Abstract The elm leaf beetle (ELB). Pyrrhalta luteola (Coleoptera: Chrysomelidae), is an introduced insect that causes considerable defoliation of urban elms throughout the United States. Twenty-eight elm species or hybrids were evaluated for susceptibility to ELB in east central Arizona. Based on defoliation estimates from 1996 - 2001, several popular hybrids developed for resistance to Dutch Elm Disease, including "Regal," "Sapporo," "New Horizon," and "Homestead" are susceptible to ELB. Ulmus parvifolia, U. japonica, U. wilsoniana, and hybrids including these parents were generally resistant to ELB.
Scanning electron microscope (SEM) analysis revealed the presence of both glandular and non-glandular trichomes on the abaxial leaf surfaces. Both glandular and non-glandular trichomes were found on resistant genotypes but only non-glandular trichomes were found on susceptible genotypes. Initial results indicate foliar nitrogen concentration was higher in susceptible than resistant genotypes.
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA