Flatworms could be a really serious pest and without doubt Britain’s gardeners are to blame.” Manchester University’s Hugh Jones is blunt as he describes the arrival and spread of the latest menace to threaten our flora.

He is referring to the alien worm which is destroying our native earthworm population. The dark-brown invader was first discovered some 30 years ago in Belfast gardens and identified in London’s Natural History Museum as Artioposthia triangulata, a native of New Zealand’s South Island beech forests. This small, ribbon-like creature almost certainly travelled half way around the globe as a stowaway in the soil of pot plants.

When motionless the flatworm is just 2-3in long, but this changes to 6-8in as it moves along – and it is capable of squeezing through the thinnest gap (one report details an escape through the knot of a tied up polythene bag). It feeds by enveloping a hapless earthworm with its body and secreting copious amounts of slime laden with digestive enzymes. This reduces the unfortunate victim to a soup which the predator then drinks through a mouth in its underside.

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This has worrying implications for farmers and gardeners alike. Earthworms are an essential part of fertility in many areas, particularly in wet or thin soil unsuitable for ploughing. “Earthworms are vital to drainage – particularly the top 6-9in of soil,” says Dr Jones. “Without them many naturally damp pastures would revert to marshland.”

In addition, earthworms drag nutrients down from the surface and aerate the soil. Many plants use their tunnels as an easy way of extending their root systems. As a result, there is a clear correlation between worm numbers and plant growth.

Flatworms upset this delicate balance as they literally drink their way through our native species. Researchers in Northern Ireland have discovered that under ideal conditions, a flatworm eats 14 worms a week but if the supply dries up, rather than starving or moving to pastures new, it will simply stop eating. Apparently flatworms can survive for a year without food by reducing their reproduction and slowly absorbing their own tissue.

One of the major problems tackling the menace is that very little is known about the flatworm – both here and in its native environment. Hugh Jones, for example says the new species are being discovered almost weekly in its native habitat and as a result he is uncertain of the identity of a second British invader. “We think it is Caenoplana alba, but we are waiting until Australian taxonomists finish detailing their native species before we can be sure,” he says. For the time being, he and his fellow researchers refer to it as the “pink un”.

Unlike its New Zealand cousin, the second species has spread north from an origin in southern Britain. Fortunately, being rather smaller, it appears less harmful to biggest native worms. But it is a worry nevertheless.

Derek Cosens, a senior lecturer at Edinburgh University, says this is typical of virtually every aspect of our knowledge. Although one of Britain’s leading flatworm experts, he admits that his research is based mainly on project work done by his final year undergraduates. Dr Cosens believes the worms depend on cold, wet and damp conditions and are thus likely remain confined to the west and north of Britain.

The flatworm seems to have almost no predators but some preliminary research in Edinburgh now suggests a so-far unidentified beetle may eat the invader. “What we really need is funding for a post-gradutate to do a thesis,” says Dr Cosens. “That would revolutionise our understanding.”

In the meantime, what do you do if you find your garden has been invaded by flatworms? Dr Jones at Manchester University says that to kill a flatworm you sprinkle salt on it or drop in jam jar of water or vinegar. And if you want to help find a remedy to flatworms you could start by sending him your samples. Put them in a small sealed pot with a bit of damp tissue and address your package to Dr Hugh Jones, 3239 Stopford Buildings, University of Manchester, Manchester M13 9PT.

New Zealand and Australian Flatworm


The New Zealand flatworm (Arthurdendyus triangulatus) was first noted in the western parts of Scotland in the early 1960s. Flatworms have now been identified throughout Scotland.

In its native New Zealand, the flatworm is found in shady, wooded areas and only on the cooler South Island. Flatworms were probably introduced into the UK in the soil in pot plants sent or brought from New Zealand.
The flatworm has taken hold in a lot of gardens and garden centres without people realising it. After they have decimated the earthworms and therefore their food source, flatworms shrink to a tiny size and lay dormant, so eventually people might notice that they don’t have a lot of earthworms, but don’t know why.


When resting, flatworms will be coiled and covered in mucus. They are very distinctive and look nothing like earthworms. The upper surface is dark, purplish brown with a narrow, pale buff edge.

The underside is also pale buff. They are pointed at both ends, and ribbon-flat. A mature flatworm at rest is about 1cm wide and 6cm long. When extended, it can be up to 30cm long, and proportionally narrower. Flatworm ‘eggs’ or capsules are shiny black, just under 1cm long, and like a misshapen blackcurrant. They contain as few as two, or as many as eleven young worms.

The worms seem to be simple ancient life forms that have survived for tens of thousands of years in a little pocket on a small island. They have no internal organs: digestion is done outside the body and interned by osmosis through the skin.

Australian flatworm

Several other species of flatworm have been found in the UK since the introduction of A. triangulata. They are the same shape as the common form, but come in different colours, the orangey-red Australian Flatworm (Australoplana sanguinea var alba) which is common in England, or the creamy white Edinburgh Flatworm (Arthurdendyus albidus) only known from Edinburgh.

WARNING: Some people find flatworm mucus irritant, so wear gloves if handling them.

Life Cycle

New Zealand flatworm life cycle

Adult flatworms produce egg capsules in summer. A capsule can be between 4-11mm long and 3-8mm wide, and resemble a blackcurrant. Juvenile flatworms emerge after about a month and are creamy white/pink in colour.

Feeding Habits

Flatworms seem to eat earthworms exclusively. There is no evidence that they will eat any other soil-dwelling creatures, even when the earthworm population has been reduced to below detectable levels. There is no apparent preference for one particular worm species. Flatworms are most active near the soil surface, so deeper burrowing earthworms are more likely to survive despite the presence of flatworms.

When an earthworm is located, the flatworm covers it with digestive juices. This dissolves the earthworm, which is then sucked up by the predator. Estimates suggest that flatworms will consume one or two earthworms per week. When its food supply has been virtually exhausted, a flatworm will shrink and wait until there are sufficient earthworms for feeding to restart. This waiting time can be as long as 12-24 months. It is not yet clear whether flatworms will move long distances to alternative feeding sites.

What’s the Cure?

There is none! Once it is in your garden, it is there to stay.

Prevention is the Only Method of Control

Seeds, cuttings and clean bare-rooted plants are safe. Soil and manure needs to be inspected really carefully. Best NOT to buy plants in soil from nurseries and do NOT accept soil in any shape from well-meaning friends. One egg the size of a black current is enough to infect your garden.
The best way to get new plants in your garden is to import them with seed or cuttings. Or at least bare rooted. That also helps prevent importing other pests and diseases. This is becoming more and more important.

An infected garden is bad, but not the end of the world.

It is possible to live with the flatworm and help the earth worm population recover by continuously capturing the flatworms and setting up an earthworm farm on stilts. Flatworms like to rest underneath plastic bags that keep the soil moist.

Photo by Jessica Kate Watts in her garden in Co Mayo, not far from Croagh Patrick. Click on the image to see full size picture

Best way to kill them is to use a jam jar with salt to contain and kill them. Ground beetles seem to attack smaller worms. Providing a safe habitat for those beetles help a little. (see Dealing with Slugs in a Permaculture Garden) Mulching and adding lots of organic matter to your garden is something you do in a permaculture garden anyway, but it helps to keep the soil healthy with less earthworms doing the digging for you.

Several natural enemies are known from New Zealand. However, little is known about their biology and they are unlikely to be specific to the one species of flatworm. As a result, it could be difficult to find good biological control agents that attack only the target flatworms.

There is some anecdotal reports from people that the earth worms and flatworms eventually coexist in some sort of balance.

Dangerous Myths:

  • Immersing them in warm water (+34°C) for ten minutes might kill the worms, but not the eggs.
  • Immersing the soil of plants in water for 24 hours will bring the mature worms to the surface, but again, not the eggs.
  • Plants from nurseries are safe.

Pictures and info: CC licence

How to handle flatworms

Q I have found hammerhead worms in my flower beds. Is there something to spray on the beds to kill them, or do I have to wait till I see them on the patio?

G.T., Spring

Answer: The flatworm, or land planarian, is a nasty little beast that can be devastating to earthworms and other beneficial organisms in the garden. Cutting them up doesn’t work because all the pieces will grow back into healthy worms. To kill them — and that’s important to do — spray them with strong orange oil mixtures. Or, even better, put them in a jar with a strong orange oil mixture.

Remember, orange oil mixed stronger than 2 ounces per gallon of water will burn or even kill plants. These worms won’t hurt you, so picking them up and moving them to pavement or some kind of container is the best plan.

Question: How long can dry molasses stay on the lawn before I can get to water it?

P.R., Mineral Wells

Answer: There’s really no rush like there is with the high-nitrogen synthetic products. Just do it when you can. Foliage burn is not a concern, and the efficacy of the product doesn’t diminish.

Question: I had luscious, flowing purple and chartreuse ornamental sweet potato vines cascading out of two 24-inch urns on my front patio. No holes in the leaves, totally healthy and vibrant. All of a sudden the leaves are gone, but all of the stems remain. Now I have two urns sporting spiked strings. This happened in about a four-hour span while I slept. I have no other issues on my 2.66-acre property full of trees, plants and flowers. What do you think happened? How do I combat this?

S.H., Fort Worth

Answer: It could be rats, rabbits or squirrels. See organic repellents at Dirt


Question: We are having an infestation of grasshoppers. They’ve taken down my hollyhocks, iris and more. We’ve pulled all the weeds in our yard but can’t control our neighbors’ yards. We are using Nolo Bait to help control them. Do you have any other suggestions on how we can keep them off of our plants?

B.M., Sherman

Answer: Next season, try the combination of beneficial nematodes and Nolo Bait early in the season. For now there are two approaches, but both have a downside. Spinosad will kill the pests but will negatively affect honeybees. Spot-spray it only. The other option is kaolin clay. It works as a repellent but leaves a white particle film on plants.

Question: The city of Euless is spraying something called Biomist 4+4 ULV for mosquitoes. I looked online at the label, and it says it is highly toxic to bees. I just wanted you to know about this spraying.

B.B., Euless

Answer: You’re right. This product is a synthetic pyrethroid called permethrin and piperonyl butoxide. Both chemicals are not only toxic and harmful to honeybees but also to other beneficial insects, wildlife, pets and people. What cities should be using is a spray of essential oils and Bti (Bacillus thuringiensis ‘Israelensis’). It’s an organic mix and quite effective.


Online: Find more information about organics by using the search function on dirtdoctor.com.


Radio: “The Answer” KSKY-AM (660), 8-11 a.m. Sunday. ksky.com. The call-in phone number is 1-866-444-3478.

Mail: P.O. Box 140650, Dallas, TX 75214

Invasive Alert! Meet the New Guinea Flatworm

New Guinea Flatworm shown eating a snail

By Joshua Kutyna, Indian River Extension Program Assistant for Christine Kelly-Begazo

There is an invader amongst us, and it goes by the name of Platydemus manokwari. Better known as the New Guinea flatworm, this alien aggressor is a natural predator with no known local enemies. It dines on a variety of soil dwelling inhabitants such as snails, slugs and other beneficial invertebrates.

The first sightings of this invader were in 2015 in the Miami metro area and Coral Gables–both of which were the first discoveries ever made of this flatworm in the United States! Adult flatworms survive in pots or on plants and are transported by humans via soil, compost, rooted and potted plants and landscape waste. Not only are they an invasive species that can cause real environmental damage, but they also are known to carry a parasite called rat lungworm that can cause a form of meningitis in humans. Besides that, this flatworm produces toxic secretions that may trigger an allergic reaction in some people. There have already been 18 different confirmed observations in Indian River County since the fall of 2017.

So how can you identify one? These flatworms absolutely adore humidity and can be found in coastal, forest, urban and wetland environments. Homeowners typically find flatworms in potted plants and moist areas of their landscapes such as found under mulch or in leaf litter. They are dark brown to black with a grey/tan underbelly and a faint stripe down its backside. Adults of this species can range anywhere from 1.5-2.5 inches long and if that was not enough to induce nightmares they are also nocturnal predators and can reproduce on their own without a mate!

New Guinea Flatworm showing size

What do you do if you find a New Guinea flatworm? First and foremost, if you spot one of these foreign creatures DO NOT TOUCH them with your bare hands. Always protect your skin from coming in contact with the flatworm and any of its secretions by using gloves or a plastic bag. Nevertheless, do not let these slow-moving slimes scare you; a few simple steps can be taken to fight back against this nightmarish invader.

The most effective method of extermination is the “hot water treatment” which will kill the New Guinea flatworm but reduce casualties of the native soil dwelling animals we are trying to protect. Research has shown that pouring 109.4 degrees Fahrenheit (43 degrees Centigrade) water over the flatworm is hot enough to kill it, but snails and ants will survive. Other effective ways to kill these flatworms is to drop them into a container with alcohol, or put them in the freezer overnight and then dispose of them in the garbage. If you do spot the New Guinea flatworm, take a clear picture and communicate your discovery to Florida Fish and Wildlife Conservation Commission by phone: 888-483-4681 or on their website at IveGot1.org. You can also help track these invasive flatworms by reporting your sightings with the Early Detection & Distribution Mapping System at www.eddmaps.org/florida/report or, to find out if they have been seen in your area check out this Distribution Map.

Non-toxic flatworm, Bipalium kewense, showing dark stripe along back

The New Guinea Flatworm with pale stripe along back

Chances are the flatworms found in most Florida gardens are non-toxic species such as Bipalium kewense, which is shown left. The New Guinea flatworm’s stripe, as shown on the right, is lighter.

For more information on non-toxic flatworms commonly found in Florida, go to the University of Florida’s Entomology and Nematology Department’s Featured Creatures factsheet:

For more information on the New Guinea flatworm, go to the factsheet prepared by UF/IFAS Palm Beach County Extension:
New Guinea flatworm factsheet

Posted: July 23, 2018

On 21 March 2017, a viral post from a web site called Goodfullness.com (titled “If You See One of These Slugs Inside Your House, Dial 911 Immediately!”), argued that the invasion of the New Guinea Flatworm in Florida poses a acute risk to human health that necessitates calling 911. While this post (and many others like it) frames their invasion as a new event, it is not. This non-native species, also called Platydemus manokwari, was first spotted in August 2012 and confirmed by a team of researchers in 2015 in a scientific report that made significant news at the time:

In the USA, the accidental introduction of P. manokwari through human agency to Florida is probably recent, with our first specimens found in August 2012. The species is apparently now well established, with several different locations found in 2014 in Miami Dade County.

While viral posts implied that the discovery of a New Guinea Flatworm in one’s home necessitates a police response, authorities suggest otherwise. We reached out to the Florida Fish and Wildlife Conservation Commission to ask if their department recommended reporting sightings of the New Guinea Flatworm to 911. They told us, via e-mail, that it is not necessary:

The FWC is aware that New Guinea flatworms have spread to many parts of Florida, and people do not need to report sightings.

Indeed, the primary danger of the New Guinea Flatworm is to the ecosystem rather than to human health. The pest has an infamous track record of damaging the ecosystems to which they have been introduced, as discussed in a 2014 study on their occurrence in France:

Examined from an environmental perspective, P. manokwari has demonstrably had a serious negative impact on the biodiversity of native snail populations in the Pacific region and wherever it is deliberately or accidentally introduced it will continue to pose a threat not only to native molluscs, but possibly to other slow-moving soil invertebrates It may also indirectly have a negative impact on vertebrate species dependent upon these soil invertebrates.

From a human health standpoint, the Goodfullness.com post makes a number of assertions about the risks P. manokwari presents to humans and other, larger creatures:

These worms have the ability to consume rats and mice and when they dine on these animals, they pass on lungworm infections. From there, the infections are then transmitted to humans who are exposed to any air particles that have been contaminated by the rodent droppings.

According to Florida International University professor of biology Timothy Collins, who actively studies their occurrence in Florida, the New Guinea Flatworm does not prey on rats, and typically eats “snails, earthworms, slow-moving arthropods”.

The New Guinea Flatworm is, however, a possible carrier of a parasite that passes through the feces of rats — the rat lungworm (Angiostrongylus cantonensis). This parasite generally causes mild symptoms that generally resolve without treatment, but is capable of a more serious infection called eosinophilic meningitis, according to the CDC:

Some infected people don’t have any symptoms — or have only mild symptoms that don’t last very long. Sometimes the infection causes a rare type of meningitis (eosinophilic meningitis). The symptoms can include headache, stiff neck, tingling or painful feelings in the skin, low-grade fever, nausea, and vomiting.

The rat lungworm, as it turns out, utilizes a complex life cycle which requires three hosts, one of which can be a flatworm or snail, as described in a 2012 review of the parasite:

When rats eat infected slugs or snails, they ingest third stage larvae which eventually grow to sexual maturity and reproduce in the heart. Single-celled eggs hatch in the lung, and first stage larvae migrate up the bronchial tree, are swallowed, and 6–8 weeks after infection are excreted with feces.

Slugs or snails then eat rat feces and acquire the first stage larvae. Slugs and snails are obligatory intermediate hosts which support parasite development from the first to the third larval stage.

If one’s food were to accidentally come in contact with the mucus of an infected flatworm, or if one were to directly consume the animal itself, you could potentially contract a rat lungworm infection, Collins told us via email:

Angiostrongylus cantonensis, or rat lungworm, is carried by many animals, including Platydemus. For example, it has been reported in the Giant African Land Snail in Florida. There are published medical cases of people becoming infected with Angiostrongylus after eating lettuce over which snails infected with Angiostrongylyus have crawled.

He tempered this analysis, however, with the caveat that there have yet to be any confirmed cases of the New Guinea Flatworm carrying the rat ringworm in Florida, and provided us with this simple advice:

The average person can avoid risk by not handling the flatworms, or if they do, by not putting their hands near their eyes or nose before cleaning them carefully. In addition to the health risk, Platydemus have been reported by some brave soul to taste terrible, so eating them is a bad idea all around.

This advice is in line with the CDC’s position as well:

Don’t eat raw or undercooked snails or slugs, frogs or shrimp/prawns. If you handle snails or slugs, wear gloves and wash your hands. Always remember to thoroughly wash fresh produce. When travelling in areas where the parasite is common, avoid eating uncooked vegetables.

This invasive creature is a big problem for local ecosystems, and it is an issue that Collins and other scientists are actively researching. However, while there are indirect potential risks to humans from the New Guinea Flatworm in Florida, these risks in no way necessitate calling 911.

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Toxic New Guinea flatworm surfaces in Loxahatchee

A nasty-looking worm is making its way throughout Florida, just a year after the invasive species entered the state.

Now, local pest control companies and the Florida Fish and Wildlife Commission are confirming a report of the New Guinea flatworm found in Loxahatchee.

Jeannie Tilford is usually hunting for cane toads while she runs her local business,Toad Busters.

“Thousands of invasive species here. Florida is a great place for things to survive,” she said in an interview with WPTV on Wednesday.

But lately, she’s been dealing with another nuisance.

“I am holding two New Guinea flatworms,” she said, wearing protective gloves.

She found several of them at her friend’s house in Loxahatchee.

“They’re pretty gross. And they have toxic slime, that if you get it on your skin, it will actually cause an allergic reaction,” said Tilford.

The flatworm has a dark, slender body with a distinct orange or tan colored stripe down it’s back.

The species comes from the South Pacific and last year, somehow slithered into Miami through plant shipments.

“When we get plants from nurseries from Miami, which is a big port of entry, those plants and flatworms come in on the plants, you put the plant in your garden and you’ve now transplanted an invasive species into your area,” said Tilford.

The worm even sparked rumors on the Internet that people should call 911 if they see one. FWC said that’s not true but they are encouraging people to help the agency keep track of the worm by contacting FWC’s Exotic Species Hotline at 1-888-IVE-GOT1 (1-888-483-4681).

Jamie Vasquez, a branch manager with Tropical Pest Control in West Palm Beach, said it’s the same worm that transmits the deadly rat-lungworm parasite, which can lead to a disease that causes meningitis.

“The rats will defecates and snails will eat the feces. And then the flatworm will eat the snails. It’s a cycle that repeats within themselves,” he said. “If a rodent infestation occurs in your house, and they chew through the a/c vents in your house, they can defecate in the vents and that can transmit to human also through air particles.”

The worms can also crawl on fruits and vegetables.

“If you don’t wash them, you can contract meningitis that way,” Vasquez added.

Experts advise families to keep an eye on your kids and pets in the yard. When your kids come inside, make sure they wash their hands.

“It’s really easy to be working in the garden and not wash your hands and have contact with eggs of this species,” said Tilford.

The worms like to hide in areas with lots of moisture, such as air conditioning units, water sprinklers or water hoses.

Experts recommend the surefire way to kill the worm is by pouring boiling water on it. Use a plastic bag to pick up and dispose of the body.

“You’re killing the worm and you’re drying it up,” said Tilford. “Some people right away want to think, ‘Oh let me throw bleach down or poisons on it.’ You’re adding more things to the ground and if it doesn’t have an effect on the worm, it’s not going to help.”

FWC sent the following statement to WPTV regarding the find in Loxahatchee.

“Based on the description and photographs of the species we received, we believe it is a New Guinea flatworm. However, genetic analysis would need to be conducted to confirm the identity of the species,” it reads.

While FWC tracks its spread, Florida and Hawaii are so far the only states with the worm. The species is A-sexual, so it doesn’t take long to spread fast.

“They can mate on their own. They don’t need much! They’re resilient,” said Vasquez.

If you find a flatworm, take a picture and submit a report by clicking here.

There’s also a map that shows where the flatworm has been spotted throughout Florida by clicking here.


Marine Polyclad Flatworms

Polycladida (Order) > Acotylea (Suborder) > Leptoplanoidea (Superfamily) > Leptoplanidae (Family)

Leptoplana tremellaris (Müller OF, 1773)
– A leptoplanid polyclad turbellarian
Leptoplana tremellaris (Müller OF, 1773) ?
– A leptoplanid polyclad turbellarian

Polycladida (Order) > Acotylea (Suborder) > Leptoplanoidea (Superfamily) > Pleioplanidae (Family)

Pleioplana atomata (Müller OF, 1776) ?
– A pleioplanid polyclad turbellarian

Polycladida (Order) > Acotylea (Suborder) > Leptoplanoidea (Superfamily) > Stylochoplanidae (Family)

Comoplana ?
Comoplana agilis (Lang, 1884) – A Marine Flatworm
Comoplana ? sp. 1 – A Marine Flatworm
Both the above found with Stylochoplana maculata, it is possible that the turbellarians above may be varients of this species. An expert opinion is needed.

Stylochoplana maculata (Quatrefage, 1845)
– A marine flatworm

Polycladida (Order) > Cotylea (Suborder) > Euryleptoidea (Superfamily) > Euryleptidae (Family)

Cycloporus papillosus (Sars, 1878)
– A euryleptid polyclad turbellarian

Eurylepta cornuta (Müller OF, 1776)
– A euryleptid polyclad turbellarian

Oligocladus sanguinolentus Lang, 1884
– A euryleptid polyclad turbellarian

Prostheceraeus vittatus (Montagu, 1815)
– Banded or Candy-striped flatworm

Stylostomum ellipse (Dalyell, 1853)
– A euryleptid polyclad turbellarian

Polycladida (Order) > Cotylea (Suborder) > Euryleptoidea (Superfamily) > Prosthiostomidae (Family)

Prosthiostomum siphunculus (Delle Chiaje, 1822)
– A marine flatworm

Triclad Flatworms (Tricladida)

Tricladida (Order) > Maricola (Infraorder) > Cercyroidea (Superfamily) > Cercyridae (Family) > Cercyrini (Subfamily)

Sabussowia dioica (Claparède, 1863)
– A marine triclad flatworm

Tricladida (Order) > Maricola (Infraorder) > Procerodoidea (Superfamily) > Procerodidae (Family)

Procerodes littoralis (Ström, 1768)
– A marine triclad flatworm

Parasitic Flatworms

Fecampia erythrocephala Giard, 1886
– Parasitic crab flatworm (cocoons)
Fecampia erythrocephala Giard, 1886 ?
– Parasitic crab flatworm in adult Palaemon prawn hosts
Fecampia erythrocephala Giard, 1886 ?
– Parasitic crab flatworm in an ampithoid amphipod host

Possibly a species of Opechona – A parasitic trematode that includes the hydroid Leuckartiara octona as a host in its complex multi-host life cycle.

Platyhelminthes (Phylum) > Neodermata (Subphylum) > Trematoda (Class) > Digenea (Subclass)

The encysted metacercaria stage of a trematode digenean parasite on the fish, Cyclopterus lumpus, the Lumpsucker; Opechona bacillaris (Molin, 1859) Dollfus, 1927 ?

Probable new species of parasitic turbellarian on
the opisthobranch mollusc Runcina coronata

Other Flatworms

Xenacoelomorpha (Phylum) > Acoelomorpha (Subphylum) > Acoela (Order) > Convolutidae (Family)

Convoluta convoluta (Abildgaard, 1806)
– An acoela flatworm (specimen 1)
Convoluta convoluta (Abildgaard, 1806)
– An acoela flatworm (specimen 2)
Specimen two likely to be older than specimen one due to the presence of white markings on the body.

Rhabditophora (Class) > Eulecithophora (Infraclass) > Prolecithophora (Order) > Plagiostomidae (Family)

Plagiostomum sulphureum Graff, 1882 ?
– A plagiostomid flatworm
Plagiostomum vittatum (Frey & Leuckart, 1847)
– A plagiostomid flatworm

Vorticeros auriculatum (Müller OF, 1784)
– A plagiostomid flatworm
Vorticeros luteum Hallez, 1879
– A plagiostomid flatworm

Unidentified Prolecithophora
On Bladder Wrack from Mousehole, Cornwall. 13.08.16.
Small white and orange striped flatworm similar
looking to the mollusc genus Rhodope. 21.03.15.

Astrotorhynchus bifidus (McIntosh, 1874)
– A trigonostomid flatworm

Polycystis naegelii Kölliker, 1845 ? – A marine flatworm

Monocelis lineata (Müller OF, 1773) – A marine flatworm

Help needed with identity
Turbellarian in Pearlsides, Maurolicus muelleri. 13.03.14.
Small white and orange striped flatworm similar
looking to the mollusc genus Rhodope. 19.04.15.
Yellow marine flatworm, Croyde, North Devon. 17.09.16.
Plagiostomum vittatum ? Penzance. 20.05.15
Blue marine flatworm found at Marazion 19.04.15.
Orange striped flatworm Battery Rocks. 02.04.17.
Orange striped flatworm Chimney Rocks, 17.04.15.
Small flatworm found at Newlyn Marina 07.01.17.
Small flatworm Newlyn Harbour slipway 08.04.15.
Small flatworm Newlyn Harbour slipway 18.10.16.
Flatworm specimen (1) from Hayle. 19.07.15 / 07.06.18.
Flatworm specimen (2) from Carnsew Pool 19.07.15.
Flatworm specimen (3) from Carnsew Pool 19.07.15.
Flatworm specimen (4) from Carnsew Pool 19.07.15.
Microscopic flatworm found in Newlyn Harbour 02.01.14.
Yellow flatworm found at Newlyn Harbour 01.09.15.
Orange flatworm – Newlyn Marina 11.08.15.
Flatworm found at Newlyn Marina 11.07.15.
Flatworm found at Newlyn Marina 04.05.15.
Flatworm found at Newlyn Marina 29.04.15.
Flatworm found at Newlyn Marina 02.10.14.
Flatworm found at Newlyn Marina 06.09.16.
Flatworm found at Newlyn Marina 22.10.18.
Flatworm found at Skern, Westward Ho! 12.04.17.
Small flatworm on algae from Penzance Harbour 11.05.13.
Flatworm found at Sennen Cove, Cornwall. 15.10.12.
Is this a cocoon forming Flatworm ? Pelagic ?

Marine flatworms are notoriously difficult to identify, many needing to be dissected and microscopically examined. The date and habitat where the flatworm was found is also very important information when identifying them; e.g. some may be more frequently on the middleshore close to mussel colonies, others in less saline situations.

Freshwater Flatworms

Tricladida (Order) > Continenticola (Suborder) > Planarioidea (Superfamily) > Planariidae (Family)

Polycelis felina (Dalyell, 1814) – A freshwater flatworm

For more images of flatworms visit the following sites APHOTOFAUNA and Roscadghill Parc Wildlife.

Sealife Survey
Record UK marine life using the the Marine Biological Association’s Sealife Survey (external link)

PotWatch, is a Buglife campaign to highlight the role the importation of pot plants plays in establishing invasive species in the UK. In the first stage of this campaign they are asking people to record countries of origin of plants they purchase at their local garden centres.

Buglife would also like you to keep a look out for flatworms in the plants you purchase. To help you they’ve created a basic guide to flatworms downloadable from the Potwatch survey webpage. When you’re re-potting your plants keep an eye out for flatworms and their eggs and send in photos of any you find.

Flatworms Versus Earthworms

Non-native flatworms can pose a risk to native earthworm populations if the species has a taste for earthworms. We’ll introduce you to three earthworm-eating non-native flatworms below, but please check out the Buglife Non-native Land Flatworms guide for more details on these species and others (including ID tips).

New Zealand Flatworm

The New Zealand Flatworm (Arthurdendyus triangulatus) originates, unsurprisingly, originated from New Zealand and was introduced to the UK as far back as the 1950’s (likely through imported plants). It feeds on earthworms that emerge from the ground to feed at night (the deep-burrowing anecic species, such as Lumbricus terrestris) and can be found taking refuge under stones, wood or even polythene.

Unlike most other earthworm predators the NZ Flatworm can enter an earthworm burrow,rendering anecic earthworm’s main defense mechanism against predation relatively futile. The NZ Flatworm requires damp, cool conditions to survive and cannot survive in dry soils.

The NZ Flatworm has a widespread distribution and is relatively common in Scotland and Northern Ireland.

More info: NZ Flatworm Species Factsheet on the GB Non-Native Species Secretariat website

Australian Flatworm

The Australian Flatworm (Australoplana sanguinea) is another earthworm-eating flatworm, this time originating from Australia. The first record of this species in the UK dates back to 1980 on the Isles of Scilly, again thought likely to have been introduced through imported plants. It’s diet is thought to be solely earthworms and it can affect earthworm population structure, with some species being more affected than others.

The Australian Flatworm is widespread in South West England, and when present at a site can be abundant in numbers. It is usually found under stones, planks, plastic sacks and other refuges on the soil surface.

More info: Australian Flatworm Species Factsheet on the GB Non-Native Species Secretariat website

Obama Flatworm

The Obama Flatworm (Obama nungara) is a relatively recent introduction to the UK, originating from Brazil. This non-native flatworm is already a threat to agriculture across France, and was found in a pot plant at a garden centre in Oxfordshire in November 2016. It was first found in Europe on Guernsey in 2008, but has spread through France and into Spain and has now been discovered at a handful of locations in the UK.

A known predator of earthworms and land snails, there is very little additional information on the current status of this species in the UK.

More info: Obama Flatworm Species Factsheet on the GB non-Native Species Secretariat website

New Zealand flatworms

The New Zealand flatworm was first introduced to the UK in the 1960s, although it has never become as great a problem as was originally feared. It’s purple-brown on top, and flat and pointed at both ends. When resting it coils up, is covered in mucus, and is about 1cm wide by 6cm long, although when extended it can be up to 30cm long. It lives on earthworms, covering them in digestive juices to dissolve them before sucking them up. The larvae of ground beetles prey on flatworms.


Researchers are eager to know of new sightings. Should you discover a possible flatworm in your garden, please take a digital photograph and email it to [email protected] When taking photos, place an object such as a pencil, or a key, alongside the creature to provide scale.


The numbers of our native earthworm are declining thanks to this invasive worm – it loves to feast on them.

Find it on

undisturbed ground, under stones, logs and pots. Prefers cool, damp habitats.



Check sites where they like to hide undisturbed – for example under stones and pots – and dispose of any you find. Where there’s one, invariably you’ll find more. Where they are present, spread a sack on the ground, weigh it down and keep checking if more are hiding beneath. Eggs are usually found between June and September. Destroy the worms by squashing or dropping them into salty water.

Gardens: Dealing with the dreaded New Zealand flatworm

Flatworms are between 5 and 15cm long, flat with a dark purply brown topside and a creamy pale underside and edge. They’re pointed at both ends and, like slugs and snails, leave a sticky mucus trail behind them. In summer, they lay an egg every 7-10 days, with each usually containing 6 or 7 young. Look out for these shiny, blackcurrant-like cocoons.

I know people are surprised that their earthworm population never seems to recover, imagining the flatworms would die out once they’d disposed of their prey. The answer is horribly simple. The predators degrow, shrinking to as little as 10% of their original body weight, until a new source of food lets them regrow again.

Flatworms are present throughout Scotland, with sightings in Glasgow, Ayr, Inverness, Dingwall and Castle Douglas to name a few. So, wherever you live, vigilance is essential to keep them out of your own garden.

Flatworms can travel between gardens, so if a neighbour’s garden is infested, you must be especially watchful, setting traps close to a boundary fence. They shelter in cool, damp places, so place slabs of wood or stone there, lift them regularly and put flatworms in warm, very salty water to kill them.

You should also check pots of new plants. Nursery and garden centre stock should be perfectly safe, but take care with any from friends or a plant exchange. And, if you do have flatworms, never give any plants to friends. Place a pot in a bucket of warm water,?30C, for 40 minutes to kill adults.

This treatment won’t affect eggs, so the alternative is to remove the plant from its pot. Over a large bowl or bucket, wash away the soil to flush out any adults or eggs. Dispose of the soil safely and not into the garden or compost heap.

If you have a resident flatworms, keep trapping, as I describe above. You will gradually reduce their numbers and there may be a small recovery in earthworm population, but don’t hold your breath. Trials have been conducted which show that potential predators, rove beetles, Staphylinidae, and ground beetles, Carabidae, are reluctant consumers. I’m afraid your only long term solution may be a visit to an estate agent.

On a more positive note, you can help researchers better understand flatworms, in the hope that some solution may be found.

Dr Annie Robinson of Aberdeen University and Dr Brian Boag from the James Hutton Institute, Dundee are running a research programme to find out how far and widely flatworms have spread and the effects on local environments.

The project is part of a UK-wide citizen science initiative, OPAL, Open Air Laboratories. In this case, they’d like gardeners to report and photograph flatworm sightings, and would also be interested to hear of unaffected places.

Dr Robinson says: “Carrying out the survey is really straightforward. Search your garden, allotment, school grounds or public spaces for 10 minutes, focussing on dark damp places like under pieces of wood, stones or plastic. If you think you have found a New Zealand Flatworm, please take a photo and submit it along with its location via the OPAL website: www.opalexplorenature.org/nzflatworm

Since the project started in 2015, 1500 people have taken part and the scientists would especially welcome information from Orkney, Shetland, Skye, the Western Isles, Caithness, Fort William, Dumfries and Galloway and the Borders.

Jobs in the fruit garden

Check stakes, supports and tree ties for wind rock or constriction. Replace or renew as necessary. Cut out dead, dying or infected branches from apple and pear trees, but not stone fruits like plums and cherries. Clear away weeds and grass from around young trees to reduce competition.

Pick off any remaining fruit from trees as they can harbour disease. Entice birds into the fruit garden with feeders and fatcakes. They help control overwintering aphids and cocoons.

If a fan-trained peach has been infected with leaf curl, build a simple rain-proof structure to keep rain off newly forming buds in early spring.

Plant of the Week

Calendula officinalis ‘Indian Prince” is still flowering bravely. Cheerful, deep orange petals with tawny backs glow brightly whatever the weather.

One of the worst aliens that arrived in Ireland is the New Zealand Flatworm. Every gardener should be worried about them because they feed almost exclusively on our beloved earthworms. We all know that without the hard and continuous work of earthworms our soils would simply collapse. They will quickly become compacted and waterlogged. Worms eat their way through the soil mixing crop residues and anything else that is decaying with the soil and by doing so they create little drainage channels for the water to infiltrate. Even Charles Darwin wrote his first book about the importance of earthworms. Worms are really our best friends in the garden and every gardener should do anything possible to encourage worms into the garden.

Unfortunately our native earthworms are in danger from this alien species – the New Zealand flatworm. It was first found in 1963 in Northern Ireland. It possibly came in with plant imports as it like to live under pots. It has since spread to most areas of Scotland and many wetter counties in Ireland as it thrives in wet conditions.

What do they do?

The New Zealand Flatworm is a lazy creature. It plays no part in soil improvement as it just follows the passages the worms have made. In fact, it can make itself as small as the tip of a needle. Many years ago I caught a dozen flatworms in a garden in Scotland, put them in a jam jar with a pierced lid and a muslin cloth tied around. The next day they had all escaped.

The New Zealand Flatworm follows the earthworms or even waits until they come near and then climbs on worms’ back, injects something into it and the worm turns into a ‘soup’ and will then be sucked out by the flatworm. Not nice, really.

How to find out if you have it?

You will have to look under heavy stones, black plastic, large pots, water barrels, especially in the wetter parts of your garden. The following website has good images of the flatworm so you can easily identify it.

Be responsible!

If you have the New Zealand Flatworm in your garden you should not spread it around to your friends.

– Do not give away potted plants that have stood on the ground

– Do not divide plants and share them out


There is no chemical control available and quite luckily so as it would also kill your earthworms.

The best way is to trap them under stones etc and collect them regularly. You should also to remove other habitats that you won’t be able to check.

To make matters even worse, the Australians have also sent over their flatworm. It is less common, but keep an eye out for it.

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