Ajax weeds driving Skico buggy
July 31, 2002
The Aspen Skiing Co. has run into a problem that’s driving it buggy.
A non-native, noxious weed called yellow toadflax has invaded Aspen Mountain and is spreading at an incredibly fast rate, according to Andy Wood, the weed manager on Ajax. It first appeared about four years ago and now dominates in quarter-acre patches around the ski area.
The Skico wants to tackle the weed without simply dumping herbicides on the ground, so they contacted Colleen Magee Jandreau of the Colorado Department of Agriculture in Palisade.
Jandreau had just what the Skico needed. She brought over a cooler Tuesday packed with 1,213 noctuid moth larvae, 82 moths and 90 stem boring weevil. They were packed in the cooler with her lunch.
Jandreau said yellow toadflax is on the top 10 list of most notorious weeds plaguing Colorado. Its stem looks similar to carrot, and it has a medium-sized yellow flower.
It was introduced to the United States as an ornamental plant from the Balkan countries. Even today it can be found in wildflower mixes. It is running rampant because its seeds are carried in numerous ways – on shoes, tires or just from spreading on the ground.
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“Once it escaped, it’s such a good competitor it out-competed native grasses,” she said.
Noxious weeds aren’t a real exciting topic, so many people ignore their environmental consequences. “A lot of people think that because they’re green, they’re no problem or because they’re pretty they are no problem,” said Jandreau.
But if let unchecked, toadflax could eventually crowd out all other vegetation on Aspen Mountain. Since nature works as a complete ecosystem, that could have ripple effects. For example, deer and elk may go elsewhere for lack of forage.
The Department of Agriculture’s insectary in Palisade assists private landowners and public land managers who request help taking on weeds. The department matches natural predators with problem weeds.
Skico environmental affairs director Auden Schendler made the call for help to the insectary with Wood’s blessing.
“The more I looked into the whole concept of dealing with weeds, I found no one approach worked,” said Schendler.
Herbicides are expensive and carry unknown effects. Pulling and whacking weeds is labor intensive. Insects cannot tackle the entire problem quickly enough.
So the Skico will try to blend solutions. Jandreau’s services and those of the insects are offered by the state free of charge.
The insects were initially imported from the Balkan countries, where they keep the toadflax in check.
But what if the cure is worse then the disease? What if the non-native insects unleashed turn out to be a bigger problem than the weed?
It won’t happen, Jandreau confidently replied. The U.S. Department of Agriculture studies insects for years and determines they won’t create some unintended consequence before certifying their use.
With assurances in hand, Jandreau and Skico staffers spread out on a patch of yellow toadflax around Gwyn’s restaurant Tuesday and sprinkled the insects on the stems and flowers.
The 82 moths were brought in simply to deposit more larvae. The moths will live only two weeks, at most, but Jandreau hopes they lay eggs before they go.
The 1,213 larvae – yes, Jandreau counted them in the lab the day before – were sprinkled onto the plants. The larvae, carried in cardboard containers like those for ice cream, were already chowing down on toadflax Jandreau packed for the trip.
The stem bore weevils could prove most deadly to the toadflax. Adult females chew holes through the side of the stem and lay eggs. The larvae chew their way down the stem once they hatch, destroying the plant.
“It’s not an instant control,” said Jandreau. The insects may or may not survive the winter. They have an excellent track record in places like Montana, British Columbia and Steamboat Springs.
Jandreau said she will return to the site in one year and use a net around toadflax to try to capture weevils and moths. With luck, signs of insects and their damage should be evident. If, after two years, insects are present, the program will be firmly established.
At best, the yellow toadflax patches will be reduced and the weed will be under control. The insects will not eliminate it. After all, nothing smart eats itself out of house and home.
[Scott Condon’s e-mail is firstname.lastname@example.org]