A couple of weeks ago I wrote about the Joro spider that is working its way up the east coast of the U.S., and could arrive in Maine within the next 10 years.
Well, hang on to your hats, because here we go again with a native Asian invader to the state of Maine. The hammerhead worm — a toxic, predatory invasive worm capable of unlimited self-cloning — has arrived in Maine.
The first sightings were reported last fall from southern and central parts of Maine of the hammerhead worm, a flatworm that can range from 8- to 15-inches long and is distinguished by the unique hammer or shovel-shaped head.
“We have a couple of reports of them already,” said Gary Fish, state horticulturist with the Maine Department of Agriculture, Conservation and Forestry. “I don’t think anyone in Maine is up to speed on them,” he said in a news article published in the Bangor Daily News by Liz Baker.
The discovery is bad news for Maine’s gardeners since hammerheads prey on earthworms, which contribute to the health of Maine soil by turning organic materials into useful compost. Earthworm activity also helps aerate the soil, which increases soil nutrients and moisture intake.
The hammerhead worm can prove additionally troublesome because it has no known predators.
The hammerhead worm is native to Asia and has been reported as far south as Florida, as far west as California and now as far north as Maine, according to the University of Florida.
The biology of the hammerhead reads like a horror movie. It does not have respiratory or circulatory systems or a skeleton, and it may or may not have eyes. What it does have is a single opening on its head that serves as both its mouth and its anus. (Sounds like something that is tailor made for an episode of Svengoolie.)
Baker spotted one slithering up her foundation in Lewiston last fall.
In the BDN article, Baker said, “I was fascinated. Totally creepy and strange but I love learning about different species [and] I had never seen anything like it.”
The truly amazing trait of hammerhead worms is that they are basically immortal. Like other flatworms, they reproduce asexually by what is known as “fragmentation.” For example, they leave the tip of their tail stuck to something, and it will develop on its own into a new worm.
That also means if you cut a hammerhead into pieces, in 10 days or so you are going to have multiple new hammerheads — all capable of fragmentation.
They are also the first land invertebrates found to produce the same toxin that is found in pufferfish. In the fish, the toxin is lethal to humans with one pufferfish containing enough to kill 30 adult humans. Little is known about the hammerhead toxin’s effects on humans, but it is believed a person would have to eat a large quantity of them to be lethal. Yuck! Are you kidding me? Who’d want to eat a worm? However, it is a good idea to wash your hands after handling hammerhead worms.
So, what do you do if you spot hammerhead worms, and don’t want to see an entire colony form in your yard?
Because hammerhead worms consume beneficial worms, secrete poisonous toxins, and transmit harmful nematode parasites, they should be removed and dispatched whenever found.
If you spot a hammerhead worm, take a photo. Should you kill hammerhead worms? Yes, but first take a photo and send it to your local cooperative extension service, your state’s department of natural resources. These groups study and track invasive species like this worm, gathering numbers and locations of sightings.
Collect hammerhead worms in a sealable container. If you find a hammerhead worm in your garden, capture it in a sealable plastic bag or some other sealable container. Don’t touch it with your hands; use a stick, gloves, or paper towel to place it into the container. If you do touch it, be sure to wash and disinfect your hands. Placing the worms in a container ensures they won’t be able to get away and makes it easier to apply a solution to kill them.
Apply salt and/or grain vinegar concentrate to the hammerhead worms in the bag, seal the bag, and place it in the freezer for 48 hours to ensure the worm has dissolved. Soapy water, neem oil, citrus oil, boric acid, or pesticides may also work.
Do not cut the worm into pieces. Each section can regenerate into a fully developed worm within a few weeks.
Discard the dissolved worms and sanitize the container.
After a hammerhead worm has been sealed in a plastic bag, treated with salt (or a combination of salt and vinegar), and placed in the freezer for 48 hours, the Texas Invasive Species Institute recommends discarding the still-sealed baggie in the trash.
Alternatively, you can use a glass jar with a lid or any kind of plastic sealable container. Most sources advise tossing the sealed container into the trash, but if you prefer to reuse it, it should be cleaned and disinfected with alcohol or another strong disinfectant.
If you have found one hammerhead worm, there are probably more, so remain vigilant. Examine your garden, particularly in the early morning after a rain when they’re likely to be easily found on the surface.
It’s important to keep an eye out for these invasive, toxic worms. The slimy predators threaten earthworms, which are vital to our ecosystem because they help decompose organic matter and incorporate soil amendments. Knowing how to identify and correctly kill and dispose of these nuisance worms will help keep your garden and your pets safe and healthy.
Roland’s trivia question of the week:
Who holds the Boston Red Sox team record for most hits in a single season?
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