New Manager’s Guide for Controlling Hemlock Woolly Adelgids

An Eastern hemlock can live for 800 years, anchoring ecosystems from its roots to its branches. But a bug that’s a speck by the eye can kill these giants in just a few years. Foresters, entomologists, silviculturists, physiologists, and other experts have been working together to keep hemlock trees alive and reduce the impact of…  More 

Hemlock Woolly Adelgids & Their Predator Beetle, Laricobius nigrinus

Laricobius nigrinus is a small beetle that eats an even smaller bug – the hemlock woolly adelgid, or HWA. Since 2003, Laricobius has been used to help control HWA. But the beetle, which is native to western North America, is only active during the fall, winter and early spring. Recently, USDA Forest Service research entomologist…  More 

New Seed Orchards Installed with Camcore

Andy Whittier has collected hundreds of thousands of seeds during his 17 years with Camcore and the USDA Forest Service. Whittier regularly tests seed germination rates in order to evaluate their quality. That’s how he ended up with 1,200 Eastern hemlocks (Tsuga canadensis) in a greenhouse in Waynesville, North Carolina. The hemlocks were healthy three-year-old…  More 

A Snapshot in Time of Threats to U.S. Forests

Hemlock woolly adelgid, gypsy moth, emerald ash borer: ask any USDA Forest Service scientist which insects and diseases pose a threat to our forests, and they could probably name a baker’s dozen. A huge number of insects and diseases have the potential to negatively affect tree species in the United States. However, the danger is…  More 

Hemlock Seedlings Released from Shade

Eastern hemlock typically grows in shady environments, but its world is now infested by hemlock woolly adelgids (HWA). The miniscule sap-sucking insects can kill mature trees in less than five years. “Eastern hemlock is a shade-tolerant species,” says USDA Forest Service research entomologist Bud Mayfield. “But extra sunlight may help it survive HWA infestation.” Extra…  More 

A Hemlock in the Town Square

This summer, I joined USDA Forest Service scientist Andy Whittier for a day of field work as a part of my internship with SRS Public Affairs and Science Communications. We traveled to Green Mountain, NC to check up on an experiment led by research entomologist Bud Mayfield on hemlock trees. Throughout the eastern U.S., the invasive…  More 

Conserving Eastern Hemlock

Where can you go to find an eastern hemlock tree? Although threatened by the hemlock woolly adelgid, eastern hemlock has an extensive range. “Eastern hemlock grows throughout the southern Appalachians,” says U.S. Forest Service collaborator and ecologist Kevin Potter. Potter is also a forestry faculty member at North Carolina State University. “Hemlock grows in the…  More 

Hemlock Seed Banking

Eastern and Carolina hemlock trees in more than 400 counties across 19 states are dead, dying, or threatened by infestation of the invasive hemlock woolly adelgid. As the aphid-like pest continues to spread throughout the ranges of these economically and ecologically important trees, scientists, managers, and other specialists from North Carolina State University’s (NCSU) Camcore…  More 

Sunlight vs. Hemlock Woolly Adelgids

Scientists have identified a potential new strategy for protecting hemlocks from the miniscule insect that plagues them. “High levels of sunlight help reduce hemlock woolly adelgid abundance on young seedlings,” says U.S. Forest Service project leader Bud Mayfield. “Follow-up experiments in the field are still needed, but the results suggest thinning or strategically creating gaps…  More 

Sap-sucking Bugs Threaten Hemlock Forests

Sap-sucking insects called hemlock woolly adelgids are draining the life from a common evergreen tree in the eastern United States. Since arriving from Japan in the 1950s, the tiny bugs have spread from Georgia to Maine—about half of the Eastern hemlock’s range. Once the bugs become well-established, the consequences can be grave. Areas with severe…  More