INSECT ENEMIES OF EASTERN FORESTS 245 
This species occurs throughout the Eastern States wherever elders 
grow. The adults fly about the time the host flowers are in bloom. 
They lay the eggs in crevices of the bark at the base of the stem and 
the larvae, upon hatching, bore down into the roots, where they feed 
for 2 or 3 years. The mines are packed with fibrous frass and finally 
extend through the center of the stem to the level of the ground or 
above, where the simple pupal cell is made. Some species cause a 
large gall at the base of the stem. When these insects become numer- 
ous, they not only cause serious injury to the plants but often kill them 
outright. Elders used for ornamental purposes are occasionally 
rendered very unsightly by the destruction of many canes. 
Beetles of the genus /buria are readily recognized by the two pairs 
of ivory-white spots on each wing cover. <A typical form is Hburia 
guadrigeminata (Say), the ivory-marked beetle, which ranges from 
14to24mm.inlength. It is elongate, subcylindrical, and pale yellow. 
Each wing cover has two small longitudinal ivory spots close together 
at the base and a second similar pair just behind the middle. The 
thorax has two blackish tubercles dorsally and a short, sharp spine 
oneach side. The larvae are rather robust and wedge-shaped, tapering 
eradually posteriorly, with tough, shining integument sparsely covered 
with golden hairs. The head is wider than long, with the apex of the 
mandible rounded. The legs are distinct, long, and four-jointed. 
The larva is a true heartwood borer and prefers dry, solid wood, in 
which it excavates large contorted mines very tightly packed with 
frass. Mature oaks having “catfaces,” or scars, through which the 
larvae can gain access to the heartwood are often badly damaged. 
Lumber in the process of seasoning is also subject to occasional at- 
tack by the adult beetles. Oak, hickory, ash, chestnut, maple, and 
cypress are liable to infestation. Beetles sometimes emerge from 
flooring and furniture several years after these are placed in a build- 
ing, but it is not definitely known to attack such material after it 1s 
in use. Fumigation or removal of infested woodwork (p. 44) are 
recommended for control of house infestations. 
The twig pruner (Hypermallus villosus (F.)) is an elongate, sub- 
cylindrical, brownish beetle from 10 to 17 mm. in length, having spines 
on the first few antennal joints and at the tip of the elytra. The 
thorax is nearly cylindrical. The larva can be recognized by the 
elongate, slender form and shining texture, having the head wider than 
long, two ocelli on each side, and the apex of the mandible rounded. 
The pronotum is shining and somewhat striate, the two segments Just 
behind bear an X-shaped impression above, and the ampullae are 
shining. Legs are present. The larvae feed in the branches of many 
hardwoods, and cut these branches from the trees. 
This species occurs throughout the eastern part of the United States. 
The adults fly about the time the oak leaves begin to form, and deposit 
the eggs near the tip of the twigs in the axil of a leaf. The young 
larva mines down the stem, increasing in size as it goes, until late in 
the summer it severs the branch by several concentric cuts from the 
center outward, except for the thin bark. ‘These branches, from 14 
inch to 2 inches in diameter, break with the wind and fall to the 
ground. The larva retreats up the fallen stem and secures itself 
between two wads of fibrous frass, where it pupates early the follow- 
ing spring, or in the fall. Shade and park trees are frequently so 
