Council issues recommendations on houndstongue control

Press release

HELENA — The Montana Invasive Species Council issued recommendations Tuesday to guide the potential for approval of the weevil Mogulones crucifer for classical biological control of houndstongue in the U.S.

Houndstongue is a state noxious weed that is impacting land managers of private and public land across Montana inlcuding this region of north-central Montana. It is a major problem in Beaver Creek Park south of Havre.

In April 2019, MISC hosted a Science Advisory Panel to:

1. evaluate the feasibility of gaining approval to release M. crucifer for biological control of houndstongue in the U.S. by reviewing information available subsequent to its approval for release as a biological control agent in Canada;

2. identify USDA APHIS and USFWS ecological criteria that will be used to determine the safety of releasing M. crucifer as a biological control agent in the U.S .; and

3. provide input and guidance to managers if the organism is encountered in the field.

“The panel was a successful step in the process of moving forward towards a successful petition for the release of M. crucifer,” said MISC Chair Bryce Christiaens. “This root weevil is an approved biological control agent in Canada and has proved to be very effective in controlling houndstongue in Alberta and British Columbia.”

Canada began releasing the biological control agent Mogulones crucifer, a weevil, in 1997 for the control of houndstongue, a highly invasive nonnative weed that is a serious issue for ranchers and outdoor enthusiasts. The weevil has had lasting population level impacts on houndstongue in Alberta and British Columbia. While these weevils have naturally moved into Montana from Canada, they are not an approved agent in the United States. It is currently illegal to facilitate their redistribution through non-natural means due to the unapproved status, plus concerns that these weevils may feed on federally protected non-target plant species.

Considering the absence of other effective control methods for houndstongue, along with the lack of negative ecological impacts and positive management outcomes associated with the release of this agent in Canada, the Montana Invasive Species Council enlisted assistance from the scientific community and formed a science advisory panel to evaluate the feasibility of approving and using Mogulones crucifer in the U.S. by reviewing new or additional information available since its approval and introduction in Canada.

The panel included biocontrol scientists and researchers, as well as representatives from USDA-APHIS, the permitting agency, and the U.S. Fish & Wildlife Service for a two-day workshop. Christiaens said the Council’s recommendations were developed from the input of the panel.

Key findings and a complete summary of the recommendations can be found at http://misc.mt.gov .