314 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
tionable whether the insects do more than hasten the death of trees 
which, in any event, would succumb to the drastic changes in their 
surroundings. It therefore is probably unnecessary to consider con- 
trol of the four-eyed bark beetie, but in lumbering operations where it 
is numerous the larger slash and cull logs should be treated if the cut- 
ting is discontinued suddenly. 
The genus Carphoborus Eichh. contains small, dark-brown to black 
beetles which have numerous small cinereous scales and the elytral 
declivity with the first interspace slightly and the third strongly ele- 
vated. Only two species have been reported in the East, and both are 
quite small, being less than 2 mm. long. They breed in broken, cut, 
and dying twigs of the various southern pines, and are not responsible 
for any damage. The burrows are of the true radiate type, having 
from three to ‘eight ego galleries in each engraving. There are two 
or more eenerations a year. The two species, C. bicristatus Chapuis 
and C. bifurcus Hichh., are fairly common throughout the Southern 
States and occasional specimens may be taken as far north as New 
York. Additional information on this beetle may be found in publi- 
cations by Blackman (38) and Chamberlin.”4 
The genus Chramesus Lec. is represented in the East by two species 
of small, stout, strongly convex, “humpbacked beetles,” less than 2 
mm. long. They are readily distinguished by the form and also by 
the antenna, the club of which is large, long-oval, and unsegmented, 
and is attached to the funicle at one side. Neither of these species 
is injurious, as they breed in broken or dying twigs and small limbs. 
They are both monogamic forms, the adults making longitudinal, un- 
branched egg galleries, partly in the bark and partly i in the sapwood, 
with the eggs evenly spaced in niches at each side. C. hicoriae Lec. 
breeds in cut or badly injured twigs and small branches of various 
species of hickory. It occurs generally throughout the eastern half of 
the United States. C. chapuisii Lec. breeds in cut or injured small 
limbs and twigs of hackberry. It is found from Pennsylvania to Mis- 
sissippi and Lom siam. More detailed information is.to be found in 
Blackman (35, 44). 
The species an Phthorophloeus Rey. may be readily distinguished 
from other bark beetles by the loosely jointed antennal club, each of 
the three parts of which are extended on the inner side into a leaflike 
process. Several species of this genus occur in the eastern half of the 
United States, and all but one of these breed in broad-leaved trees. 
The burrows are of the transverse forked type, but appear to be made 
by a single pair of beetles. The species are either unaggressive, attack- 
ing only dead or cut material, or only moderately aggressive, attacking 
material which is still capable of some resistance. 
One habit well known for several of the species is perhaps the cause 
of more injury than that produced by their ordinary breeding habits. 
The young adults emerge from their larval hosts in the fall, burrow 
into the bark of living ‘trees s, and spend the winter and early spring 
at the contact of the outer bark and the phloem. Their burrows often 
extend into the outer part of the living bark and cause an irritation 
resulting in an abnormal growth, w hich may show as a swelling on the 
trunk of a tree b: adly affected. While this habit of the beetles causes 
*4 See footnote 22, p. 302. 
