Saturday July 25, 2009, 1:44 pm
Garlic mustard, Alliaria petiolata, got its name because its leaves, when crushed, smell like garlic. According to legend, it was brought here from Europe in the 1860s as a culinary herb, but unfortunately, it doesn’t taste very good.

Since then, this invasive weed has spread to 34 U.S. states and four Canadian provinces. It is very difficult to eradicate because its seeds can remain viable in the soil for more than 10 years. A single plant can produce hundreds of seeds, which scatter as far as several yards from the parent. Garlic mustard also releases natural substances called allelochemicals into the soil to suppress growth of other plants.

Ecologist Adam Davis, with the ARS Invasive Weed Management Research Unit in Urbana, Ill., collaborated with colleagues at Michigan State University, Cornell University, the University of Illinois and CABI in Switzerland to create a computer model to simulate the weed’s life cycle.

CABI scientists also found four Ceutorhynchus weevils as potential biocontrol agents for garlic mustard. Davis combined the feeding information of the four candidate weevils and the demographic information on garlic mustard in North America to assess each weevil’s ability to inflict damage on the weed and inhibit its growth. C. scrobicollis came out on top.

The tiny C. scrobicollis only eats garlic mustard. It feeds on the weed’s root crown, the area where nutrients are stored. This stops the flow of nutrients and water from the roots to the rest of the plant. The weevil also damages the meristem, the area where new growth takes place. As a result, garlic mustard produces fewer seeds or, in areas with high weevil populations, dies prematurely without producing any seeds.

C. scrobicollis is currently awaiting release at the University of Minnesota.

Saturday July 25, 2009, 1:48 pm
Now let's see -- have we not heard "this story" before? -- like right before the unleashed disaster!

cowboss

Saturday July 25, 2009, 4:31 pm
I have worked with some brilliant Engineers in my time and one thing that is inescapable even about our brightest scientiest is that they are all human and have a propensity to make a mistake now and again. WTF makes these people think they can outsmart Mother Nature. A lesson or two in humility would go a long ways here.

Saturday July 25, 2009, 6:15 pm
What happens to the weevils when the garlic mustard dies out? It is a better alternative to spraying man-made chemicals though. Beneficial insects are wonderful friends of any gardener. But once again this is an unnatural situation.
Thanks Cowboss

Sunday July 26, 2009, 12:16 am
Unnatural for sure.
Tx Cowboss

Sunday July 26, 2009, 3:45 am
It would be one thing if the weevils were native to N. America but Swiss weevils? Karen has a point. First you introduce one thing, it gets invasive, then you introduce its "predator" and that gets problematic... and you never get back to the original situation again!
thanks Cowboss.

Sunday July 26, 2009, 5:52 am
when we go against nature theres always trouble down the road

Sunday July 26, 2009, 5:02 pm
I hate invasive plants, One purple loosestrife is destroying all of the wetlands in Vermont. I am glad to hear that there is a biological control for this invasive weed.

Friday August 7, 2009, 8:23 am
UMMMM Interesting, Thanks for this! When you bring something that isn't in its natural "environment" normally it does take over, just want people to stop invading Mother Nature and watch what you may be carrying around on YOU so you don't have something from another State, area drop off you, and start infecting a new area. Don't know all of the technical terms and science on this one...