ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Thursday, September 5, 1996 TAG: 9609050090
SECTION: VIRGINIA PAGE: C-1 EDITION: METRO
COLUMN: What's On Your Mind?
SOURCE: RAY REED
Q: A recent trip north on Interstate 81 prompts this question: Why are some of the trees turning brown?
A: You probably saw black locust trees that are being attacked by the leaf miner insect, said a forester with the Virginia Department of Forestry.
The leaf miner sucks out the chlorophyll, leaving the foliage brown.
This does not kill the tree, and the leaf miner has been less active than usual this year, said Frank Burchinal, a regional forester in Salem.
Two other bugs that attack trees, the pine bark beetle and gypsy moth, have been pretty quiet this year as well, Burchinal said.
The gypsy moth, in fact, has run into a natural enemy that brought it to a standstill this year. For the first time since 1984, the Department of Forestry has declared there was no defoliation by the moth.
That doesn't mean the moth has been eradicated, or that it won't make a comeback.
But, after 850,000 acres of hardwood trees were gnawed in varying degrees in 1995, the moth's activity was too little to measure from the air this year, said Tim Tigner, an entomologist with the forest service in Charlottesville.
The moth over the past dozen years has done most of its damage in three counties: Rockingham, Shenandoah and Page. It has reached Roanoke and points south and west, and at least one patch of hardwood trees on the Roanoke-Botetourt county line was sprayed this year to control the moth.
While spraying may help control isolated outbreaks, the most effective gypsy moth counterattack has come from nature itself.
A fungus that kills the moth caterpillar was found to be widespread in 1995 and, thriving in a wet spring this year, it became a devastating epidemic to the moths.
The fungus, Entomophaga maimaiga, was introduced to the northeastern United States in the early 1900s to control the moth, but there was no evidence it became established.
The fungus reappeared in the Northeast in the late 1980s, and nobody is sure how it got there, Tigner said.
The thinking is, it arose on its own and has spread through the moth-infested portions of Virginia.
The state Department of Agriculture introduced the fungus in parts of Virginia in 1991, but it has appeared in other areas of the state, too, Tigner said.
Weeds and flowers
Q: The U.S. 11-Plantation Road corridor in North Roanoke County has two or three flower beds where local governments apparently spent money to make the area look nice, but the mowing cycles are irregular and there are weeds in the flower beds. Why haven't they followed through with maintenance?
B.D., Roanoke County
A: The state Department of Transportation said it wasn't clear which agencies were responsible for the three spots you observed.
One of them contains spring-flowering bulbs such as daffodils and day lilies, and these tend to become weedy in late summer. The weeds have been winning, obviously.
Got a question about something that might affect other people, too? Something you've come across and wondered about? Call us at 981-3118. Or, e-mail RayR@Roanoke.Infi.Net. Maybe we can find the answer.
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