Gardeners love earthworms…but not all earthworms are good for our gardens! This month we welcomed Nicole Christensen who gave a virtual presentation about the invasive species known as the Asian Jumping Worm.
Nicole is a Certified Master Gardener who showed us how to recognize the worms, and what, if anything, can be done to combat their damage. She gave examples of worm damage to her gardens and lawn. A once flourishing Hosta garden was devastated by worm damage and an area of her lawn showed signs of worm swarming damage.
Jumping worm invasions are unique in that they consist of multiple co-invading species including Amynthas agrestis, Amynthas tokioensis, and Metaphire hilgendorphi .
It is important to be able to recognize the characteristics of a jumping worm invasion. However, the three main invaders in Connecticut are annual species, and are only easy to recognize between July and September. Instead, an invasion can be identified all year round by noting the distinctively granular soil, described as looking like ground beef or spent coffee grounds. If you are looking in summer or early fall, jumping worm presence can be confirmed by observing key features of the earthworms:
• Thrashing behavior and high densities
• Smooth, metallic sheen, often darkly pigmented, and 1.5 to 8 inches long
• Clitellum often cream colored and goes all the way around the body, unlike the lumbricid species which have a raised and pink-colored clitellum.
Jumping worms grow and mature quickly, and some species can reproduce asexually, thereby quickly reaching high densities from an initially small invading population. They grow and mature much more quickly than European or native earthworms.
What you can do to limit jumping worm invasions, because we currently lack any viable control strategies, efforts should be put on limiting human-mediated dispersal of adults and cocoons.
Best practices should include:
• Require clean equipment provisions in logging and landscaping contracts
• Heat-treat compost and mulch (130°F for three days is best but 104°F for three days should be sufficient)
• Prevent dumping of yard waste
• Plant bare-root, check for cocoons, approximately the size of a slow-release fertilizer pellet)
• Don’t move soil in tools, equipment, shoes
• Don’t dump bait or compost worms
• Don’t use compost and mulch of unknown
https://www.conngardener.com/jumping-worm-update
We learned that until this becomes an economic issue for crop production, there would be no research money or time. Perhaps that time will never come because in crop production there are strong pesticides in use and fields are turned over routinely – both of which are anathema to worms.