Forest Habitat Characteristics Associated with Simplocaria metallica (Sturm) and Other Pill Beetle Species (Coleoptera: Byrrhidae) in Northern Alberta, Canada

Despite close and potentially interesting associations between pill beetles (Coleoptera: Byrrhidae) and bryophytes on which they are obligate feeders, little is known about byrrhid ecology in Canadian forests. To determine the extent to which boreal forest stands support populations of pill beetles, we established a systematic sampling grid of 200 sampling sites covering 82 km2 of boreal mixedwood forest in northwestern Alberta. We found that byrrhid species, especially Simplocaria metallica (Sturm), occur in association with stands of small black spruce (Picea mariana (Mill.) BSP; Pinaceae) subject to frequent disturbances. The habitat occupied by black spruce in this part of the boreal forest also includes potential bryophyte hosts of several pill beetle species. Our findings suggest that pill beetles can be used as indicators of disturbances such as fire, harvest, gravel pit construction, and road ditching. They seem to flourish in frequently disturbed forested habitats such as peat bogs and taiga forest that provide arid environmental conditions similar to arctic or alpine environments.