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 

White Oak Regeneration in Canopy Gaps

In February 2020, USDA Forest Service scientist Stacy Clark planted 720 white oak (Quercus alba) seedlings on the Pisgah National Forest in western North Carolina. “White oak is declining in abundance across the eastern U.S., and we are concerned that wildlife species and industries around cooperages, distilleries, and flooring will be negatively affected without proactive…  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 

How Tree Diversity Affects Invasive Forest Pests

“Invasive insects and diseases pose both ecological and economic threats to our forest ecosystems,” says Qinfeng Guo, USDA Forest Service research ecologist. Guo is the lead author of a broad-scale study of U.S. forest data that examines the relationship between the number of native tree species and the number of nonnative forest pests. Across their…  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 

Carolina Hemlock Populations: Isolated and Imperiled

Hemlocks are under attack. U.S. Forest Service scientists and their partners are working to save the native conifers from the hemlock woolly adelgid (HWA), an invasive insect from Japan. Carolina hemlock (Tsuga caroliniana) trees can survive HWA infestation for a decade or more but often die within four years. Carolina hemlocks grow in tiny, isolated…  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