Hammerhead Henry(etta) versus Jumping Jo(sephine)
Are hermaphroditic worms squaring off in your garden?
February garden
During a spell of unseasonably warm weather in February, I worked as much as I could to prepare the garden for spring. I happened to turn over a rock and discovered the worm shown in the photograph below. According to iNaturalist, this slimy yellow fellow is a planarian, probably Bipalium adventitum, or wandering hammerhead worm.
Wandering hammerhead worm
You might recall planarians from middle school science class where they are often used for student experiments due to their ability to regenerate from severed body parts. Species used for this purpose are usually freshwater planaria, whereas my garden buddy is a terrestrial flatworm. It too is probably able to undergo binary fission, meaning it can split into two parts, each of which will regrow the missing part. It's believed, however, that this particular worm usually reproduces sexually.
These hermaphroditic hammerhead worms, or landchovies as they are sometimes called, were discovered in the U.S. as early as the 1940s, and were probably brought in with plant material from Asia. They didn't receive much attention until the last few years, when news stories about them began to proliferate. Their creepy appearance and their ability to produce tetrodotoxin, the neurotoxin found in pufferfish and the blue-ringed octopus, makes for great copy. Also, populations seem to be expanding with warmer and wetter conditions, and more gardeners are encountering them.
Dormant flower bed harboring who knows what creepy crawlies
There are no doubt countless disgust-inspiring creatures in soil and mulch of healthy gardens, but most are too small to catch the casual eye, leaving us blissfully unaware. Planaria are easily viewed and, to be honest, look evil and out of place. A gardener could be forgiven if her first instinct was a killing spree to attempt to eradicate them, especially when encountering something like this:
Bipalium kewense, photo courtesy of Wikipedia
That's not my modus operandi, and I sought positive identification and more information before taking action. Though these worms produce a neurotoxin, there's little evidence that humans are at risk. It's advised to wear gloves when handling them and to refrain from eating them — in other words, just use common sense.
The most auspicious aspect of the presence of these worms is that their main foods are earthworms and slugs. Slugs are the bane of most gardeners, and though earthworms have traditionally been a welcome sight in soil, they are increasingly controversial. Native earthworms disappeared from much of the northeast U.S. during the last period of glaciation, and have been largely replaced by worms carried here by European settlers. Now these worms are in turn being usurped by Asian jumping worms. Both of these hermaphroditic foreigners process organic matter more quickly than than would occur in their absence, prompting fears of negative changes to forest ecosystems.
Peach buds
Boreal forests, stretching across much of Canada and Alaska, are believed to be particularly at risk. In these northern forests dominated by conifers, a thick layer of duff covers the ground and represents a large portion of the biomass. Earthworms consume this layer and speed up the cycle of decay, potentially resulting in ecosystem disruption, and northern forests becoming carbon emitters.
Far south of boreal regions in southern Ohio, the effect of non-native earthworms on our forests remains to be seen. I'm used to losing organic matter quickly in the garden due to our long, usually very wet, summers, so the thought isn't bothersome. European earthworms probably had a net positive effect in the garden. The jumping worms that have supplanted them tend to turn the top soil layer into hydrophobic granules, but my habit of building up soil constantly with mulch and compost means I haven't had observable detrimental effects.
Now enters the newest invader, the slug-slayer and worm-waster Bipalium adventitum. Will it slither in like a glistening knight-errant to purge the garden-kingdom of the pestilence of slugs and jumping worms, then fade away when the job is done? Or will it find its niche and eke out a living by snagging the occasional gastropod without significantly reducing populations? I cannot know for sure, so I will proceed by doing nothing.
Humble Hellebores
The internet is overflowing with advice to smash spotted lanternflies, crush the egg cases of Chinese mantids, gently dispatch brown marmorated stick bugs, and in general annihilate invading invertebrates. I ignore this advice — I'm inured to instructions to kill, kill, kill, and have no trouble resisting. After observing the same scenario play out many times without the world ending, I believe the onslaught is inevitable and efforts to avoid it are mostly wasted time. Better to put energy into strengthening ecosystems in general by increasing biomass, retaining water longer, and removing what is observed firsthand to be detrimental.
Quotes from an over-the-top article on killing invasive bugs
I'm especially reluctant to kill invaders if there is a chance they will kill each other. Though it will take place far from human sight in moist leaves and under rock and mulch, an epic battle between hermaphroditic worms is possible. As I imagine it, an army of landchovies will follow chemical trails to locate prey, which they will ensnare and coat with toxic slime. They will then suck out the insides of their victims, and poop the waste out their mouths.
View from the garden
The only part of this scenario that is fantasy is the scale — perhaps there will be no legion of Bipalium. However, individual planaria track and consume prey as described above, and while I probably won't ever observe it, I'll be on the lookout for telltale changes in the garden. I'll keep readers updated as the drama unfolds.
We are constantly being lied to about the environment...just like everything else. In my own state of Oregon...it is practically shoved in our faces. Two days ago a wolverine was filmed 24 miles from my home. One was in the area a year ago, and another last year crossed a highway about 100 miles south of me. Four years ago one was filmed dining on a dead seal on the beach just across the Columbia river. Wolverines are supposed to be "forced north, searching for heavy snow areas, that are disappearing". No. They are recolonizing Oregon, just as wolves have done, over the last 20 years. Next will be grizzlies, as there have been sightings in NE Oregon. Last summer a cougar was strolling on a highly populated tourist beach. While massive numbers of new people have moved here ... the only thing that brought all this wildlife back...was to simply stop the hunting and trapping.
Florida is an example. When I moved to the Keys in 1980, the American crocodile was so threatened, it existed in a tiny corner of Everglades National Park. To my chagrin, one could only view them with a ranger...IF you had a darn good reason. I asked a ranger about panthers. To quote him: "There might be one Florida panther in all of south Florida". Fast forward 44 years. There are now 13 million more people living in Florida (and that's a low estimate). Florida panthers are now so common, they show up on door cams eating the family dog. American crocodiles have made a miraculous comeback. They are turning up in back yards all the way north to Tampa. When Key Largo recently flooded, the crocs were swimming in the flooded streets, making people afraid to wade to the store.
I'm sick to death being lied to, by the global elite. About wildlife, and all the other lies. According to them, human over-population and habitat loss is killing all the wildlife. Don't believe your lyin' eyes when you see a wolverine, cougar or crocodile on your doorstep... believe what we tell you. I'm sorry ...but I don't believe the bs anymore. I have critical thinking skills, and I've lived almost 64 years, and I REMEMBER how rare it was to see this kind of wildlife as a child. Seeing a Canada goose was a rare sight in 1966. Now their poop covers the ground in every park. I'm not complaining. I love to see the RETURN of almost-hunted-to-extinction animals. However, gardeners would do well to use their own experience to make choices about their land. Leave the environmental propaganda for the idiots who believe msm.
Yucky and interesting too. Where in US are you Lynn? I’m in PNW. 💞