Alien Profile: Purple Loosestrife
Alias (scientific name in latin):Lythrum salicaria
Home Land (Origination): Europe & Asia
Arrival Date: 1800s brought to North America by settlers for flower gardens. Seeds were also present in ballasts of ships where soil was used to weigh down the vessels for stability on the ocean.
How to Identify:
Disguise (don't be fooled by look-alikes): Looks like swamp loosestrife, fireweed, blue vervain, winged loosestrife, blazing star, and gayfeather, but these are harmless. Look at a field guide to tell them apart.
(Look out for alien helpers): Watch it! Some garden centers and seed mixes have purple loosestrife in them, check the label for this sneaky alien. Garden varieties of loosestrife have also been proven to pollinate with purple loosestrife and help it multiply. You can help, don't plant garden varietites of these alien helpers.
Evidence: Purple stalks blooming in wetlands from June through early August. When purple loosestrife gets a foothold, the habitat where fish and wildlife feed, seek shelter, reproduce and rear young, quickly becomes choked under a sea of purple flowers. Some wildlife will eventually leave to find better habitat but the native plants and insects that can't move are killed by this invasion. An estimated 40,000 acres of wetlands, marshes, pastures and wet meadows in Wisconsin are affected, with an economic impact of millions of dollars.
Invaded Territory: All across Canada and the United States
Extermination Techniques: Traditional control methods, such as cutting, pulling, flooding and treating with herbicides can be time consuming. Nature itself can help! Biological controls (other plants or animals that feed on the plant) can help as long as they don't become "pests" themselves. A good solution is an insect that only craves eating the purple loosestrife. Several species of insects have been studied by the Wisconsin Department of Natural Resources at controlled release sites. The Galerucella beetles will eat the leaves quickly and can keep the plant from flowering. Unfortunately Galerucella doesn't spread to new sites quickly, but people have been starting new colonies and moving them to infested areas. Some citizen groups have already jumped in and helped raise the beetles in a nursery, released and monitored them on the landscape. This is a great community or class project. DNR researchers can supply you with directions and the technical know-how to raise and release the beeetles. Call 608-266-2554 or send an email to Brock Woods, Research Ecologist at the DNR at Brock.Woods@wisconsin.gov.
Help Stop the Alien Invasion!You can help teach people about these invaders, contact: nurseries that grow flowering plants, community garden groups, conservation groups, the agricultural community, and your next door neighbor. The best time to control purple loosestrife is June through August when it's in flower and before it goes to seed. Purple loosestrife can be controlled by these methods: