MORE THAN 10 years ago, Ben Puttler, when he worked for the USDA Biological Control Lab in Columbia, campaigned for research funding for introducing biological control for teasel, a weed pest introduced from Europe.

The teasel life cycle is very similar to the musk thistle, which is now being effectively controlled by weevils introduced from Europe. But, he was repeatedly turned down. “I was told there is no political support for teasel control,” he said.

Now teasels are widely spread along Missouri highways. The common teasel and the cut-leaf teasel have been added to the state noxious weed list by the Missouri General Assembly this year. But as yet, there is still no research on biological control.

“It would take five to 10 years to test and develop a biological control,” Puttler said. “The teasels have natural controls in their native regions.” It would require searching in the teasel's native area to find natural enemies of the weed. Then it would require determining the insects that are host-specific and safe to release here.