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Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae), an invasive phloem-feeding pest, was identified as the cause of widespread ash (Fraxinus) mortality in southeast Michigan and Windsor, Ontario, Canada, in 2002. A. planipennis reportedly colonizes other genera in its native range in Asia, including Ulmus L., Juglans L., and Pterocarya Kunth. Attacks on nonash species have not been observed in North America to date, but there is concern that other genera could be colonized. From 2003 to 2005, we assessed adult A. planipennis landing rates, oviposition, and larval development on North American ash species and congeners of its reported hosts in Asia in multiple-choice field studies conducted at several southeast Michigan sites. Nonash species evaluated included American elm (U. americana L.), hackberry (Celtis occidentalis L.), black walnut (J. nigra L.), shagbark hickory [Carya ovata (Mill.) K.Koch], and Japanese tree lilac (Syringa reticulata Bl.). In studies with freshly cut logs, adult beetles occasionally landed on nonash logs but generally laid fewer eggs than on ash logs. Larvae fed and developed normally on ash logs, which were often heavily infested. No larvae were able to survive, grow, or develop on any nonash logs, although failed first-instar galleries occurred on some walnut logs. High densities of larvae developed on live green ash and white ash nursery trees, but there was no evidence of larval survival or development on Japanese tree lilac and black walnut trees in the same plantation. We felled, debarked, and intensively examined >28 m2 of phloem area on nine American elm trees growing in contact with or adjacent to heavily infested ash trees. We found no sign of A. planipennis feeding on any elm.

New infestations of emerald ash borer, Agrilus planipennis Fairmaire, an invasive pest native to Asia, are difficult to detect until densities build and symptoms appear on affected ash (Fraxinus spp). We compared the attraction of A. planipennis to ash trees stressed by girdling (bark and phloem removed from a 15 cm wide band around the tree (2003)(2004)(2005)), vertical wounding (same area of bark and phloem removed in a vertical strip (2004)), herbicide treatment (Pathway applied with a Hypo-Hatchet tree injector (2003) or basal bark application of Garlon 4 (2004Garlon 4 ( , 2005), exposure to the volatile stress elicitor methyl jasmonate (2005), or left untreated (2003-2005). The number and density of captured adults and density of larvae were recorded for 24, 18, and 18 replicates of each treatment at four, three, and five sites in 2003, 2004, and 2005, respectively. Girdled trees generally captured more adult A. planipennis and consistently had higher larval densities than untreated trees, and at most sites, than trees stressed by other treatments. Differential attraction to girdled trees was more pronounced at sites with lower densities of A. planipennis. Rates of capture of adults and densities of larvae were higher on trees in full or nearly full sun than on shaded trees. Girdled trees could be a useful tool for use in operational programs to detect or manage localized A. planipennis infestations.Résumé : Les nouvelles infestations de l'agrile du frêne, Agrilus planipennis Fairmaire, un ravageur invasif, indigène de l'Asie, sont difficiles à détecter jusqu'à ce que la densité de l'insecte augmente et que les symptômes apparaissent sur les frênes (Fraxinus spp.) infestés. Nous avons comparé l'attirance d'A. planipennis pour des tiges de frêne stressées par une annélation (bande d'écorce et de phloème de 15 cm enlevée autour de la tige de 2003 à 2005; une blessure verticale (bande verticale d'écorce et de phloème enlevée sur une surface équivalente (2004)); l'application d'un herbicide (Pathway appliqué avec une hachette injectrice (2003)); l'application de Garlon sur l'écorce à la base du tronc (2004)(2005)); l'exposition au jasmonate de méthyle, un éliciteur de stress volatil (2005) et pour des tiges non traitées (2003 à 2005). Le nombre et la densité des adultes capturés ainsi que la densité des larves ont été notés pour 24, 18 et 18 répétitions de chaque traitement à quatre, trois et cinq endroits respectivement en 2003, 2004 et 2005. Les tiges annelées ont permis de capturer généralement plus d'A. planipennis adultes et avaient une densité de larves constamment plus élevée que les tiges non traitées et, à la plupart des endroits, que les arbres stressés par les autres traitements. L'attirance pour les tiges annelées était plus prononcée aux endroits où la densité d'A. planipennis était plus faible. Les captures d'adultes et la densité des larves étaient plus élevées sur les arbres exposés au plein soleil ou presque que sur les arbres ombragés. Des arbres annelés pourraient être un outil utile dans le...

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