wood. The winter is spent in the larval stage in the twig. Pupation occurs in the 
spring between two wads of fibrous frass. The portion of the twig containing the 
cell may have been girdled previously. Occasionally dogwoods and elms are 
seriously damaged. Cutting off and burning infested twigs might be helpful in 
control (220). 
Oberea schaumii LeConte occurs in southern Canada and south in the Eastern 
States to the Gulf Coast. It breeds in poplar. Adults are about 14 mm long; the 
thorax is yellowish or yellowish orange to black and is marked by four round, 
smooth spots (935). The elytra are either yellowish or black. Eggs are laid in the 
stems and branches of suckers and seedlings; also in the twigs of saplings, poles, 
and large trees. The larvae feed near the pith, excavating tunnels up to 15 cm long, 
and boring holes to the outside for the expulsion of frass. Black, necrotic areas 
develop around these holes. The life cycle usually takes 3 years in northern 
Michigan, but a few take 2 or 4 years. Infested twigs do not die and are usually not 
sufficiently weakened to permit windbreakage. 
Oberea myops Haldeman, the rhododendron stem borer, breeds in rhodo- 
dendron, azalea, and mountain-laurel. The adult is pale yellow and about 12 to 15 
mm long. There are two black spots on the thorax and the elytral margins are dark. 
Eggs are deposited in the bark of twigs between two girdles about | cm-apart. The 
larva bores down the twig, into the stem, and on down to the ground. Here, it cuts 
off the stem, and then bores into the roots. Frass is expelled through holes along the 
stem and at the ground line. This species is frequently a serious pest in ornamental 
plantings of rhododendron. Cutting and burning infested twigs as soon as they are 
noticed is recommended. 
Oberea ocellata Haldeman, the sumac stem borer, occasionally causes serious 
injury in sumac plantings. Adults are about 13 to 15 mm long. The head and 
underside of the body are red; the thorax is red with two black spots on the disk; and 
the elytra are black. The female girdles the tip of the plant and then lays an egg just 
below the girdle. The larva bores down the stem through the pith to the roots. Here, 
it constructs long tunnels and feeds for two seasons. During the fall of the second 
year, it cuts the plant off near the ground and plugs the stub with a wad of frass. 
Below this plug, pupation occurs the following spring. 
Oberea ruficollis (F.) breeds in the stems and roots of sassafras. Adults are pale, 
reddish yellow and about 18 to 20 mm long. The antennae, tibiae, and tarsi are 
black and the elytra are densely clothed with fine gray hairs. The feeding habits of 
the larvae are similar to those of O. ocellata except that they seldom cut off stems 
near the ground. Infested plants usually survive but may be badly deformed. 
Other species of Oberea sometimes encountered are: O. pallida Casey—in alder 
in Pennsylvania; O. ulmicola Chittenden—in the branches of oak, elm, hickory, 
dogwood, and black cherry in Ohio and Pennsylvania; and O. ferruginea Casey—in 
willow canes. 
The genus Oncideres contains several species, the females of which deposit their 
eggs in previously girdled terminals, twigs, or small branches of large trees, or in 
the stems of seedlings or sprouts. The girdled portions soon die and most of them 
fall to the ground. The larvae feed in the wood of this fallen material until the 
middle of the following summer, loosely filling their mines with frass. Pupation 
occurs in a cell formed by walling off a portion of the mine with fibrous frass. The 
adults appear in late summer or early fall and feed on the thin bark of twigs or 
stems. There is one generation per year in the South. In the North, many larvae do 
not pupate until the second year. 
300 
