Native weeds are bad enough. Invasive weeds are worse, and invasive hybrid weeds are things of nightmares. As if single invasive species of plants weren’t powerful enough on their own, a recent article from Michigan Farm News makes us aware of the fact that we may need to worry about invasive hybrids.
According to the article, hybrid invasive weeds are two species that breed to create a particularly powerful force that can be even more improbable to get rid of. The article cites a study published in the Invasive Plant Science and Management Journal that focuses specifically on Japanese knotweed and giant knotweed, two invasives prevalent throughout the Great Lakes region. According to Michigan Farm News, studies have been performed looking at the two species in Europe and Asia, but not in North America.
The article focuses on the hybrid and spreading potential of these two species with each other. Japanese knotweed has been found to produce small seeds that are shown to be hybrids with the giant knotweed. The authors of the article warn of the particular vigor and fertility of hybrids, such as these. A process known as introgression, where a hybrid crosses again with one of its parents was also shown in the study. The process has been known to produce a greater diversity in invasives.
Both types of knotweed originate in Asia, particularly in Japan, and are now prevalent throughout the Great Lakes region. Japanese knotweed has been found in Michigan, Minnesota and Wisconsin, and giant knotweed is in Michigan and Wisconsin.
In 2009, the British government believed that they had found a way to stop the spread of Japanese knotweed through the use of an insect known as the aphalara itadori. The bug is thought to biologically control the weed by drinking its sap. I wonder if the same method of control could tame the hybrids that may be the next source of destruction to the Great Lakes ecosystem.