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Two breeding populations of the non-native Asian longhorned beetle (Anoplophora glabripennis Motschulsky), a pest of broadleaf trees in its native China, were discovered in Ontario in 2003 and 2013, respectively. Both populations were eradicated by removing all trees injured by the beetle and all uninjured trees deemed at high risk of injury. We used data collected during this removal to study host selection. Signs of A. glabripennis injury were observed on 732 stems from seven (i.e., Acer, Salix, Populus, Betula, Ulmus, Fraxinus, and Tilia) of the 45 tree genera available. Complete beetle development was confirmed on only the first four of these seven genera. Most signs of injury were on the genus Acer and on trees with a diameter at 130 cm above ground ranging between 15 and 40 cm. On most trees, the lowest sign of injury was within 3 m of the ground or within 40% of tree height. Tree height explained 63% of the variance in the location of the lowest sign of injury. Initial attacks were typically near the middle of the tree and expanded both upward and downward with successive attacks over time. We discuss how these findings could improve survey efforts for A. glabripennis. Key words: Asian longhorned beetle, host availability, host range, Acer, forest invasive alien pest, urban forest pest, exotic, eradication. Deux populations reproductrices non indigenes du longicorne asiatique (Anoplophora glabripennis Motschulsky), un ravageur des essences feuillues en Chine d'ou il est originaire, ont ete decouvertes en Ontario respectivement en 2003 et 2013. Les deux populations ont ete eradiquees en eliminant tous les arbres endommages par le longicorne et tous les arbres non endommages mais juges a risque de l'etre. Nous avons utilises les donnees collectees lors de cette intervention pour etudier la selection de l'hote. Des signes de degats causes par A. glabripennis ont ete observes sur 732 tiges appartenant a sept (c.-a-d. Acer, Salix, Populus, Betula, Ulmus, Fraxinus, et Tilia) des 45 genres d'arbres pouvant servir d'hotes. Le developpement complet de l'insecte n'a ete confirme que sur les quatre premiers de ces sept genres. La plupart des signes de degats ont ete observes sur le genre Acer et sur des arbres dont le diametre a 130 cm au-dessus du sol mesurait entre 15 et 40 cm. Sur la plupart des arbres, le signe de degat le plus bas etait situe a moins de 3 m du sol ou 40% de la hauteur de l'arbre. La hauteur de l'arbre expliquait 63% de la variance de la localisation du signe de degats le plus bas. Les attaques initiales etaient typiquement situees pres du milieu de l'arbre et s'etendaient avec le temps vers le haut et vers le bas a la suite d'attaques successives. Nous discutons de la facon dont ces resultats pourraient ameliorer les efforts d'inventaire de A. glabripennis. [Traduit par la Redaction] Mots-cles : longicorne asiatique, disponibilite des hotes, aire de repartition des hotes, Acer, ravageur forestier exotique invasif, ravageur forestier en milieu urbain, exotique, eradication., Introduction A large proportion of non-native terrestrial arthropods that arrive in Canada feed on woody plants (Langor et al. 2009). One of these alien invasive species is the Asian longhorned [...]

Adelges tsugae Annand (Hemiptera: Adelgidae), a nonindigenous insect pest of hemlock (Tsuga spp.) (Pinaceae) in eastern North America, spends most of its life cycle within an ovisac, which resembles a woolly white mass on twigs. We evaluated the probability of detecting adelgid wool with Velcro®-covered balls when taking an increasing number of samples per tree (field sampling) and number of trees per simulated stand. We examined the relationship between the detection of adelgid wool using this technique and the incidence of A. tsugae-infested twigs by sampling lower-crown branch tips of the same trees. We found that the probability of detecting wool with ball sampling increased with number of ball samples per tree, with number of trees per simulated stand, and with increasing incidence of ovisacs in the lower crown. When sampling an individual tree, we found that 20 ball samples per tree achieved a targeted precision level of 0.75, but when sampling a stand, we found that 10 ball samples per tree took the least time for the range of simulated A. tsugae infestations we tested. These sample sizes are recommended for detection of A. tsugae infestations on an individual tree and in a hemlock stand. [ABSTRACT FROM AUTHOR]