Oak Phylloxerids
From Bugwoodwiki
Contents |
Importance
Phylloxerids are very small, aphid-like insects that attack the foilage and buds of red and white oak trees of all sizes. Heavy infestations stunt and weaken the trees. The distorted foliage mars the beauty of ornamentals.
Identifying the Insect
Phylloxerids are small .01 to .02 inch (0.3 to 0.6 mm) long, aphid-like, lack cornicles and usually spiny in appearance. Winged forms have reduced wing veination. They are usually found in clusters.
Identifying the Injury
Buds and young developing leaves (undersurface) on terminals and branch ends are attacked, causing the leaves to curl and twist. Growth may be reduced or stopped. Mature and nearly mature leaves are unaffected. Damage occurs during spring and early summer.
Biology
The Biology is not well known, but overwintering occurs as eggs in bark crevices. Eggs hatch during the spring. There appear to be several generations per year.
Control
Natural controls usually keep damage to a minimum. Ornamental may require chemical control.
References
J. D. Solomon, F. I. McCracken, R. L. Anderson, R. Lewis, Jr., F.L. Oliveria, T.H. Filer, and P.J. Barry
