268 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
next species may be controlled by methods outlined on page 26. When 
only part of the tree is attacked, the affected branches should be cut 
off below all evidences of dead bark and be destroyed by burning. 
Should the injury be confined to a portion of the main trunk, cut away 
the bark back to healthy tissues and cover with a protective paint. 
The adult of the linden borer (Saperda vestita Say) is from 12 to 
21 mm. in length, dark reddish brown, clothed with dense olive-yellow 
pubescence, with three small black spots on each wing cover. It occurs 
in the Eastern States, its habits are similar to those of the elm borer, 
and both may be controlled by the methods given on page 26. 
The larva feeds in weakened or dying linden tr ees, boring beneath 
the bark, often deep into the wood, exuding fibrous nae Park and 
shade trees are severely injured or killed by this borer. Old, mature 
trees in a somewhat unthrifty condition seem to be more susceptible 
to injury, but when the insects are abundant young trees are often 
attacked. The trees die slowly, large branches going first. 
Smodicum cucujiforme (Say), the flat oak borer, is a small, elon- 
gate, very depressed, shining beetle from 7 to 10 mm. in length, of a 
pale dull yellow color. The eyes are strongly emarginate, the thorax 
is longer than wide, and the femora much dilated. The species occurs 
throughout the Eastern States. The larva is short, cylindrical, of 
shining texture, having the head wider than long, and retracted into 
the pr othorax. The: apex of the mandible is rounded. The prothorax 
above is finely striate, and beneath it bears a triangular plate and very 
small legs. The ampullae are dull alutaceous. The larvae excavate 
extensive meanderi ing galleries in dry heartwood of oak and hickory, 
packing them tightly with fine granular frass. 
The adults appear in July andl August, laying the eggs in crevices 
of exposed wood. The pupal cell is merely an enlar cement of the 
mine brought near the surface of the wood, through which the adult 
gnaws a way to escape. The life cycle is normally completed in 1 
year, but often in dry places the larvae feed for several years. The 
heartwood of oak and hickory shade trees is often riddled by this insect 
when access is given through a scar or wound. Stored lumber is 
frequently found infested, Fie larvae continuing to feed in it until 
the wood is thoroughly riddled. Control measures adapted to this 
borer will be found on page 38. 
The adults of the milkweed borers, 7'etraopes spp., are the stout, 
cylindrical, brick-red beetles spotted with black, found on the flowers 
of milkweeds. The larvae are also stout and cylindrical, and densely 
hairy, legless grubs having the head longer than wide and very much 
wrinkled beneath and the posterior area of the pronotum velvety 
pubescent. The ampullae bear large irregular tubercles. The larvae 
feed on the roots of milkweed and injure ornamental groupings in 
gardens. 
Tetropium cinnamopterum Kby., the eastern larch borer, is an 
oblong, cylindrical beetle of a brown to blackish color. The eyes are 
completely divided into an upper and lower part, except for a fine line- 
hike bridge. The larvae are elongate, cylindrical, having the head 
wider than long, retracted into the prothorax, and beset w ith numerous 
long hairs on the sides. The apex of the mandible is oblique and 
rather blunt. The pronotum and ampullae are velvety pubescent, the 
