Hardy Pests Back

You don’t want to know the hemlock wooly adelgid. The invader — no bigger than a period — is terrorizing towering trees, both hemlock and spruce.
    These pests threaten to wipe out eastern hemlock forests, a loss that could be as dreadful as the loss of American chestnuts. The bug is loose in half the evergreen’s geographic range, 11 eastern states from Georgia to Massachusetts.
    The fight is on, with two Maryland agencies injecting insecticide into thousands of hemlock trees and soil on public lands across the state. The wooly adelgid, which leaves telltale white, woolly wax spots on young hemlock twigs, is at its worst in our western counties.
    The pencil-tip adelgid joins the ranks of Maryland public tree enemies. The emerald ash borer, here a decade, gets special attention May 18-24, days designated by Gov. Martin O’Malley as Emerald Ash Borer Awareness Week.
    The iridescent beetle that can fit on a penny has been eating its way through Maryland’s ash trees — and ash in many states east of the Mississippi. To stop its decade-long advance, Maryland foresters have set up a movable quarantine barrier with sentry traps hung in trees throughout susceptible areas.
    The ash tree is a popular city tree as well as an important woodland tree in the Chesapeake watershed and a mainstay of the timber industry. Ash contributes wood for furniture, flooring, bowling alleys, church pews, guitars and baseball bats.
    Losses from the ash borer could exceed $227.5 million in the Baltimore metro area alone.
    What can you do to help?
    In all counties west of the Chesapeake Bay and Susquehanna River it’s against the law to transport firewood because ash borers could have infiltrated the wood. So far, the Eastern Shore is uninvaded. If you have ash trees, look alert. Ash borer infestation shows up in eaten leaves, diminished tree canopy and shoots or sprouts emerging below dead portions of trunk. Woodpeckers are drawn to the trees to feed on the borers. Beneath the bark, D-shaped exit holes tell you the borer was there.