This page contains a Flash digital edition of a book.
feeding beetle, used to attack the toxic agricultural weed, St. Johns-wort. Less than 10 years after the beetle's release St. Johns-wort was under control throughout most of its range in the province.


Tansy ragwort, another agricultural weed that causes liver damage to livestock when ingested and taints honey with a bad taste when used by honey bees, is under the control of several biocontrol agents: a leaf-eating moth, a seed-eating fly, a root-feeding flea beetle, and a root-feeding moth. Biological control agents have since been released for diffuse and spotted knapweed, Canada thistle, leafy spurge, dalmatian and yellow toadflax, hound's tongue, and scentless chamomile. The most recent release was conducted just this summer. Aulacidea subterminalis, a stolon-tip attacking gall wasp, will work on bringing orange hawkweed under control in the Interior of the province.


Currently research is being conducted in the U.K. on agents that could be used for the dreaded Japanese knotweed. In Japan, where knotweed is native, there are approximately 168 insect species and 40 fungi species that


keep it under control. Here it has none. Knotweed, which is considered hazardous waste in the U.K., is also a huge problem in the Fraser Valley and Lower Mainland.


There are several invasive plants which will never benefit from the use of biological control, and one of those is Himalayan blackberry. Any biological control agent that would effectively control this species would almost certainly damage our native rubus species, not to mention the valuable raspberries grown in the Fraser Valley


which represent a huge portion of our agriculture base. Nope, Himalayan blackberry is just going to have to be subjected to the more old-fashioned methods of weed control.


For more information on biological control agents, go to the B.C. Ministry of Forests, Lands, and Natural Resources Operations web site: http://www.for.gov.bc.ca/hra/Plants/ biocontrol/index.htm


— Jeanne Hughes is Fraser Valley Invasive Plant Council Coordinator


British Columbia Berry Grower • Fall 2011 15


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20