FEEDING AND OVIPOSITION PREFERENCES OF ADULT COTTONWOOD LEAF BEETLES (COLEOPTERA, CHRYSOMELIDAE) AMONG POPULUS CLONES AND LEAF AGE CLASSES

Feeding and oviposition preferences of adult cottonwood leaf beetles, Chrysomela scripta F., were evaluated among leaf age classes by leaf plastochron index (LPI) for six Populus clones (IS-31, NC-5260, NC-5263, NC-5264, NC-5322, NC-5334) under controlled greenhouse conditions. Significant differences among clones and leaf age classes in feeding and oviposition in both multiple-choice and no-choice tests were found. Clones NC-5264 and NC-53,34 were the most preferred for both behaviors in the multiple-choice tests. The most-preferred leaf age class for feeding was LPI 3 for both the multiple-choice and no-choice trials. In the multiple-choice oviposition tests, LPIs 3 and 4 were preferred and LPI 3 was most highly preferred in the no-choice tests. Quadratic relationships between leaf consumption and percentage of leaf consumed and leaf age class are suggested by the data from both types of tests. Direct correlations were found between leaf consumption and percentage of leaf consumed and the distribution of egg masses among the leaf age classes.