You have probably seen them in your basement or garden, for they live under stones and bark in damp places. While they exist in large numbers here in North America, they also reside in the wettest areas of Germany.
Biogeographic Regions: nearctic (Native ); palearctic (Native )
Regularity: Regularly occurring
Type of Residency: Year-round
Their light shell-like crustaceous exterior is usually a drab earthy color. Pill bugs found in North America range from gray to brown. However, those with habitats in Europe have large red dots, which give them protection by conferring a resemblance to black widow spiders. Pill bugs have five abdominal segments which are distinct dorsally. Their first antennae are vestigial.
Pill bugs hide in damp places during the day and are active at night. Under moist areas such as bark and stones, they make their burrow (living quarters.) One of the pill bugs' most surprising characteristics is that they have such a wide distribution pattern. "Home" can be a forest, garden, or basement.
Terrestrial Biomes: savanna or grassland ; forest
Depth range (m): 229 - 1646
Depth range (m): 229 - 1646
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Habitat Type: Terrestrial
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
A. vulgare, like most isopods, are omnivorous. They feed on fungi, live or dead plants and animals. Special treats for pill bugs are monocotyledonous leaves. All isopods increase decomposition by processing leaves through their alimentary canal. It is not uncommon for pill bugs to shift from one type of food to another, for during a drought they turn from being vegetarians into scavengers.
Primary Diet: carnivore (Scavenger ); herbivore (Folivore , Frugivore ); mycophage ; detritivore
These animals are part of the community of species that break down dead plants and animals.
Ecosystem Impact: biodegradation
- Pillbugs and sowbugs have microbes in their guts that allow the crustacean to digest plant material.
They are famous for curling up into a tight ball for a defense mechanism. Some may secrete a substance which discourages spiders. The most common defense among all of them is to remain inconspicuous.
- anything that eats invertebrates
Life History and Behavior
A. vulgare reproduce on land as opposed to in water. Eggs develop in a brood pouch filled with fluid, from which fully developed young are released. They produce between one and two broods. The number produced depends on the size and condition of the female, who may cease to grow under stress due to excessive hydration, which reduces the chance of a second reproduction. Ironically, when the food supply is short, the offspring grow larger.
Molecular Biology and Genetics
Statistics of barcoding coverage: Armadillidium vulgare
Public Records: 1
Specimens with Barcodes: 15
Species With Barcodes: 1
Barcode data: Armadillidium vulgare
There is 1 barcode sequence available from BOLD and GenBank. Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen. Other sequences that do not yet meet barcode criteria may also be available.
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Download FASTA File
Pill bugs are quite common and have no special conservation status.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
NatureServe Conservation Status
Rounded Global Status Rank: GNR - Not Yet Ranked
Relevance to Humans and Ecosystems
Economic Importance for Humans: Negative
Pillbugs may occasionally eat small plants as they germinate, causing some trouble in gardens.
Economic Importance for Humans: Positive
Pill bugs living in gardens help circulate soil, although they may also eat small plants.
Armadillidium vulgare, the (common) pill-bug, (common) pill woodlouse, or rolly polly, is a widespread European species of woodlouse. It is the most extensively investigated terrestrial isopod species.
Armadillidium vulgare may reach a length of 18 millimetres (0.71 in), and is capable of rolling into a ball when disturbed; this ability, along with its general appearance, gives it the name pill-bug and also creates the potential for confusion with pill millipedes such as Glomeris marginata. It can be distinguished from Armadillidium nasatum and Armadillidium depressum, the only other British species in the genus, by the gap that A. nasatum and A. depressum leave when rolling into a ball; A. vulgare does not leave such a gap.
Armadillidium vulgare is able to withstand drier conditions than many other woodlouse species, and is restricted to calcareous soils or coastal areas. It feeds chiefly on decaying plant matter, but also grazes lichens and algae from tree bark and walls.
It is able to regulate its temperature through its behaviour, preferring bright sunshine when temperatures are low, but remaining in shadow when temperatures are high; temperatures below −2 °C (28 °F) or above 36 °C (97 °F) are lethal to it. A. vulgare is less susceptible to cold during the night, and may enter a state of dormancy during the winter in order to survive temperatures which would otherwise be lethal.
The native distribution of A. vulgare ranges across Europe, especially in the Mediterranean region . In the United Kingdom, A. vulgare is very common in southern and eastern England, but is more confined to coastal areas in the north. Similarly, in Ireland, A. vulgare is common in the south and east, but rarer in the north and west.
A. vulgare has been introduced to many locations in North America, where it may reach population densities of up to 10,000 individuals per square metre. It is now one of the most abundant invertebrate species in California coastal grassland habitats. It has also been introduced, to a lesser extent, to sites across the world.
Relationships with humans
Because of their unusual yet non-threatening appearance, some Armadillidium vulgare are kept as pets in areas throughout the U.S., typically among children. Among adults, they are often seen as unwanted (but essentially harmless) home pests. Keeping a pet pill bug requires a very moist habitat with limited light and lots of decaying plant matter. They can often live up to three years.
|External identifiers for Armadillidium vulgare|
|Encyclopedia of Life||1021952|
|Also found in: Wikispecies|
|Wikimedia Commons has media related to Armadillidium vulgare.|
- "Armadillidium vulgare". Integrated Taxonomic Information System.
- Helmut Schmalfuss (2003). "World catalog of terrestrial isopods (Isopoda: Oniscidea) — revised and updated version". Stuttgarter Beiträge zur Naturkunde, Serie A 654: 341 pp.
- "Pill woodlouse (Armadillidium vulgare)". ARKive.org. Retrieved February 13, 2009.
- "Woodlouse Wizard: an identification key". Natural History Museum. Retrieved November 7, 2010.
- "Common pill woodlouse — Armadillidium vulgare". Natural England. Retrieved February 13, 2009.
- Roberto Refinetti (1984). "Behavioral temperature regulation in the pill bug, Armadillidium vulgare (Isopoda)". Crustaceana 47 (1): 29–43. doi:10.1163/156854084X00298.
- "Armadillidium vulgare". Natural History Museum. Retrieved November 7, 2010.
- "Grid map of records on the Gateway for Common Pill Woodlouse (Armadillidium vulgare)". NBN Gateway. Retrieved February 13, 2009.
- Jan Frouza, Richard Lobinske, Jirí Kalcík & Arshad Ali (2008). "Effects of the exotic crustacean, Armadillidium vulgare (Isopoda), and other macrofauna on organic matter dynamics in soil microcosms in a hardwood forest in central Florida". Florida Entomologist 91 (2): 328–331. doi:10.1653/0015-4040(2008)91[328:EOTECA]2.0.CO;2.
- Oscar H. Paris (1963). "The ecology of Armadillidium vulgare (Isopoda: Oniscoidea) in California grassland: food, enemies, and weather". Ecological Monographs (Ecological Society of America) 33 (1): 1–22. doi:10.2307/1948475. JSTOR 1948475.
- Smith-Rogers, Sheryl (October 2009). "Wild Thing: Roly-Poly Pillbugs". TPW Magazine. Retrieved July 10, 2010.
- Stanley A. Schultz & Marguerite J. Schultz (2009). The Tarantula Keeper's Guide: Comprehensive Information on Care, Housing, and Feeding. Barron's Educational Series. pp. 181–183. ISBN 978-0-7641-3885-0.