Got Nature? Blog

The clitellum, the set of pale, milky colored segments, is the reproductive organ of earthworms.

Purdue Landscape Report: Asian jumping worms, a group of invasive earthworms, have gained a significant amount of media attention in the last several weeks, and for good reason.  Unlike the nightcrawlers and other earthworms we know, Asian jumping worms do not improve soil health to the benefit of plants.  Instead, jumping worms (also called crazy worms, snake worms, or ‘Alabama jumpers’) almost completely strip nutrients out of soil, altering the soil structure and severely impairing the ability to develop many kinds of plants. After they are done with an area, Asian jumping worms leave behind soil that has a texture similar to that of coffee grounds and very low nutritional value. On top of this, Asian jumping worms are capable of reproducing asexually, allowing their population to grow very rapidly and making them an invasive species of some concern.

Identification
The good news is that Asian jumping worms are not well-suited to Indiana’s environment.  They aren’t capable of surviving winters in any life stage except as an egg, meaning their activity periods are limited to late June to the first hard frost of the year.  If you see worms outside of this period, it’s highly unlikely an Asian jumping worm.  There are also a few traits the worms have that you can use to visually confirm their identity.  First off, Asian jumping worms are accurately named; when handled, they writhe and thrash similar to snakes, setting them apart from common earthworms and nightcrawlers.  Jumping worms also tend to have drier skin that has an almost iridescent appearance, as compared to the slimy, moist texture of the beneficial earthworms we need for good soil health.  The most consistent feature is an organ known as the clitellum, or the reproductive organs of worms.  On common earthworms, this looks like a saddle-shape that partially covers several segments, is normally reddish-brown, and is raised off the surface of the body.  On an Asian jumping worm, however, the clitellum is indistinguishable from other segments, save for their pale, milky color.

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Resources:
The Purdue Landscape Report
Purdue Landscape Report Facebook Page
Gardeners Asked to be Vigilant This Spring for Invasive Jumping Worm, Purdue Extension – FNR Got Nature? Blog
Fall webworms: Should you manage them?, Purdue Landscape Report
Mimosa Webworm, The Education Store, Purdue Extension resource center
Sod Webworms, Turf Science at Purdue University
Bagworm caterpillars are out feeding, be ready to spray your trees, Purdue Extension Forestry & Natural Resources (FNR) Got Nature? Blog
Purdue Plant Doctor App Suite, Purdue Extension-Entomology
Landscape & Oranmentals-Bagworms, The Education Store
What are invasive species and why should I care? (How to report invasives.), Purdue Extension – FNR Got Nature? Blog
Indiana Invasive Species Council
Ask An Expert, Purdue Extension-Forestry & Natural Resources

Bob Bruner, Exotic Forest Pest Specialist
Purdue Department of Entomology