Learn About Whitehall Bio Control: 6/5/2024

The Whitehall Biological Weed Control Project of the Jefferson County Weed District has already started up in a small way this spring.

We hired an Americorp MCC Conservation Intern, Ava Frans, from Walla Walla, Washington, who will work with the crew until mid-August. She is a sophomore at Whitman College majoring in Environmental Science and Biology. We also have returning college student Brynna Wolfe (who has worked several years for the Whitehall Project) splitting her time helping Jill Allen (the County Weed Coordinator) and the Whitehall Project. The four high school students hired will start about June 11th and will be introduced in a later article. Todd Breitenfeldt, retired WHS science teacher, has been the Whitehall Project Coordinator since 1993 and continues today.

Last week, we made the first release of a new bioagent for whitetop (hoary cress) in our area. This agent has only been released in Montana for five years, and we are very pleased to have been selected for these releases. We will be asking for your help in identifying new potential future release sites as this agent becomes established, and we can redistribute them throughout our area. These sites need at least several acres of scattered whitetop and cannot flood or be heavily grazed, especially when the plant is blooming in spring and early summer. The sites should also be contiguous to other whitetop infestations so the agent can disperse.

This whitetop bioagent is a microscopic mite (Aceria drabae) specifically from northern Greece. They produce galls (swellings) in the flowers and upper stems that resemble little heads of broccoli to larger deformities. These galls prevent the plants from going to seed. The galls also are formed on the secondary stems and weaken or stunt the plant. The mites don't kill the plants but slow the spread and weaken them. If you have a potential whitetop mite release site, please call Todd during normal business hours at 406-498-5236 or Jill at 406-225-4165.

We also have yellow toadflax stem mining weevils (Mecinus janthinus) available in small numbers from our insectary at Whitehall High School. These weevils (beetles) are becoming an effective bioagent. They are greatly reducing yellow toadflax in many areas of the state to the point where we are having trouble finding good collection sites for this insect. If you have yellow toadflax (Linaria vulgaris), feel free to give us a call and we will be glad to come on out and monitor your land to see if it is a good candidate for a release. These great little weevils should be available for another few weeks.

As the summer progresses, we will have insects for Dalmatian toadflax (late May and June), leafy spurge (late June and July), and spotted knapweed (late July and August. We may also have some Canada thistle fungus available in late September.

We offer many educational workshops, seminars, and talks to groups of all ages and interests about controlling noxious weeds, with an emphasis on biocontrol. If your group would like to schedule a talk, give us a call.

Remember, the time to start managing the noxious weeds on your land is TODAY! Make a plan and carry it out!!