Minor borers

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< Oak

Solomon, J.D.; McCracken, F.I.; Anderson, R.L.; Lewis, Jr. R.; Oliveria, F.L.; Filer, T.H.; Barry, P.J. 1987. Oak Pests: A Guide to Major Insects, Diseases, Air Pollution, and Chemical Injury. Protection Report R8-PR7. USDA Forest Service, Southern Forest Experiment Station. 69 p.

Insect Injury Control
Little carpenterworm (Prionoxystus macmurtrei);

larva pink to white, dark head and thoracic shield, 2.25 inches (57mm);
adult gray-mottled moth; life cycle 2 to 3 years.

Trunks and branches of sawtimber and shade trees; prefers red oaks; mine under bark,
and gallery in wood .4 x 6 inches (I x 15 cm); frass of wood chips and excrement pellets;
causes lumber degrade, disfigures ornamental trees.
Beech borer (Goes pulverulentus);

roundheaded larva, white, legless, cylindrical, about 1.5 inches (37 mm); adult
brownish-gray longhorned beetle; life cycle 3 to 5 years.

Trunks of saplings and poles of red oaks; attacks are clustered; galleries
are about .4 x 8 inches (0.9 x 20 cm); grayish frass with fibrous shreds extruded in ribbons; degrade,
entries for decay, stem breakage.
Spotworm borer (Agrilus acutipennis);

larva is slender, flattened, white, about 1.3 inches (32 mm) long; adult beetle is
narrow, dark metallic blue, about .5 inches (12 mm) long; a generation requires 2 years.

Trunks over .5 inch (12 mm) in diameter in white oak group, particularly heavy on
overcup oak in river bottoms; larvae tunnel spirally in outermost growth ring; spot stains and
frass-packed tunnels are defects that degrade lumber.
Flatheaded appletree borer (Chrysobothris femorata);

larva (figure 32) is flatheaded, white, about I inch (25 mm) long; adult beetle is
oval, flattened, greenish bronze, about .6 inch (16 mm) long; one generation per year.

Trunks and branches of red and white oaks of all sizes; larvae bore into phloem
and outer sapwood; galleries girdle and kill small trees; newly transplanted trees and those weakened
or stressed are most susceptible.
Oak branch borer (Goes debilis);

roundheaded larva, legless, yellowish-white, about .6 inch (15 mm); adult longhorned
beetle, mottled reddish-brown and gray; life cycle 3 to 4 years.

Small branches and terminals about .3 to 1.5 inches (9 to 37 mm) in diameter, mainly
white oaks; attacks near crooks and branch crotches; galleries about .2 x 3 inches
(6x75 mm); yellowish frass protrudes from elongate entrance hole; infested stems become swollen,
and often break or die back.
Oak-stem borer (Aneflormorpha subpubescens);

roundheaded larva, slender, about .7 inch (18 mm) long; adult narrow, light brown,
spine on the third and fourth segments of antennae. One generation per year.

Seedlings and sprouts about .5 to 1 inch (12 to 25 mm) diameter; red and white oaks;
larva bores down center of stem, cutting off sections, burrows to stem base or roots to overwinter;
frass is ejected through row of small holes in bark, kills large numbers of seedlings and sprouts in Southeast.

Controls for insects and diseases

1. Natural controls often adequate.
2. Place sticky bands around trunk.
3. Prune infected twigs and destroy.
4. Rake fallen infected leaves and destroy.
5. Maintain high tree vigor with cultural practices.
6. Open-grown trees most susceptible; maintain good stocking.
7. Identify and remove brood trees.
8. Prevent or minimize injuries.
9. Mechanically "worm-out" with knife and wire.
10. Wrap trunk of newly transplanted trees.
11. Control with chemical insecticide.
12. Control with biological insecticide.
13. Control with gallery fumigation.
14. Remove and burn diseased materials from the tree and area.
15. Control with chemical fungicide.
16. Control with iron chelate.