Resistance of ulmaceae to feeding by the adult elm leaf beetle (Coleoptera: Chrysomelidae)
AbstractFifteen Ulmus and one Zelkova taxa were evaluated in no-choice and multiple-choice laboratory bioassays for their preference and suitability for the adult elm leaf beetle (ELB), Xanthogaleruca luteola (Muller). Suitability of each taxon was defined by the mean number of eggs laid per female and the mean percentage of females ovipositing in no-choice laboratory feeding studies. Preference for each taxon was defined by the percentage of leaf tissue removed in multiple-choice laboratory feeding studies. Adult females laid significantly more eggs on U. canescens and U. pumila, highly preferred hosts, and the cultivar U. 'Morton Stalwart' CommendationTM, indicating their greater suitability for the ELB. Male and female longevity was similar for all taxa tested in this study, with both sexes living approximately 5 ± 3 days. Adult longevity was not correlated with suitability. Results from the multiple-choice feeding preference studies somewhat followed the suitability rankings in the no-choice feeding studies for the same taxa, with taxa that were less suitable in the no-choice studies being less preferred in the multiple-choice studies. The reverse is also true. As observed in this study and previous studies, preference and suitability increases when U. pumila is included as part of the parentage of simple complex hybrids. Of the 16 taxa evaluated in this study, U. canescens, U. pumila, and U. 'Morton Stalwart' Commendation appear to be more suitable for feeding and reproduction by adult ELBs, limiting their use in landscape and urban forest plantings where chronic ELB outbreaks are common. The North American and European elm taxa of U. alata, U. americana, and U. foliaceae, simple hybrids consisting of U. japonica and U. wilsoniana parentage, and Z. serrata appear to be less preferred and less suitable for reproduction.
Volume, Issue, Page Number29, 2, 98-103