The presence of the emerald ash borer, a green beetle native to Asia, has been confirmed in Ulster County. New York has 900 million ash trees, representing about 7% of all trees in the state. Since 2002, the emerald ash borer has killed 70 million ash trees in 13 mid-western states and Pennsylvania. It spreads 15-20 miles per year. Ash is a critical riparian tree; a recent survey found that over half of the trees along the Mohawk River are ash. If the emerald ash borer grabs a foothold in New York, one could conclude that where ash is present in riparian forests at high densities you'll likely see some impacts to streams such as increases in water temperature.
As of a few days ago, it was discovered in 13 locations throughout the county (read about it here). This is really bad news. The emerald ash borer (Agrilus planipennis ) is a metallic green beetle only about 1/3 of an inch long (8.5 mm). Beetles lay their eggs in crevasses in the bark and the larvae burrow into the tree and form a network of tunnels as they consume the cambium and phloem tissues beneath the bark. This eventually girdles the tree and kills it.
If you want to check trees in your area, here's a guide to identfying ash (Fraxinus sp.) trees and how to tell them apart from similar species. Here's a guide to signs of emerald ash borer infestation. If you find these beetles, report them to the phone numbers in this Times Herald-Record article.
The emerald ash borer came from China to Michigan in 2002 and has since spread to 14 eastern states. Invasive pests like this are why you're asked not to transport firewood from place to place (when camping, for example). You can easily introduce a new pest into an uninfected area and that's likely how it got into our area. It's best to buy and use firewood locally.
By the way, The Hudson River Almanac is a wonderful email bulletin of nature sightings in the Hudson River and environs. Highly recommended for those interested in what other people are spotting locally.
The Hudson River E-Almanac is compiled and edited by Tom Lake and emailed weekly by DEC's Hudson River Estuary Program. To sign up to receive the E-Almanac (or to unsubscribe), send an email message to email@example.com and write E-Almanac in the subject line.