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Importance.
-- This borer is found in the East wherever its host species grow. Young
trees 2 to 8 inches (5 to 20 cm) in diameter, in the white oak group
are attacked. Some degrade occurs.
Identifying the
Insect (figure 22a). -- The larva is moderately robust and cylindrical;
1 to 1.5 inches (25 to 37 mm) long; yellowish white; head strongly depressed
with dark brown mandibles; and legless. The adult beetle has a spine
on each side of the thorax; about .8 to 1 inch (20 to 28 mm) long; white
and brown mottled; and antennae about as long as the body.
Identifying the
Injury (figure 22b). -- Egg niches .25 inch (6 mm) in diameter cut
singly in the bark are followed by oozing sap and teh extrusion of fine,
moist frass. Later, the insects eject yellowish, ribbon-like pieces
of frass containing pulverized or fibrous, shredded wood. Galleries
are about .5 inch (12 mm) in diameter and 6 inches (15 cm) long. Each
borer leaves a small, elongate entrance hole and a circular .3 inch
(8 mm) exit hole.
Biology.
-- Adult beetles emerge during May to June and deposit eggs. Eggs hatch
in about 3 weeks and the larvae tunnel directly into the wood. Pupation
occurs within the gallery and lasts 2 to 3 weeks. A life cycle requires
3 to 5 years.
Control.
-- Woodpeckers and sap-ooze are the most important natural controls.
Remove brood trees. Follow practices that promote stand vigor. Direct
controls are occasionally needed.
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