Recommended resources and links to learn more about invasive Amynthas (jumping worm) species. All links open in new tabs.

Good article about what jumping worms are doing to American forests: https://www.theatlantic.com/science/archive/2020/01/jumping-worms-are-taking-over-north-american-forests/605257/

A good, but long, video from the University of Wisconsin (Madison) Arboretum, origin of one of the major studies on jumping worms. https://youtu.be/8CPQH8q1Pfc The thrashing behaviour is shown at 19:24 in the video.

A brief summary of jumping worm information (source: Master Gardeners of Ontario Facebook Group)

General

  • ALL earthworms are NON NATIVE to Ontario and can have negative effects on soil health.
  • JWs are especially problematic and have a very negative effect on soil health by changing the chemical, physical profile of the soil as well as biological changes, e.g. to nesting birds, invertebrates. Their castings cause soil to dry out and become highly erodible.
  • JWs are common in grass/turf habitats and live in the very top layer of soil.·
  • Report all sightings of JWs to EDDMappS at https://www.eddmaps.org/.

Jumping Worm ID

  • JWs start to hatch each year when the temperatures reach 10C/50F. Any large worms you see in the spring would not be JWs. Look for them in late summer-July, August into the fall.
  • JWs have a 2-tone colour-darker on their dorsal (back) than on their ventral side.
  • Size varies on species from 3 inches (A. tokioensis), 5 inches (A. agrestis), 8 -12 inches Metaphire hilgendorphi (10:34 in video)
  • JWs have a more “rigid” body, as opposed to earthworms which are more “flaccid” and can wrap around your finger.
  • Adult JWs have a SMOOTH, white, milky “clitellum” nearer their head. If you rub your finger over it, you can’t tell it’s there. It also goes all the way around the body. No other earthworm has this. Other earthworms will have a “raised” clitellum you can “feel” and that does not wrap around completely on the underside.
  • Behaviour: JWs are very active, and have a rigid body and tiny hairs that completely encircle each segment, allowing it to “bounce” and actually jump into the air. Other earthworms “wiggle”. The thrashing behaviour can be extreme and prolonged
  • Soil: JW excrement (castings) are dry, large, loose, and granular. Some say they look like coffee grounds; others compare them to taco meat. Other earthworms make “piles” of castings.
  • JWs can drop their tail when they are aggravated (a function of the ‘rigid’ body type.) Other earthworms don’t do that.
  • JWs have an annual life cycle. They die off in winter and grow from cocoons in spring. It takes about 70 days (some sources say 60 days) to grow to an identifiable size. Juvenile JWs are tiny, about 10 mm in length.
  • Large worms seen early in the year are not likely JWs. Small white worms seen in spring are “pot worms”, not JWs and not actually an earthworm at all.
  • JW cocoons are almost impossible to differentiate from soil particles.

Negative Impacts of JWs

  • Their castings cause soil to dry out and become very prone to erosion. When it rains, soil can wash away.
  • Perennials need nutrients in the spring. JW populations are highest in the fall and producing a lot of nutrients. The nutrients get washed away and leave nothing for plants in the spring.
  • JWs can destroy turf grass and eat plant roots, especially of turf grass.

How They Are Spreading

  • Mainly organic materials such as compost, mulch, leaves.
  • Plant sales (especially garden clubs) and plant sharing
  • Shoes/boots, tires
  • Landscaping companies, fishing/bait industry
  • Found in all habitats, e.g. lawns, gardens, forests, except for prairies (so far).

Potential Controls Being Explored (47:07 in video)

  • Saponins: “Early Bird” fertilizer, used in the golf course industry to kill earthworms, has a by product of the ‘tea seed tree’ as an ingredient, which is high in saponins (a defense for plants against herbivory). It is very expensive to buy and may be hard to find because of tariffs (from China). There is a concern re: potential negative impacts of saponins on other soil biota such as springtails. Saponins should be used on a small scale only. Alfafa is another source of saponins.
  • Biochar (soil amendment) may reduce numbers of JWs due to the sharp granular composition. Mix into the soil as JWs may be able to move away from it if left on the surface.
  • Heat: 40C for 4-5 hours MAY kill cocoons and earthworms (video ~52:05). Lab research indicates 3 days at 40C will definitely kill all cocoons but one of the researchers suspects that the “kill time” is a lot less than 3 days.
  • A prescribed fire will reduce cocoons, but adults may go deeper in the soil. Prescribed fires are only for professionals–do not try this at home! o
  • Solarisation using clear plastic in spring with sun will kill cocoons. Propane torches may be used for sterilizing soil in yards. Again, take precautions when using fire!
  • Reduce the amount of mulch or use grass, hay or pine needle mulch.
  • Purchase all products (soil, compost, mulch) from reputable sources. Ask providers if their products are JW free. If they have no idea, be concerned.

How to Stop the Spread

  • Educate yourself and understand what JWs look like including castings and how soil is affected.
  • Ask nurseries if they’ve had JW issues. Again, if they have no idea, then be concerned.
  • Examine new plants. Is the plant healthy? Is the soil intact or granular?
  • Arrive in a garden clean (tools, shoes, tires) and leave clean removing all soil, debris etc.
  • While compost that was properly heated up should not have worms of cocoons, processing could be introduced via backhoes etc.
  • Produce your own compost or leaf mulch.

How to Check for JWs

  • Is the soil granular? Or is it intact?
  • Test Your Soil Mix a 1/3 cup ground mustard to a gallon of water. Remove any leaf layer/mulch and pour ½ solution on soil. All earthworms will react but look for the white clitellum of the JW and remove as they appear. (44:10 on video)
  • Update for reporting JWs: The Canadian Food Inspection Agency office (CFIA) is no longer requesting they be alerted as the worms are confirmed. They suggest that “Property owners should contact a pest control company to inquire about control methods that may be effective in reducing populations.” Keep in mind that even pest control companies will have few ways to combat JWs. JWs are a threat to our natural lands, forests, gardens, plants, & biodiversity. Please contact local governments and agencies to make your concerns known.