Common name: Jumping worms
Scientific name: Amynthas spp.
Hosts: Jumping worms are non-native earthworms. They are not pests of any particular plant. They damage plants indirectly by damaging the soil in which the plants are growing.
These worms, like other earthworms, change the characteristics of the soil as they process it through their bodies. The impact of this process carried out by jumping worms is a negative one, leaving the soil structure altered in such a way as to make it difficult for plants to grow properly. Soil processed by jumping worms is also more prone to erosion.
Jumping worms are an introduced species, which has spread throughout much of the eastern United States.
They pose a risk to both natural areas and home landscapes.
Damage
Jumping worms damage the soil, not plants directly.
The earthworms that have been part of American gardens since colonial times will ingest the soil, remove the nutrients they need and then excrete the remains back into the soil. The material that is excreted helps to enrich the soil and make it more friable.
Jumping worms carry out a similar process, but the end result is a negative impact on the structure of the soil.
The soil ingested by jumping worms takes on a very granulated structure, often compared to the texture of coffee grounds. This structure encourages erosion and subsequent loss of soil. In addition, the excreted soil offers little to no nutrient content for plants to use, making it difficult for plants to grow in soil infested by jumping worms.
Unlike the earthworms familiar to home gardeners, the jumping worms do not go deep into the soil. They live in the organic matter on top of the soil or in the top few inches of the soil itself.
Life Cycle
Jumping worms overwinter as eggs encased in cocoons. These are found in the soil, and are very difficult to see due to their small size and dark color.
Tiny worms will hatch from the eggs in spring, generally April and May, but exact timing is temperature dependent. The young worms will begin to feed on soil and organic matter, and will continue to do so throughout the summer, becoming mature in late summer.
When mature, the worms can be identified by certain physical characteristics. Both earthworms and jumping worms have a band that encircles their body (the clitellum). In earthworms, the clitellum is similar in color to the body, is slightly raised from the body and only partially encircles it. The clitellum of the jumping worm is light colored, contrasting with the worm’s body color, is nearly flush with the body, and encircles it completely. Jumping worms can vary in length, but can grow as long as 8 inches.
When disturbed, these worms exhibit the “jumping’ behavior that gives them their name. They don’t actually jump, but rather writhe very vigorously and move in a snake-like fashion.
At maturity, the worms will be able to reproduce, making cocoons filled with eggs. Jumping worms do not need a mate to reproduce. Each worm is able to reproduce on its own (parthenogenesis).
Adult worms will die with the occurrence of freezing weather.
Management
Cultural Management
Prevention is the best management technique.
When buying mulch or compost in bulk, check with the supplier to see if the product has been heat-treated to 130°F for three days. This will destroy cocoons.
When buying plants or obtaining plants from friends or plant sales, be wary of any plant in soil that resembles coffee grounds.
Don’t move plants from areas in the garden where you suspect the presence of jumping worms. If you have been in an area where jumping worms are known to be present, clean shoes and tools to avoid moving the cocoons or small worms.
If jumping worms are present, remove worms and seal them in a plastic bag and discard in the trash. Jumping worms cannot live long in those conditions. This will not give complete control, but reducing the adult population can ultimately reduce the number of new cocoons produced.
Chemical Management
At this time, there are no chemical pesticides labeled for management of this pest.
The pesticide information presented in this publication is current with federal and state regulations. The user is responsible for determining that the intended use is consistent with the label of the product being used. Use pesticides safely and wisely; read and follow label directions. The information given here is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement made by The Morton Arboretum.
For more information, contact The Morton Arboretum Plant Clinic at 630-719-2424 or plantclinic@mortonarb.org.