Foreign Invaders Threaten Our Forests
What’s eating our forests? Unfortunately, alien invaders are. Emerald Ash Borer, Gypsy Moth, Hemlock Woolly Adelgid and Beech Bark Disease have all invaded West Virginia’s forests. Greg Hamons, Pocahontas County’s WVU Extension Agent offers some insight into these invasions.
“The hottest topic is the Emerald Ash Borer, it’s something that we’ve started to see in West Virginia over the last few years” Hamons says. “Obviously it’s a large pest on out native Ash trees, White Ash being probably the most predominant of those. There is also Green Ash as well but White Ash is a species that people plant around their homes and have around their property as well as a large commercial timber species in the State.
This Emerald Ash Borer, a large shiny emerald green beetle, invaded America from Asia. It spreads mostly by humans moving infected wood, usually firewood, from place to place. Hamons says there have been no confirmed reports yet of this borer in Pocahontas County yet, but it is getting very close.
“We’ve recently seen activity in Fayette County, and Summers County as well that confirmed that there is Emerald Ash Borer there so (it’s) definitely in the State causing a lot of damage” says Hamons.
And the damage is horrific.
“The larva of the Emerald Ash Borer feeds on the inside of the tree, inside the bark causing it to basically girdle the tree” Hamons says. Then you will start to see woodpecker damage from them feeding on the trees trying to get to those insects inside. That’s usually the first visual indication that you actually have Emerald Ash Borer present, but by that point it’s typically too late to salvage the tree.”
There is one tell sign though.
“If you don’t see the insect or don’t see the damage you can always see the exit holes for the adult insect as they emerge from the tree, they chew their way out and there’s a real distinct D shaped exit hole coming through the bark.”
The only treatment for this Ash Borer is a systemic insecticide containing “Imidacloprid” which homeowners could use to even prevent the borer from infesting an Ash tree located perhaps in their yard; however it would be impractical to use on large stands of Ash trees.
“Fortunately the conditions haven’t been optimal the last few years for them to thrive.” Hamons says. “They actually get a virus that causes the larva stage of them to die during their feeding stage so when it’s been moist for the last few springs so the population has decreased dramatically over the last few years. They haven’t done any spraying in Pocahontas County specifically but in much of the area they haven’t done many control programs because the population has been controlled so much.”
Hamons talks about how you can recognize the Gypsy Moth larva
“The Gypsy Moth, the larvae in particular is pretty distinguishable” says Hamons. They look a lot like an Eastern Tent Caterpillar. This time of year it’s a small worm. The Gypsy moth typically will have red and black dots on their back. They don’t form a tent or anything like that. Typically you’ll see the grubs , especially during large infestations, you’ll see them crawling up and down the trunks of Oak trees. They are a species that during really heavy infestations will attack and will defoliate other species.”
“The Hemlock Woolly Adelgid is a pretty big problem” Hamons says. “Our forests aren’t predominantly Hemlock forests but you know you can find areas that are predominantly Hemlock in the area. So those areas are in pretty high danger.”
Some states to the North of West Virginia have many more Hemlock forests and will be greatly affected by this insect.
Another invader, this time from Europe and accidently introduced into Nova Scotia around 1890, is Beech Bark disease caused by the Beech Scale insect. This, like the Emerald Ash Borer, is spread mostly by humans transporting wood.
“Probably one of the biggest threats in Pocahontas County is Beech Scale and Beech Bark Disease” Hamons says. “Beech Scale is a scale insect that is feeding on the bark of American Beech trees, which is a pretty prevalent species in Pocahontas County. The feeding of the Beech Scale actually introduces the Beech Bark Disease to the tree and it’s
pretty deadly to the tree. The mortality is pretty high. Some stands I’ve been in have been 98-99% mortality on Beech trees.”
Greg Hamons emphasizes that if you suspect any of these tree threats on your property, you need to contact the local Extension Officer who will help you identify it and develop a control program.