INSECT ENEMIES OF EASTERN FORESTS 263 
Romaleum rufulum (Hald.), the red oak borer, is an elongate, sub- 
cylindrical beetle from 22 to 28 mm. in length, brownish, with spots 
of lighter pubescence. The thorax is cylindrical, with two small 
tubercles on the disk and a triangular smooth spot behind. The larva 
is elongate, robust, and of a shining texture. The head is wider than 
long and has one large ocellus cn each side. The apex of the mandible 
is rounded. The pronotum is shining and irregularly striate, and the 
ampullae are alutaceous and shining. Legs are present. 
The adults appear when the chestnut and chinquapin are in bloom 
and lay the eggs beneath scaies of bark on living oak trees. The young 
larva feeds the remainder of that season and the early part of the 
following beneath the bark in the cambium, killing a large spot of 
bark and exuding granular frass from a hole which is enlarged as the 
larva grows. Moisture also flows from this wound conspicuously 
marking the point of injury. During the second season a large exca- 
vation is carried directly upward and into the heartwood, at the top 
of which the larva pupates behind the plug of fibrous frass (fig. 54, 4), 
after cutting a hole through the bark for the adult to emerge. 
The insect is found throughout the Eastern and Central States, 
where locally a large percentage of the oaks are attacked, causing 
defects and serious degrade in the timber. Ants and fungi entering 
these wounds extend the injury. Occasionally the beetles become 
numerous enough to kill branches or the entire tree. Such is the case 
in some southern parks and cities, where hundreds of fine old shade 
trees have been lost. All sizes of trees are attacked, but large mature 
trees seem to be preferred. For useful control methods see page 24. 
Both the adult and larva of Romalewm cortiphagus Craighead and 
Kknull, the oak-bark scarrer, very closely resemble the preceding insect, 
but the larva can be distinguished by small transverse wrinkles across 
the under side of the head, whereas in #. rwfulum this region is longi- 
tudinally wrinkled. It feeds only in the thick bark of mature oak, 
causing a characteristic scar on the surface of the bark. It occurs 
in the Eastern States and west through the Ozark Mountains. 
The adult appears while the chestnut or chinquapin is in full bloom, 
or a little later, and deposits the eggs in crevices of the bark. The lar- 
vae feed at first in the thick ridges of the bark, going deeper as they 
increase in size. The mines are tightly packed with granular frass. 
After 3 or more years they burrow deep into the inner bark, where 
a large excavation is made for the pupal cell. This cell usually injures 
the cambium, resulting in a large black defect, which defaces many 
annual layers of growth and causes the formation of the characteristic 
scar on the outer surface of the bark. This defect is commonly found 
in the wood of large thick-barked oak trees throughout the Appala- 
chian Mountains and westward, and causes considerable degrade of 
the lumber. No practical control measures can be recommended in the 
forests. The utilization of the bark of certain species of oaks for 
tannin extract destroys many of the larvae. 
The borers of the genus Saperda F. are large to medium-sized, 
cylindrical, variously colored beetles. The front of the head is quad- 
rate and very flat, the antennae are about as long as the body, and the 
thorax is cylindrical and without spines or tubercles. The first joint of 
the hind tarsi is quite elongated. The larva is elongate, cylindrical in 
form, having the head longer than wide, and the mandible obliquely 
