Interactive Map of Idaho >> Region 1 - Northern Idaho >> Yellow Starthistle Panorama >> Starthistle Biocontrol Agents Video

Starthistle Biocontrol Agents Video                               

Art Talsma and TNC crew pound a stake to establish the long term photo point and use a net to begin gathering biocontrol bugs. Art notes that "This is nasty stuff to walk through, even at this time of year, and the spines just get harder and harder."

The study crew deposit the contents from the net onto a white fabric and begin to count and describe the "Peacock Fly" which lay their larvae on the Yellow Starthistle seed head. The peacock fly is mobile and can get around to different plants but they don't control the seeds by themselves.

Next they look at and describe the major biocontrol agent for Yellow Starthistle. They are very plant specific. The specie Eustenopis villosus seems to be the most effective. They actually feed on the seed head after the Yellow Starthistle goes into flower. The seed head will essentially abort and not produce any viable seed. To get each biocontrol agent into the United States from their native habitat in Eurasia may take 5 science years of study and cost 1/4 to 1/2 million dollars, before they are allowed to be released here. Of course they study them especially on their effect on agricultural crops, but also on other native plants in controlled situations. It is a fairly high cost initially, but a very low cost to maintain. Once they start to reproduce, the idea is that then you won't have to use herbicides and you get some control over the plants, bringing them back into balance, because these are the natural predators on the plant over in Europe where the plant came from.

More Yellow Starthistle Video Sequences Found in the Panorama

• Identifying biocontrol weevil and larvae
• Discussing the transition between native bunch grasses and encroaching starthistle