I spent a couple hours over the weekend looking at the worms in my garden to figure out if they are invasive Asian jumping worms (JWs). If you haven’t heard of JWs, please check out the links below and become familiar with them and learn how to identify them.
Here’s a link to an article from the UMass Amherst AG/landscape website:
I was worried when I found a large number of worms in one area, so I collected some to try to ID them. The most distinguishing trait of the JW is that they are very energetic and literally jump when you touch them. There are many videos online – be warned, they’re disgusting!! I finally found one document (link below) that gave me something specific to look for – the setae, or tiny bristle-like structures that worms use to move. In JWs, each segment has a ring of >40 setae while common earthworms have 2 evenly spaced pairs and nightcrawlers have 8 evenly spaced setae.
I have a small USB microscope and set it up to take a look. Here’s what I saw. The worm itself is pinkish, not black as in the photo (that’s an artifact of the USB camera).
A few other features that are helpful are:
- The clitellum (light colored ring) on the JW is closer to the mouth, usually less than 10 segments away. In other worms, it’s about 20 segments away.
- The clitellum is milky in JWs, is flush with the body and fully encircles the worm. In other worms, the clitellum is raised and does not fully wrap around the worm; rather it is saddle shaped. (I’ll admit, this one is difficult for me to see).
- JWs only live one season. They hatch from eggs that mature in a cocoon-like structure and they die each winter. My understanding from what I read is that right now in New England (April), most JWs will still be small. Mature JWs shouldn’t be abundant until later in the summer.
- JWs have darker pigment compared to other worms that are pinkish colored.