The 
larva feeds between the bark and wood of recently dead or dying 
cypress. 
The adults fly early in the summer, laying the eggs beneath scales of 
bark. The larvae feed beneath the bark and excavate very large mines 
packed with granular frass, and deeply scar the sapwood. ‘The pupal 
cells are constructed the following spring in the sapwood, the adults 
chewing their way out through the bark. In lumbering operations in 
the cypress swamps of the South this insect causes much damage to 
the wood of felled and girdled cypress. Often the sapwood is com- 
pletely destroyed. It is also injurious to rustic work constructed 
from these trees. Control measures for use against this insect are 
given on page 38. 
Physocnemum brevilineum (Say), the elm bark borer, is an elon- 
gate, depressed, bluish-black beetle, from 12 to 16 mm. in length. The 
thorax is subglobose with a rounded tubercle on each side near the 
middle, and each elytron bears three short raised whitish lines. The 
femora are clubbed. The larvae resemble those of P. andreae but lack 
the chitinous plates on the last ventral segments. They feed in the 
corky bark of living elm trees in the eastern part of the United States. 
The adults appear late in the summer and deposit the eggs beneath 
scales of the bark on living elm trees. The larvae excavate meander- 
