- The gypsy moth is expanding its range in North America and is likely to invade the Ouachita/ Ozark Highlands region sometime during this century. A previous analysis indicated that forests in this area are among the most susceptible in North America to defoliation by this insect. We used USDA Forest Service, Forest Inventory and Analysis data to evaluate forest susceptibility in the region. Susceptibility was estimated as the proportion of basal area composed of tree species preferred by gypsy moth caterpillars. Analyses were stratified by ecological land type and land ownership. Forest susceptibility is highest to the north, in the Ozark Highland's area; ca. 80 percent of the forests in this area have high to very high susceptibility to defoliation. Forest susceptibility was lower to the south in the Ouachita region. This trend in susceptibility reflects the increased pine component in southern portions of the region (pine species are not highly preferred by the gypsy moth). South of the Ozark Highlands, in the Boston and Ouachita Mountains, the lower proportion of susceptible forests is lower in land owned by the forest industry, presumably because of more intensive management of softwoods. Most forests in the Ouachita/Ozark region are susceptible to gypsy moth defoliation. Should populations become established in this area, intense defoliation could result in extensive ecological and economic consequences.
Liebhold, Andrew M.; Gottschalk, Kurt W.; Guldin, James M.; Muzika, Rose-Marie. 2004. Gypsy Moth Defoliation Potential in the Ouachita/Ozark Highlands Region. Gen. Tech. Rep. SRS-74. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 267-272