Impact of herbivory by cottonwood leaf beetle on three selected cottonwood clones: year 2 resultsThis article is part of a larger document. View the larger document here.
Defoliation by herbivores, especially the cottonwood leaf beetle (CLB) (Chrysomela scripta F.), is a concern in the management of eastern cottonwood. In 2003, an 8-year study was initiated to determine the impact of herbivores on three selected eastern cottonwood clones. The plantation is located near Hayti, MO, on property managed by MeadWestvaco. Each clone was planted in 100 tree plots in each of 8 blocks for a total of 2,400 trees in the study. Four of the 8 blocks (1,200 trees) were not protected from defoliation, and the remaining 4 were treated with an insecticide to control CLB and other incidental herbivores. The 8-year objective is to determine the overall losses and/or gains associated with controlling and not-controlling defoliation primarily by the CLB. During the 2003 and 2004 growing seasons, monthly height, ground-line diameter (gld) (2003), diameter at breast height (d.b.h.) (2004), and degree of defoliation were recorded and statistically analyzed. Comparisons of the results of the first 2 years of this 8-year study are presented.