Jumping Worms

Media
Jumping worm lying on soil, with a person's fingers for scale
Status
Name
Invasive
Scientific Name
Amynthas and Metaphire spp.
Family
Megascolecidae (a family of earthworms) in phylum Annelida (segmented worms)
Description

Jumping worms, also called Alabama jumpers, snake worms, or other names, are invasive earthworms that are native to east Asia. They are now spreading in North America, including Missouri. The common names arose from the way they violently thrash around when disturbed.

At least three species of these nonnative jumping worms have begun to spread invasively in North America: Amynthas agrestis, Amynthas tokioensis, and Metaphire hilgendorfi.

Key Identifiers:

  • Lighter on bottom surface; darker on top
  • Skin is grayish or brownish, glossy, sometimes iridescent
  • Clitellum (collarlike band about a quarter of the distance behind the head) is creamy white and is smooth (not raised or swollen looking); it completely encircles the body
  • Generally slender, dry, smooth, and firm (not slimy and thick like our more familiar earthworms)
  • Thrashes wildly when disturbed; has snakelike movements; sometimes sheds tail in defense
  • Established populations make the soil resemble coffee grounds

Similar species: Our more common species of earthworms (Lumbricus spp.), including nightcrawlers, are pink or salmon-colored and are slimy. The collarlike clitellum is swollen (raised higher than the rest of the worm) and only partially encircles the body. Their usual movements are slower than those of the invasive jumping worms. They do not make the soil look like coffee grounds or cooked ground beef.

To learn more about earthworms in general, see their group page.

Common Name Synonyms
Alabama Jumpers
Snake Worms
Size

Adult length: 4–8 inches.

Where To Find

Potentially statewide.

Usually found in the top 3 or 4 inches of soil. These worms are largest, most conspicuous, and most abundant from midsummer until freezing weather. Where they are most numerous, the soil begins to resemble coffee grounds or cooked ground beef.

Like other invasive species, they disrupt natural ecosystems. Jumping worms damage plant roots, deplete organic nutrients in soils, alter the water-holding capacity of the soil, change the soil structure, and outgrow and outcompete other earthworms. Plants with damaged roots are more likely to succumb to other hardships, such as drought, pests, and diseases.

These earthworms eat nearly any organic matter. Different species of earthworms specialize in eating at different layers of the soil. These spend a lot of time at the top few inches of soil, and they eat up nearly all the surface leaf litter and just about any other organic material.

Invasive.

Life Cycle

Jumping worms grow and reproduce more rapidly than our other earthworms. A single worm can create viable eggs without having a mate, so only one worm can create an entire population. It only takes 60 days from the time an egg hatches to it becoming a sexually mature adult; that means there can easily be two broods a year, and exponential growth. The egg cases (called capsules or cocoons) are tiny, about the size of a pinhead. Newly hatched young are difficult to see because they, too, are tiny. They go unnoticed until they are large enough to already be producing more egg capsules.

Adult jumping worms may not survive our winters, but their eggs can. The egg cases are small enough to be transported accidentally from one location to another — in the soil of a potted plant, in compost, in dirt clinging to a backhoe, or even in some mud stuck to your boot. This is why it’s important to take measures not to accidentally spread these worms from infested areas into places free from them.

Jumping worms were originally introduced to our continent for use in composting and to be sold as fishing bait. Their jerky movements made them attractive to fish and therefore to anglers. Their stupendous ability to eat up plant matter made them (at first) seem like a good idea for worm composting. In fact, however, their ultimate effect is to reduce nutrients in soils.

They can damage lawns and landscaping.

There’s no good way to control nonnative earthworms once they’ve been established. To prevent or slow the spread of invasive jumping worms,

  • Do not buy them, whether for bait, for composting, or for gardening. Never dump live bait into natural habitats.
  • Avoid transporting them: clean any digging equipment (such as washing tires of construction equipment) before moving to another site; reduce transportation of soil or mulch; carefully inspect nursery plants before planting them in a new site.
  • If you find them, whether in your soil or in potting soil from a garden center, put the worms into a plastic bag, leave it in the sun for 10 minutes or more, then put the bag in the trash. Alternatively, soak the worms in isopropyl (rubbing) alcohol. Do not put the dead worms in your garden or compost pile.
  • If you purchase compost or other organic material for soil amendment, make sure it has been heated to reduce the spread of insects, weeds, and plant pathogens. The eggs of jumping worms cannot survive temperatures more than 104 F.
  • Removal of adult jumping worms can dramatically decrease the number of egg cases they create.

If you are interested in a career in the sciences, earthworm biology and soil ecology is an understudied, but incredibly important field. Healthy soils are critical for nature, agriculture, and ultimately human survival.

Invasive jumping worms consume more soil nutrients than other earthworms, meaning that they actually deplete the soil of nutrients, rendering the soil less fertile for plants; and without plants, the soil is more likely to erode. Where a large population of these worms is established, the soil surface looks dry and granular, like coffee grounds or cooked up ground beef. Leaf litter disappears.

Invasive jumping worms damage forest ecosystems by rapidly eating up the leaf litter that usually protects forest topsoils. Without that mulchlike layer, the bare soil dries rapidly and is subject to erosion. Young forest plants have a difficult time getting established. The soil chemistry changes, and the soil’s microbial communities (bacterial, fungi, and other microbes) change as well. The amount of mycorrhizal fungi (which attach to plant roots in a symbiotic relationship) declines, making it harder for trees to take in nutrients.

Without the protective layer of leaf litter, many invertebrates (other worms, millipedes, centipedes, springtails, arachnids, and countless types of insects), plus amphibians, reptiles, small mammals, and ground-nesting birds, lose important habitat. Thus species diversity declines and forest food chains are disrupted.

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About Land Invertebrates in Missouri
Invertebrates are animals without backbones, including earthworms, slugs, snails, and arthropods. Arthropods—invertebrates with “jointed legs” — are a group of invertebrates that includes crayfish, shrimp, millipedes, centipedes, mites, spiders, and insects. There may be as many as 10 million species of insects alive on earth today, and they probably constitute more than 90 percent all animal species.