The Thousand Year Old Solution
It may come as a surprise to you that the solution to your weed problems began thousands of years ago. As plants slowly evolved in Europe and Asia, each species developed a specialized group of herbivorous insects. Some insects ate only the seeds. Others formed abnormal growths on the stems. And others devoured the insides of the root system of the plant. Through the centuries, these insects became so specialized in their diet that without their host plant, they could not survive. Today, after thousands of years of evolution, overwhelming majorities of the world's plant feeding insects are host-specific. They feed only on a single plant species or a narrow group of closely related species. It is because of this destructive feeding that these plants are an insignificant component of their native natural environment. They are uncommon, in part, because of the stress exerted upon them by these host-specific herbivorous insects.
The history of humankind is one of movement and settlement. As people expanded their travels on land and across expansive oceans, they carried with them seeds from their distant homelands. As settlers arrived in North America, some of these seeds were dumped on shore from ship ballast. Others seeds were hidden among the desirable seeds of crop plants. When these undetected and overlooked invaders became established in North America, they flourished. They were free of their evolved natural enemies; free of the insects that kept them under control. Slowly, decade after decade, these immigrant plant species spread from coast to coast. They invaded the river valleys and crept up mountainsides. Their invasion was a biological wildfire spreading from state to state. These plants are no longer the obscure wildflowers of some distant land. They are the weeds that plague millions of acres of our rangelands and pastures.
Once a weed is identified as a candidate for biological control, the US Department of Agriculture, together with foreign agricultural organizations, explores regions of the world where the weed originated. There insects are observed and the most promising candidates for biological control are collected and identified. Some are collected alive and shipped to special facilities (insect quarantine laboratories) where extensive testing is completed on the diet and reproduction of the insect under study.
Host-specificity testing is slow. Dozens of plants related to the target weed are tested. Unrelated plants, which have physical and chemical similarities, may be on the test list. Of course, crop plants, economically important to North American agriculture, are tested on the insect as well. Once the host-specificity testing is completed, a wide range of individuals examines the data. Botanists, entomologists, zoologists, agriculturists, members of the public, and the governments of Canada and Mexico all examine the host data. From that information, a determination is made whether an insect is safe for field release into the United States.
Once an insect is deemed safe for introduction, the USDA and State cooperators begin making releases of small numbers of these biological control agents. Their job is nearly done. This is where our company, Biological Control of Weeds, Inc., begins the work of developing colonies of these beneficial insects for commercial production. We develop rearing and handling techniques that ensure that our insects arrive to you, our customer, in healthy and vigorous condition. Your purchase and release of these bio-control agents is the final step in a long process and your first step to restore some balance to an unmanageable weed infestation.
North Dakota State University researchers found that the Black Dot Spurge Flea Beetle established easily along a spurge infested railroad right-of-way regardless of whether 1, 2, 3, 4 or 5 hundred beetles were released. And, by the third year of the study, "...spurge stem density decreased from an average of eighteen stems/0.25 m2 to seven stems/0.25 m2..."
-Leafy Spurge News, 10/96
Biological Control of Weeds, Inc.
1418 Maple Drive Bozeman, MT 59715