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ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Publications at this Location » Publication #422169
Research Project: Discovery and Development of Microbial-Based Biological Control Agents for Use Against Invasive Weeds in the United States

Location: Foreign Disease-Weed Science Research

Title: The History and Ecology of Common Crupina Biocontrol Agents in North America

Author
item Tancos, Matthew
item West, Natalie
item ANDREAS, JENNIFER - Washington State University

Submitted to: North American Invasive Species Management Association (NAISMA)
Publication Type: Other
Publication Acceptance Date: 1/15/2025
Publication Date: 1/15/2025
Citation: Tancos, M.A., West, N.M., Andreas, J.E. 2025. The History and Ecology of Common Crupina Biocontrol Agents in North America. North American Invasive Species Management Association (NAISMA). https://doi.org/10.1094/PHYTOFR-10-23-0138-SC.
DOI: https://doi.org/10.1094/PHYTOFR-10-23-0138-SC

Interpretive Summary: Peer-reviewed biological control factsheets developed and published by The North American Invasive Species Management Association for managers and landowners. This factsheet looks at the invasive weed, common crupina, and the approved fungal biocontrol agent, Ramularia crupinae. These weed/biocontrol agent factsheets provide vital information concerning common crupina identification, habitat distribution, ecology, similar looking plant species, approved biocontrol agents, identification of biocontrol agents, and the impact of biocontrol agents.

Technical Abstract: Common crupina is native to Europe, Asia, and northern Africa. It was first discovered in Idaho in 1968, and is hypothesized to have been inadvertently introduced by Basque shepherds and their herding dogs beginning in the 1930s. It is now established in four western states with a few, non-confirmed sightings in West Virginia and Massachusetts(Fig. 1). Western populations consist of two different varieties, which can be distinguished genetically as well as morphologically. Variety brachypappa is present in Washington and Modoc County, California while variety vulgaris is present in Idaho, Oregon, and Sonoma County,California. As of 2024, this species has not been reported in Canada. Common crupina creates dense infestations that displace desirable forage species and contaminate hay. When common crupina replaces fibrous-rooted grass species, there is an increased risk of soil erosion. In some native ecosystems in the Northwest, common crupina infestations have reduced biodiversity. Ramularia crupinae is a biological control agent approved in the USA for release against common crupina.This fungus overwinters in debris from infected plant parts or on cotyledons of young seedlings as light to dark brown lesions that are irregular to round in shape. These spread to infect true leaves and stems in spring.