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Abstract
Gypsy moth defoliation is typically observed to occur on xeric ridge tops before more mesic, lowland forest, in oak-dominated habitats in the Northeast. In subsequent years defoliation may also occur in mesic forests. What causes this pattern of defoliation? Differences in the degree of defoliation may be due to differences in the density of gypsy moth populations in these "defoliation-susceptible" and "defoliation-resistant" habitats, with higher densities on ridge tops - the "focal area hypothesis." It is also possible that ridge tops have a lower foliage biomass than mesic forests, such that the same density of gypsy moth results in a proportionately greater removal of foliage - the "foliage biomass hypothesis."
Parent Publication
Citation
Jones, Clive G. 1991. What causes the patterns of gypsy moth defoliation?. In: Gottschalk, Kurt W.; Twery, Mark J.; Smith, Shirley I., eds. Proceedings, U.S. Department of Agriculture interagency gypsy moth research review 1990; East Windsor, CT. Gen. Tech. Rep. NE-146. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 127.
