Identity and phylogenetic relationships of ophiostomatoid fungi associated with invasive and native Tetropium species (Coleoptera: Cerambycidae) in Atlantic Canada

Abstract

In 1999, red spruce (Picea rubens Sarg.) trees in a small area of the Halifax Regional Municipality in Nova Scotia, Atlantic Canada, were found to be infested and killed by Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae), a Eurasian species of longhorn beetle. We isolated and identified the fungi associated with T. fuscum in Halifax and compared them with ophiostomatoid fungi associated with Tetropium spp. on spruce in Europe. Ophiostoma species associated with Tetropium cinnamopterum Kirby (indigenous to and transcontinental in Canada) were also compared with those associated with T. fuscum. Strains were identified based on morphological and molecular characters. Ophiostoma piceae (Münch) Syd. & P. Syd., Pesotum fragrans Mathiesen-Käärik, and Ophiostoma tetropii Mathiesen were the most frequently isolated species. Lack of type material for O. tetropii and discrepancies between the ex-type strain of O. tetropii and its original description prompted us to lectotypify this species and designate epitype material for it. The results suggest that O. tetropii was introduced with T. fuscum from Europe into Atlantic Canada.Key words: Ophiostoma tetropii, Tetropium fuscum, molecular phylogeny, invasive species.