Mogulones crucifer, the houndstongue root feeding weevil.  The larvae of this small dark weevil with a white cross on its back are helping to control houndstongue by feeding  in the roots. (Photo by Alycia Loomis)

As you probably know, the nasty invasive weed houndstongue (Cynoglossum officinale (Boraginaceae)) has small oval/flat seeds that stick to about everything.  I have spent countless hours combing them out of my Brittany’s fur after bird hunts (spray-on cooking oil helps but then you must bathe your dog after that…).  My father and I shot two elk one season several years ago whose head/necks were covered with houndstongue seeds.  We hunt that area often and knew of no houndstongue plants within several miles of the site.  So, we came back for three consecutive years and monitored the kill/drag site for houndstongue plants that may have started from these seeds.  Houndstongue seeds only stay viable in the soil seed bank for one-two years.  We were lucky and no new plants started.  We would have pulled and bagged them if we had found any.

Houndstongue is a Montana State designated noxious weed that us humans inadvertently brought over from Eurasia.  It is a biannual plant meaning it generally lives for just two years.  The first year it grows a basal rosette (a ring of leaves) that stores energy in a single tap root.  The second year it grows a larger rosette and uses the stored energy in its tap root to bolt (grow long stems with flowers on them), flowers, produces seeds and then dies.  

On really good sites it sometimes grows side-shoots and may live a year or two longer.  The seeds tangle in the hair of wildlife/livestock and stick to our clothing, which is how the plant spreads.  I one time pulled over 100 seeds off just my boot laces.

The Whitehall Project works with bio-control agents to help control several of the noxious weeds in Jefferson County.  

We mass rear and/or collect and redistribute agents (insects and a rust fungus) for leafy spurge, spotted knapweed, Dalmatian and yellow toadflax, Russian knapweed, and Canada thistle.  We do not have an insect for houndstongue.  However, an insect that does damage houndstongue has found its way to Jefferson County. 

This insect is the houndstongue root feeding weevil (Mogulones crucifer – we call them “mo-crews” for short).  This small dark colored weevil (with a white cross-shaped marking on its back, thus the name “crucifer”) was approved for release in Canada (not the U.S.) in 1997.  They have been working well at some houndstongue sites in Canada. 

 Some of the releases were close to the northern border and the insects have found their way into the United States and have been found in northern Washington, Idaho and Montana.  Last week we found them for the first time in Jefferson County.  We have no idea how they got here; we are just glad they have made it.  The larvae feed in the roots and do the most damage.  The adults eat holes in the leaves.  

Mo-crews are not approved for release in the United States.  They have not been approved because they have the potential to damage some of our native borages (including some threatened and endangered species) that are related to houndstongue.  It is not legal in the U.S. to move these insects and you could be fined under the endangered species act if you do.  Thankfully, the permitting process in the U.S. has been restarted with new supporting research in progress and we are hopeful mo-crews may be approved for release in 1-3 years.  

I know many of you have houndstongue on your lands.  Please be patient for a bit longer while the permitting process continues.  

Since the insect is now in-county it will not be long until it naturally spreads throughout the area  When/if it is finally approved, we will aggressively redistribute the insect throughout the area.

Up next, we will inform you about what is happening with Dalmatian and yellow toadflax.  We may also have insects available for each of these two types of toadflax next week.  Contact us during normal business hours if you are interested: Alycia Loomis: 406-565-3995 or Todd Breitenfeldt: 406-498-5236.  Also, message us from our Whitehall Biological Weed Control Facebook page.

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