Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (168 KB)

Title: Does thinning affect gypsy moth dynamics?

Author: Liebhold, Andrew M.; Muzika, Rose-Marie; Gottschalk, Kurt W.;

Date: 1998

Source: Forest Science. 44(2): 239-245.

Publication Series: Scientific Journal (JRNL)

Description: In northeastern U.S. forests there is considerable variation in susceptibility (defoliation potential) and vulnerability (tree mortality) to gypsy moth (Lymantria dispar [L.]). Thinning has been suggested as a way to reduce susceptibility and/or vulnerability. We evaluated how thinning affected the dynamics of gypsy moth populations by experimentally thinning half of each of eight oak-mixed hardwood stands in the Central Appalachians. Population dynamics of gypsy moth were monitored using yearly counts of egg masses, numbers of larvae hatching per mass, estimates of larval density, and weekly collections of larvae and pupae which were reared to quantify mortality due to parasitoids and disease. During the 8 yr study, three stands were heavily defoliated by outbreak populations of gypsy moth, three were sprayed with pesticides accidentally, and two were not disturbed. Egg-mass densities were slightly lower in the thinned portions of the undisturbed stands, but thinning had little or no effect on gypsy moth densities in defoliated and sprayed stands. Variation in mortality of gypsy moth caused by parasitoids and disease was related to variation in egg-mass densities in the current and/or preceding years. After adjusting for the effect of gypsy moth density, thinning had no significant effect on mortality from parasitoids or pathogens. We conclude that any reduction in egg mass densities as a result of thinning is likely related to the reduction in foliar biomass, not increased natural enemy activity.

Keywords: Lymantria dispar, silviculture, survivorship, parasitism, disease

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
  • This publication may be available in hard copy. Check the Northern Research Station web site to request a printed copy of this publication.
  • Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact Sharon Hobrla, if you notice any errors which make this publication unusable.



Liebhold, Andrew M.; Muzika, Rose-Marie; Gottschalk, Kurt W. 1998. Does thinning affect gypsy moth dynamics?. Forest Science. 44(2): 239-245.


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.