Photo from the New York State Hemlock Initiative
Here is the summer newsletter from the New York State Hemlock Initiative featuring the latest in their work combating HWA. Check out the “Eyes on Hemlocks” section to learn about HWA when it is in aestivation in the summer. Aestivation is equivalent to a summer hibernation, or prolonged summer siesta, due to hot temperatures and/or drier conditions. People commonly think that HWA has disappeared from their trees, but in fact the aestivating adelgid nymphs are still there. They are just dormant and difficult to see without a magnifying glass. During the fall, we and our partners in other states track when HWA nymphs break aestivation in order to guide our management activities, especially in the realm of biological control. In the southern Appalachians, the adelgid has remained in aestivation longer than normal this year due to an abnormally warm fall. Now that it is cooling off in western North Carolina, HWA is starting to break aestivation and produce its characteristic wool. Keep a lookout to see if you can tell when HWA breaks aestivation near you by looking for new wool!