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 

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 

White Pines, Hemlocks, and Sunlight

The Blue Valley Experimental Forest (Blue Valley) lies in southwest North Carolina in the Nantahala National Forest. Located in Macon County, near the point where North Carolina meets Georgia and South Carolina, the experimental forest was established in 1964. At 1,300 acres, it is the smallest of the three experimental forests in North Carolina and the second smallest…  More 

First Release in the Carolinas of New Hemlock Woolly Adelgid Predator

On Friday last week, U.S. Forest Service scientists with the Southern Research Station and Forest Health Protection released just over 1200 Laricobius osakensis beetles on eastern hemlock trees in North and South Carolina. Reared at University of Tennessee Knoxville’s Lindsay Young Beneficial Insects Lab, the predator beetles are natural enemies of the hemlock woolly adelgid, an…  More 

Life after Hemlock: Restoring Riparian Forests in the Southern Appalachians

In the last decade, the hemlock woolly adelgid, a tiny sap-sucking insect native to Japan, has swept through southern Appalachian forests, leaving dead hemlocks in its wake. Hemlock branches no longer shade streams or tower over shrubs, and their loss has affected streamside, or riparian, forests. “Without hemlock, more sunlight reaches the forest floor,” says U.S.…  More