Ecological correlates of pest infestation on roseroot (Rhodiola rosea), a culturally important medicinal plant

Abstract

Pests can have detrimental effects on plant populations by compromising growth, reproduction, and survival. Dryocoetes krivolutzkajae Mandelshtam (Curculionidae: Scolytinae) infests rhizomes of roseroot (Rhodiola rosea L.) in isolated areas of North America. This study documents the first record of D. krivolutzkajae for the island of Newfoundland (Canada) and investigates correlates of infestation on roseroot plants. This study examines the distribution of D. krivolutzkajae on roseroot and the relationship between infestation and plant substrate, sex, distance to the ocean, population size, biomass, and distance between sample sites. Dryocoetes krivolutzkajae is widespread across the island, found in 13/17 sites surveyed, and infestation was associated with plants with greater rhizome biomass, especially male plants. Geographically closer sites had higher proportions of infested plants. No association was found between infestation and plant substrate, distance to the ocean, or population size. Galls characteristic of eriophyid mites were also found on roseroot plants but were uncommon (3/17 sites surveyed). Because roseroot is a culturally important medicinal plant that is endangered in parts of its range, studying the effects of pests on the growth and survival of this species is important for its conservation and cultivation.