Dyke Marsh and Beyond
Cankerworms Are Prevalent in Mount Vernon
County Survey Seeks to Determine Numbers
It’s a little dull grayish-brown bug that can devastate trees. The fall cankerworm (Alsophila pometaria) is “very prevalent” in the Mount Vernon, Huntington and Franconia areas, but not other parts of the Fairfax County, county urban forester Joan Allen recently said. No one knows why they are concentrated in the eastern part of the county at this time. This winter, county staffers are trying to determine whether fall cankerworm populations are reaching dangerous levels and where. In the past ten years, these insects have defoliated up to 5,000 acres in the Mount Vernon area. (The spring cankerworm, Paleacrita vernata, is a different species.) Cankerworm population levels were high enough in early 2012 in the Mount Vernon-Franconia area …
