Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Andrew M. Liebhold; Rose-Marie Muzika; Kurt W. Gottschalk
    Date: 1998
    Source: Forest Science. 44(2): 239-245.
    Publication Series: Scientific Journal (JRNL)
    Station: Northern Research Station
    PDF: Download Publication  (167.94 KB)


    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.

    Publication Notes

    • 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.
    • 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.


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


    Lymantria dispar, silviculture, survivorship, parasitism, disease

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page