Tuesday, December 11, 2001 -
D0403

Does leaf morphology constrain feeding rates and food choice in the imported willow leaf beetle?

Michael Raupp1, Kreshnik Bejleri1, and Neda Diab2. (1) University of Maryland, Department of Entomology, 4112 Plant Sciences Building, College Park, MD, (2) University of Maryland, Department of Nartural Resource Sciences and Landscape Architecture, Plant Sciences Building, College Park, MD

The Imported Willow Leaf Beetle, Plagiodera versicolora (Laicharting), feeds on willows and poplars in the eastern United States. Adults feed primarily on young leaves and lay eggs on older ones. Consequently, larvae, particularly early instars, consume mature foliage. Comparisons of feeding behaviors of adults and larvae revealed that larvae and adults respond to variation in leaf age in different ways. Phytochemical analyses indicated that leaf moisture content was the best predictor of feeding rate for all larvae stages but leaf toughness explained most of the variation in feeding rates for adults. Leaf nitrogen, condensed tannin content, and total phenolic content were less strongly correlated with feeding rates for all stages. Morphological analyses of willow leaves and beetle jaws indicated that vascular tissues interfere with mastication in adults more so than larvae. Larvae encounter veins less frequently due to their smaller size and may be exploit a larger variety of leaf age classes than adults. Leaf morphology may seriously limit leaf consumption and thereby constrain food choice in adult beetles.

Species 1: Coleoptera Chrysomelidae Plagiodera versicolora (imported willow leaf beetle)
Keywords: Herbivory, Niche selection

The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA