Jumping worms are invasive earthworms, including Amynthas agrestis, Amynthas tokioensis, and Metaphire hilgendorfi. They are known for their distinctive thrashing or snake-like movements when disturbed. These non-native species also alter soil composition, leaving behind a granular texture resembling coffee grounds. Many people are concerned about their presence, leading to questions about whether these worms pose a direct danger to humans. This article aims to clarify the risks associated with jumping worms and their broader implications.
Direct Human Interaction and Safety
Jumping worms do not pose a direct threat to human health. They do not bite or sting, nor are they venomous or known to transmit diseases to humans. Washing hands thoroughly after gardening or any activity involving soil contact is a simple and effective safety measure. This practice helps to remove any potential irritants or microorganisms present in the soil. The primary concerns associated with these worms are environmental rather than direct health hazards.
Ecological Impact and Indirect Human Concerns
Jumping worms significantly alter the structure and quality of soil. They consume large amounts of organic matter, rapidly depleting the topsoil of nutrients. This feeding activity leaves behind distinctive granular castings that resemble coffee grounds, which can make the soil dry, gravelly, and prone to erosion.
This altered soil structure negatively impacts plant growth, making it difficult for plants to establish strong root systems and absorb water and nutrients. In forest ecosystems, jumping worms can degrade the top layer of organic matter, which many native plants, insects, and animals rely on for habitat and sustenance. This degradation can reduce biodiversity and affect human activities such as gardening, landscaping, and agriculture, as plants may struggle to thrive in infested areas.
Identification and Management Strategies
Identifying jumping worms involves observing both their appearance and behavior. When disturbed, they thrash violently, often moving in a snake-like manner, and may even shed tail segments. Adult jumping worms are typically smooth, glossy, and can range from 1.5 to 8 inches in length. A key identifying feature is their milky or cream-colored clitellum, the band around their body, which completely encircles the worm and lies flat against its skin, unlike the raised, saddle-shaped clitellum of common European earthworms. The clitellum is also located closer to the head.
Management primarily focuses on preventing their spread, as there are currently no effective chemical controls. When purchasing plants, compost, or mulch, inspect them carefully for any signs of jumping worms or their distinctive coffee-ground-like soil. Opting for bare-root plants can also reduce the risk of introducing worms or their tiny, soil-like cocoons. Cleaning gardening tools, equipment, and even footwear after working in an infested area helps prevent accidental transport of worms or cocoons to new locations.
If adult worms are found, they can be hand-picked, placed in a sealed plastic bag, and left in the sun for at least 10 minutes before being disposed of in the trash. Solarization, which involves covering moistened soil with clear plastic sheeting during warm, sunny periods to heat the soil, can also help kill worms and cocoons. A mustard solution can be used to bring worms to the surface for easier collection.