Incidence of Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) in Nova Scotia, Canada Christmas tree (Pinaceae) plantations

Abstract

AbstractThe occurrence of Bursaphelenchus xylophilus (Steiner and Buhrer) (Nematoda: Aphelenchida: Parasitaphelenchidae) (pinewood nematode) in Canada prevents export of wood products, including Christmas trees (Pinaceae), to Europe. A nationwide survey in 1992 extracted B. xylophilus from mature, dead, or dying balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae), but not young, healthy Christmas trees. Three species known to harbour B. xylophilus are found in Nova Scotia, but incidence of B. xylophilus within these species is unknown. Monochamus Dejean (Coleoptera: Cerambycidae) species were collected from nine and 20 sites, in 2014 and 2015, respectively, using panel traps baited with a Monochamus lure and evaluated for the presence of pinewood nematode using molecular methods after DNA isolation. Beetles were processed for DNA isolation individually in 2014 and in batches (same species and sex from same collection site and date) in 2015. Bursaphelenchus xylophilus was recovered from all three Monochamus species (M. marmorator Kirby, M. notatus (Drury), and M. scutellatus (Say)) captured in Nova Scotia Christmas tree plantations. Percentage of beetles harbouring B. xylophilus varied with species and sex. Fourteen beetle samples were selected and sent for polymerase chain reaction sequencing. Sequencing results indicated that Bursaphelenchus xylophilus found in Nova Scotia are most similar to isolates from Canada (New Brunswick and Québec), the United States of America, and China.