Scientists & Staff

Andrew Liebhold

Andrew Liebhold

Research Entomologist
US Forest Service Northern Research Station
180 Canfield St.
Morgantown, WV, 26505
Phone: 304-285-1512

Contact Andrew Liebhold

Current Research

Population biology of biological invasions

Much of my research focuses on understanding ecological processes operating during the arrival, establishment, and spread phases of biological invasions. In particular, I am interested in understanding these processes as the basis for more effective strategies to exclude invaders, prevent establishment (eradication) and contain the spread of invading forest pests. This work includes studies on the gypsy moth, Sirex woodwasp, beech bark disease, Japanese oak wilt disease, emerald ash borer and hemlock woolly adelgid.

Forest insect population dynamics

I am interested in understanding the processes that are responsible for the spatial and temporal patterns of forest insect outbreaks. Many insect species exhibit periodic population oscillations that occur synchronously over large areas but we have only a partial understanding of the population processes (interactions with predators, parasitoids, host plants and disease) that cause these patterns. Analyses of historical data and mathematical models are applied to explore these relationships. This work focuses on the gypsy moth, but includes several other forest insect species as well.

Why This Research is Important

North America is currently experiencing an onslaught of invasions by damaging forest pest species. We need to develop more effective strategies for mitigating this problem. Unfortunately, there are often few options for preventing or minimizing the impacts of these invasions but the development of a clearer understanding of the invasion process is critical for the development of more effective management strategies.

Forest insect outbreaks have a multitude of ecological and economic impacts but currently we have a very limited ability to either predict or prevent such outbreaks. Knowledge of the underlying processes that generate outbreaks is critical for improving our ability to forecast and manage outbreaks in the future.


  • University of Massachusetts, Postdoctoral , 1988
  • University of California at Berkeley, Ph.D. Entomology, 1984
  • Allegheny College, B.S. Biology, 1978

Professional Organizations

  • West Virginia University
  • Invasive Species Specialist Group (ISSG). World Conservation Union (IUCN)
  • IUFRO Research Group 7.03.00, Entomology
  • Carnegie Museum of Natural History, Pittsburgh, PA
  • Population Ecology
  • Ecology Letters
  • Biological Invasions
  • The Pennsylvania State University

Awards & Recognition

  • US Forest Service Distinguished Scientist Award, 2022
  • Clavariate Web of Science Highly Cited Researcher, 2022
  • Fellow, Entomological Society of America, 2021
  • International Union of Forest Research Organizations Forest Health Achievement Award, 2019
  • Fellow, American Association for the Advancement of Science (AAAS), 2015
  • Lifetime Achievement Award, National Gypsy Moth Management Board, 2011 Lifetime Achievement Award, National Gypsy Moth Management Board
  • Sustaining Forests and Grasslands Award, Northern Research Station , 2011 (co-recipient)
  • Scientific Achievement Award, International Union of Forestry Research Organizations, 2010 IUFRO
  • Distinguished Science Award, Northeastern Research Station, 2006 Distinguished Science Award, Northeastern Research Station
  • Forest Insect and Disease Resesarch Award, Forest Insect and Disease Research, USFS Headquarters, 1994 Forest Insect and Disease Resesarch Award, Forest Insect and Disease Research, USFS Washington Office
  • Director's award for research excellence, Northeastern Forest Experiment Station, 1994 Director's award for research excellence, Northeastern Forest Experiment Station

Featured Publications & Products

Publications & Products

National Research Highlights

Red pines (Pinus resinosa) killed by the red pine scale (Matsucoccus matsumurae) near Myles Standish State Forest, Massachusetts. Photo by Jeff Garnas[MOU1] , University of New Hampshire.

A Tree Species’ Evolutionary History Predicts Impact of Invasive Pests

Year: 2020

Research by Northern Research Station scientists and their partners presents the first evidence supporting a long-held hypothesis that a tree’s evolutionary history is key to its susceptibility to nonnative herbivorous insects. This discovery has the potential to be a game-changer in predicting the impact of and managing nonnative insects.

Nonnative Invasive Insects and Diseases Decreasing Carbon Stored in U.S. Forests

Year: 2019

Photosynthesis feeds trees and has a significant benefit for people, too, namely the removal of carbon from the atmosphere and into live tree biomass through a process called “sequestration.” But USDA Forest Service scientists and a colleague found that increased tree mortality from the impacts of nonnative insects and diseases results in the transfer of carbon stored in live trees into dead material, much of which will eventually return to the atmosphere by decomposition. This threatens the estimated 76 percent of carbon sequestration in North America that comes from forests.

Predicting pest invasions

Year: 2017

During the last 150 years, hundreds of forest insects have been accidently introduced to the U.S., and many of these have caused substantial damage. The potential for new insect invasions remains as global trade continues to expand. Forest Service scientists and their partners developed a model to incorporate sizes of source species pools and trade volumes to predict the numbers of new forest insect species likely to invade in the future.

Comparing number of non-native and native species. Sandy Liebhold, U.S. Department of Agriculture Forest Service.

Comparison of Native and Non-native Insect Communities Reflects Importance of Pathways

Year: 2016

Insect species are accidentally moved around the world and often cause considerable damage when established. An analysis of insect invasions worldwide demonstrates that the mechanisms by which insects are transported plays a key role in selecting which type of species invade new regions.

Last modified: Friday, January 27, 2023