Sleeping Bipalium Kewense. Photo by A. Layton Funk	B. adventitium   B. kewense   C. coerulea   Unidentified in Cary   As yet Unknown   The North American Piedmont's Terrestrial Planaria Flatworms Specimens found at North 35.78 - West 78.78°
	Professional landscapers, responding to a demand for lollipop tree scenescapes, accidentally brought them from all over the world. They are now here to stay, changing our ability to sustainably produce food in ways we do not yet understand.

Near the bottom of the planet's food pyramid is the lowly earthworm, munching soil litter, aerating the soil, and generally keeping the carbon cycle in as tight a loop as possible.

Earthworms feed much of the food chain, having many, many predators. New to this continent, introduced from southeast Asia, are the land planaria of the Bipalium genus. Lacking the powerful contractive musculature earthworms use to tunnel in even highly compacted clay soils, they are nonetheless perhaps more highly adapted to hunt earthworms than any other.

All planaria eat meat, but their preferences for prey vary. Although their dietary habits have not yet been fully identified, even by experts like Dr. Peter Ducey, some seem to attack slugs and snails highly preferentially over earthworms. While either of these gastronomies probably has negative effects on both biodiversity and biomass here in America, gardeners may be excused in thinking this order separates into "good guys" and "bad guys" in how we raise food.

Why do we need to relate to this recent ecological development from an informed position?

• It is unclear if land planarians have a natural antagonist in our environment. Their slimy secretions appear to be distasteful, if not toxic.
• Given adequate food, moisture and warmth, they are prolific. Each worm can produce tens of egg cases, each containing up to seven embryos.
• Even more significant, one to two days after feeding they spontaneously fragment into two, each anterior and posterior section of which becomes a clone.
• Like starfish, cutting them to pieces simply produces a viable individual from each piece.
• Even among professionals, there is a great deal of mis-identification.

Bipalium adventitium   -   Return to Top

Order Tricladida -> Bipaliidae -> Bipalium -> B. adventitium (Hyman 1943)

Photographed in Cary, NC on November 7, 2008. One of 19 found here so far. Possibly a native of southeast Asia, B. adventitium was described in 1943 from worms found in California. Probably imported to North America during the 1900s with horticultural plants. We have directly confirmed predation on earthworms. They are reported to readily consume earthworms outweighing themselves by up to 55X and gaining 52% of their prefeeding mass during a feeding bout.

Bipalium kewense   -   Return to Top

Order Tricladida -> Bipaliidae -> Bipalium -> B. kewense

Photographed in Cary, NC on November 8, 2008. At a ratio of about 30:1, by far the most common flatworm we have found here. Discovered in 1878 in the greenhouses of Kew Gardens near London, hence its scientific name. Possibly native to the Indo-Malayan region of southeast Asia, B. kewense was imported to North America during the 1900s with horticultural plants. We have directly confirmed predation on earthworms. Five parallel dark stripes; the center stripe is razor-thin, except where it broadens at mid-section.

Caenoplana coerulea   -   Return to Top

Order Tricladida -> Terricola -> Geoplanidae -> Caenoplana -> C. coerulea vaga (Stimpson, 1857)

Photographed in Cary, NC on November 4, 2008. Only three found so far. ~7cm in length. Head is tapered, not lunate. Dark blue to black ground with single pale stripe. Ventrum is a lighter blue. Thought to be a generalist predator of gastropods, arthropods, diplopods and earthworms, it is known to feed on the Tasmanian millipede Ommatoiulus moreleti. Our sole specimen has refused snail, slug and earthworm.

Note: Due to a printer error, editor Gary M. Barker, in color plate 15 of Natural Enemies of Terrestrial Molluscs, following p. 278, identifies this worm as Platydemus manokwari. According to the author, Leigh Winsor, the legends of plates 15 and 16 should be swapped.

Unidentified Flatworms Found Here   -   Return to Top

Order Tricladida -> Rhynchodemidae -> Microplana?

Photographed in Cary, NC on April 15, 2009. Only two found so far. ~4cm in length. Body slightly irregular, more tapered anteriorly, head not lunate. Dark, almost black dorsum with gray ventrum. While this is possibly a member of Microplana Peter Ducey indicates this may be any of several midsized land planaria, and cannot be positively IDed without close examination.