Knowledgebase

Do you have or know where I can acquire spotted knapweed weevils? #936572

Asked June 23, 2026, 5:19 PM EDT

My name is Lauren, and I am the Invasive Species Coordinator, working in the Northeast with the U.S. Fish and Wildlife Service. Missisquoi NWR is interested in using spotted knapweed weevils to help control the spotted knapweed on the refuge that are infiltrating their pollinator gardens. Do you know of anyone who is doing this bio control and the extent of it? Is it possible to help treat spotted knapweed in our refuge with this biocontrol? Thank you!

Franklin County Vermont

Expert Response

Hello Lauren and thank you for reaching out to the UVM Extension Master Gardener Helpline with your questions about managing spotted knapweed with a biological control. As an invasive species coordinator, I'm sure you are aware of the resources available from Vermont Invasives, https://www.vtinvasives.org/invasive/spotted-knapweed.

It is my understanding that introducing a biological control species like Cyphocleonus achates into Vermont would require state and federal regulatory permissions, eg., a biological control organism permit from APHIS, etc. These agencies help ensure that we are not introducing a future problem, right?

I would be happy to provide you with some contacts at the Vermont Agency of Agriculture and Agency of Natural Resources if you'd like. 

Happy Gardening! Replied June 24, 2026, 12:28 PM EDT

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