Poplar Clonal Preferences of the Cottonwood Leaf Beetle12

Abstract

The relative susceptibilities of 33 poplar clones to Chrysomela Scripta F. were measured in 1977 during a season of heavy infestation of this insect in a clonal orchard at Ames, Iowa. Damage to trees was estimated by using the criteria of shoots no longer usable for cuttings and leaf area lost to beetle feeding. Of the 3 clones showing little or no damage in either category, 2 had Populus alba L. parentage. Other than P. alba, parentage had little influence on beetle preference. Although most clones resumed growth during the season, shoot height growth was reduced as much as 80% in severely defoliated clones.