Sleeping Bipalium Kewense. Photo by A. Layton Funk	What's Eating Your Worm Bin? B. adventitium   B. kewense   C. coerulea   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)

http://www.google.com/search?q=%22Bipalium+adventitium%22

Photographed in Cary, NC on November 7, 2008. One of ten 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

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

Photographed in Cary, NC on November 4, 2008. Only one 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, so it may be a while till chow time. Stay tuned for further developments.

O. moreleti is a stout, black species to 40 mm long. It is native to the Iberian Peninsula and is known in Australia as the Portugese millipede. In Adelaide it has been a household pest for some 20 years, and west of Melbourne it has stopped trains by swarming over the rail lines. As with many introduced species, the 'boom' in O. moreleti populations in particular areas has been followed several years later by a 'crash' to much lower numbers. For an overview of Australian research on this species, see Bailey (1997).

Mass occurrences of this species are usual in autumn (and sometimes in spring) in Hobart, Launceston, Burnie and Devonport. In all of these places O. moreleti enters houses, which is not surprising given that Portugese millipede populations in some backyards are of the order of 1000 - 5000 individuals. Nevertheless, it is highly unusual to find O. moreleti more than half a kilometre from a Europeanised habitat, and I have yet to find this species in undisturbed bush in Tasmania. It has been present in the State at least since the mid-1970s. The map below shows only some of its known localities.

(Some) localities for O. moreleti. Scale bar = 100 km.
For an interactive map with more up-to-date localities, go to the mapper page.

More information:
 
Biology - Bailey (1997)
Distribution, conservation and general - Taylor et al. (1997)

terrestrial molluscs

http://www.google.com/search?q=barker+natural+enemies+molluscs

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.