For many nature lovers, one of the first experiences we had with invasive species was witnessing the spread of purple loosestrife through wetlands, marshes and ditches throughout our area over the past several decades.
Purple loosestrife became the flagship plant for invasive species awareness during the early years of the fight against it, and its deceptive beauty still taunts hikers, nature lovers and gardeners today.
With feathery plumes of beautiful pinkish-purple flowers that wave in the summer breeze, the color of the plant in bloom is simply elegant, as well as highly sought after. Fortunately, sale and transport of this highly invasive plant is now prohibited.
Purple loosestrife remains a major threat to area wetlands even though its stranglehold on our native habitats seems to have been stabilized. If we get too lax, the plant will move back in with a vengeance. That’s because just one purple loosestrife plant can produce up to 2 million tiny seeds that can be carried far and wide by the wind, water and wildlife.
Uninformed gardeners still sometimes transplant this “beautiful” plant into their own gardens, continuing the spread.
Purple loosestrife is present in all 72 counties of the state, more prevalent in areas with vast, sunny wetlands. It often grows in highway medians and roadside ditches where it can also enjoy the moist conditions where it thrives best.
An interesting but controversial attack on purple loosestrife has been implemented over the years that involves a biological control, in the form of species of special beetles, that has shown mixed results.
Researchers in the 1980s searching purple loosestrife’s native homeland in Europe for natural enemies, found insects that feed exclusively on the plant. These insects were brought here, studied and reared, and first used as a biological control against purple loosestrife in Wisconsin in 1994.
Continuous monitoring over almost two decades has shown that the insects appear to pose no threat to native plants or crops, however, the release of one exotic species to control another is often met with concern.
While the insects do not completely remove purple loosestrife from an area, they certainly do help control its spread. The beetles, which feed on all plant parts, keep the plant size in check, thereby reducing greatly the number of seeds a plant will produce. This allows native plants in the area to step up and not be overcome by the invading loosestrife.
For more information on purple loosestrife and control measures, visit http://dnr.wi.gov/topic/invasives/fact/purpleloosestrife.html
— Rob Zimmer: 920-419-3734, email@example.com