Average (±SE) percentage of bumble bees (sexes and castes pooled) infected by <i>Crithidia bombi</i> among the most common <i>Bombus</i> species at our study sites in southern Ontario during June–August, 2005.

Average (±SE) percentage of bumble bees (sexes and castes pooled) infected by Crithidia bombi among the most common Bombus species at our study sites in southern Ontario during June–August, 2005.