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Courtesy lil. Nat. Hist. Surv. 
Figure 133.—Adult of the elm borer, 
Saperda tridentata. 
Adults are present from late spring to late summer, and feed on young leaves and 
young twigs. Eggs are deposited in small holes chewed in bark crevices, usually on 
freshly cut logs or weakened trees. The larvae bore beneath the bark, filling their 
mines with fibrous frass, and completely destroying the phloem and cambium 
(973). When they reach maturity they bore into the wood and construct cells in 
which to pupate. There 1s usually one generation per year; however, in rapidly dried 
wood 3 years may be needed to complete the life cycle. 
Park and shade tree elms, especially the older ones and those in a weakened 
condition, are severely injured by this species. Affected trees tend to die very 
slowly, a branch at a time. The removal of infested branches is sometimes helpful in 
control. 
Smodicum cucujiforme (Say), the flat powderpost beetle, occurs throughout the 
Eastern United States. The larvae excavate extensive meandering galleries in dry 
heartwood of oak and hickory. Stored lumber is frequently infested, the larvae 
continuing to feed in it until the wood is thoroughly riddled. The adult is small, 
elongate, very depressed, dull yellowish, shiny, and 7 to 11 mm long. Adults 
appear from June to August. Eggs are laid in crevices of exposed wood. The larvae 
excavate tunnels about 3 mm in diameter in the wood, tightly packing them with 
frass. Pupation occurs in an enlarged portion of the mine near the surface of the 
wood. There is normally one generation per year. In dry wood, several years may 
be required to complete the life cycle. 
The genus Oberea is represented in the Eastern States by a number of slender, 
cylindrical beetles, the larvae of which bore in the twigs, branches, or stems of 
various forest, shade, and ornamental trees. These beetles are distinguished by the 
presence of a broad tooth on each tarsal claw. 
The dogwood twig borer, O. tripunctata (Swederus), breeds in dogwood, elm, 
sourwood, laurel, azalea, viburnum, and various fruit trees in the Eastern United 
States. The adult is yellowish and about 14 mm long. The head is reddish or dark 
brown and there is a black spot on the scutellum. Adults appear in early spring and, 
after girdling the tip, the female deposits her eggs in living twigs of the host. The 
larva bores down the center of the twig, making a long series of holes for the 
expulsion of frass and cutting off portions of the twig as it bores into the green 
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