be most severe in sparsely stocked stands or in stands growing 
on poor sites. (568). 
Agrilus arcuatus var. torquatus LeC., the hickory spiral borer, has 
been recorded from New York, Ohio, North Carollina, and Mis- 
sissippi. It appears to favor hickory and pecan, but also infests 
many other hardwoods. It, or a closely related species, has been 
observed attacking young oaks and other hardwoods in the 
Piedmont section of the South (40). Adults are about 8 mm. long. 
Males have a greenish-bronze head and thorax, purplish-black 
elytra, and the brassy underparts. Females are completely bronze. 
Adults appear from May to July and feed on the leaves of 
their host, eating large irregular holes. Eggs are deposited singly 
on the bark surface or on terminals or twigs, usually near the 
base of a small shoot of the current season’s growth. The larvae 
feed downward beneath the bark during the summer, and, during 
the fall, they sever the wood by constructing a spiral burrow. 
The following spring, they continue to feed beneath the bark, 
constructing long, irregular tunnels that deeply engrave the 
wood. When they are full-grown, they make a second transverse 
spiral cut around the wood, working first toward the pith and 
then out again to the phloem, leaving the bark intact. Then, they 
mine upward in the phloem for an inch or two and construct 
pupal cells entirely within the pith. Two years are required to 
complete the life cycle (104). This species is often very destruc- 
tive of hickory seedlings in the South. 
Agrilus acutipennis Mann. has been observed attacking overcup 
oaks in Louisiana and Arkansas (539). Eggs are deposited on the 
bark. The larvae bore through the bark and then excavate patches 
of inner bark up to one-half inch in diameter. Later, they enter the 
wood and tunnel spirally upward in the outermost growth ring. 
Pupation occurs within the tunnel and the life cycle requires 2 
years. 
Damage by Agrilus acutipennis results in a defect known as 
“grease spot.” This is caused by a fungus that spreads through 
the wood from the tunnels. In cross-section, grease spots are oval 
to diamond- or spindle-shaped and about 18 mm. wide. Their 
presence in lumber greatly reduces its value. Infestations have 
been found frequently in river bottoms where the trees were 
subject to backwater flooding during the winter and spring. In 
such situations, entire stands of trees over one-half inch in di- 
amter are usually infested. 
Many other species of Agrilus also occur in eastern forests 
Some of these and their more important hosts are as follows: A. 
juglandis Knull—butternut; A. difficilis Gory—honey locust; A. 
leconteit Saund. and A. celtt Knull—hackberry; A. betulae Fisher 
—river birch; A. cephalicus LeC.—dogwood; A. fuscipennis Gory 
—persimmon; A. egenus Gory—black locust; and A. otiosus Say 
—hickory, oak, maple, dogwood, red bud, walnut, and persimmon. 
The genus Buprestis L. is represented by a fairly large number 
of wood boring species. Many seem to prefer dead and decayed 
wood; others are found in either weakened or perfectly healthy 
trees. The larvae construct tunnels in the sapwood and often 
the heartwood and frequently cause serious damage. The adults 
come in many different colors: metallic green, blue, gold, red, 
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