Sep 13 2009
I’m back in western Pennsylvania and…
Odd-shaped purple things have been scattered across the state for months but I only learned their purpose recently – and soon they’ll disappear.
These gorgeous three-sided panels can be seen from the roadside hanging in trees or on stakes. At a distance their labels aren’t visible but their color is so beautiful and their shape so clean that I assumed the first one I saw was a decoration. Miles and days later I saw another. Was this a new fashion? More miles and days I saw a third. Rural installation art?
No, these are emerald ash borer traps strategically placed by DCNR to detect the leading edge of the emerald ash borer invasion. These Asian bugs kill ash trees and there’s no cure yet. The only way to stop them is by quarantine.
Emerald ash borers are not great travellers. They were first detected in Michigan in 2002 where they probably arrived as stowaways in wooden pallets. They would have been isolated in Michigan for a long time but humans helped them across state lines by carrying their own firewood and selling infested nursery trees. That’s how the bugs made it to Pennsylvania – in landscaping trees planted in Cranberry Township, Butler County. We’ve been under quarantine since they were found in 2007.
Foresters want to know where the bugs are going so they’ve placed these sticky panels in ash trees to trap them. The panels don’t attract the bugs long distances, just trap them if they’re already present. At the end of the growing season, DCNR will collect the traps and note the locations of emerald ash borers. Inevitably the bugs will have expanded their range so the quarantine will expand too.
By now the panels have been out there for about four months. Their colors have faded and their sides are coated in bugs but you might still catch a glimpse of one before they’re collected for study.
If the project continues we’ll see them sprout again next spring. This time I’ll know what they are.
(photo linked from this article at the University of Illinois Extension)