See a worm in your yard? It might be invasive |
See a worm in your yard? It might be invasive
(NEXSTAR) – Earthworms aren’t necessarily a surprising sight after a day of rain or while working in a garden. Despite their apparent value, those wriggly wigglers are most likely invasive.
Whether or not the worm you’re seeing is invasive will depend on where you live and, of course, the species of worm.
“Places that got glaciated 10,000 years ago, there are very few native earthworms, if any, in those areas,” Michael Skvarla, an assistant research professor and head of the Insect Identification Laboratory at Penn State University, told Nexstar.
Thousands of years ago, all or part of many northern states – Montana, North Dakota, South Dakota, Nebraska, Kansas, Minnesota, Iowa, Missouri, Wisconsin, Illinois, Indiana, Michigan, Ohio, Kentucky, Pennsylvania, New York, Vermont, New Hampshire, Maine, Massachusetts, Connecticut, Rhode Island, and New Jersey – were covered by glaciers.
Those glaciers are said to have mostly killed the native earthworms in these regions. Meanwhile, unglaciated areas can boast dozens of native worm species.
Some native earthworms can be found in parts of New York and Pennsylvania, Skvarla said. In Minnesota, however, officials say all of the terrestrial earthworms “are non-native, invasive species from Europe and Asia.” At least seven of the species found in there are contributing to tree seedling, wildflower, and fern loss in the state’s hardwood forests, the Department of Natural Resources reports.
If you live in these once glaciated areas, the earthworms you’re encountering are more likely to be from Europe, Skvarla said. Early immigrants had to use rocks and dirt as ballast........