365 Urban Species. #093: Woodlouse

[urbpan]

Urban species #093: Wood louse Oniscus asellus

First, let's address the name problem. We can call these animals woodlice or sow bugs if they can't roll into a defensive ball. If they can roll into a defensive ball, we can call them pill bugs. We can call all of them terrestrial isopod crustaceans, or even oniscideans, if we want to be scientifically correct, but in the interest of simplicity, I'm leaving behind the following common names: roley-poley/roly-poly, potato bug, armadillo bug, slater, ball bug, chuggy pig, butcher boy, carpenter, woodbug, hardy back, doodle bug, and cheeselog. You may collect yours when we're done, and use it as you please.

There are over 3000 known species of them, but there are just a handful that are urban. Pictured is the "shiny European sow bug," identified by its relatively large size (reaching just under 2 cm) and glossy dark-gray surface, as well as a host of more difficult-to-see features. The other common species are the "rough woodlouse,"Porcellio scaber, the soft matte gray colored one that I saw so much when I turned over logs as a boy, and Armadillidium vulgare, the common pill bug, which I have never seen in New England, though I am often assured that it is here. These three species are likely to have been originally natives of Europe, but are naturalized practically everywhere, and don't seem to be bothering anybody in their new homes. Most people rarely encounter these secretive animals, unless they deliberately seek them out, or have an especially moist home.

As the only large group of fully terrestrial crustaceans (relatives of crabs and lobsters rather than insects or millipedes), they need to keep their bodies wet to some degree or another. Their breathing apparatus allows water to be easily lost from their bodies, so they tend to stay where it is always damp. They are nocturnal, and will move away from a light that is shined on them.They eat vegetation, detritus, and fungi, and are generally considered to be beneficial soil-producing decomposers, though some gardeners complain of woodlice eating their plants. Found indoors they are a symptom, not a problem: some wood in your house is probably rotting.

Woodlice are being studied as living indicators of certain pollutants. Heavy metal contamination can be detected and quantified by examining its effects on these creatures. In my research I haven't answered one question I've had for a long time: When my brother's yard is sprayed with pesticides to control black widow spiders, how come the woodlice survive?

Comments

[lisianthia.livejournal.com]

I think I used to call these "roly poleys" when I was little.

[ankhanu.livejournal.com]

Excellent entry.
I never really know what to call these things... I've never been happy with any of the common names; but woodbug or wood louse are most commonly used.

[artemii.livejournal.com]

depends on what the pesticide is and where/how it's sprayed.

these lived in my sandbox when i was a child. at the time i thought it was really cool to put them on my arms and let them run around till they did what as an adult i know was a terrified dive off my elbow for the darkness and dampness of the sandbox, but as a child i thought was a cool maneuver full of panache.

a soil ecology book i once read talked about certain invertebrates' carcasses as important carbon sinks in home gardens, but i can't remember if these were among them.

[drocera.livejournal.com]

Huh - I learned something new today! I didnt know they were crustaceans!

[markurock.livejournal.com]

Hey Urb... and all, I've just done the write up on the Sowbug (a.k.a. woodlouse) for the Woodland Park Zoo guide book. They have them in the "BUG" World! exhibit along with Yellow (Red) Spotted Millipedes (Harpaphe heydeniana heydeniana) and the Cross Orbweaver Spider (Araneus diadematus)! It is a cool little exhibit made to look like the average patch of back yard or wooded area here in the Pacific Northwest.
We also have Pillbugs and Potato Bugs, but I don't have their info close at hand.
It is cool to know that the sowbug/ woodlouse looks totally "bug", but is really more like a crab, lobster, crayfish or barnacle!
We have so many animals running for state bird, maybe we could nominate the woodlouse along with the slug and mosquito!

[pinkveneer.livejournal.com]

hi, just received your very nice pamphlet! reading little by little...
did you produce it yourself? it's well done :) if not, care to give details? i haven't seen such nice folding job and teeny staples and i might need those for a future project. thoughts? and thanx for any info you care to give...

[urbpan.livejournal.com]

cottonmanifesto did the art direction, I did almost all the writing, Gnomon copy did the copying, folding and stapling.

I own a saddle-stitcher (long-arm stapler) but I've done enough zines in my life that I could see that 25 cents an issue for folding and stapling was a bargain.

Any other info I can give I'll be happy to. ask away!

[pinkveneer.livejournal.com]

many thanx! i've had good service from them (gnoman), too, but never saw the tiny staples :)
and very nice art direction, too!

[bunrab.livejournal.com]

widdwe teeny trilobites!!

Pill bugs and pansies

[(Anonymous)]

My pretty bed of pansies has become infested with pill bugs. They are eating the plants and flowers, even marigolds, right down to the roots, and I thought nobody liked to eat marigolds! Does anyone have any clue how to discourage pill bugs from inhabiting an area without killing other living creatures? Yes, I know, that's the gazillion dollar question! Diatomatious earth is supposed to pierce their shells and cause them to dehydrate. Someone told me to plant garlic, which they dislike. Someone told me to put down a piece of cardboard in the evening and scoop up the critters gathering underneath in the morning and discard. Any more clever ideas that won't kill frogs, etc? Thanks!

Re: Pill bugs and pansies

[(Anonymous)]

I'm trying to figure this out, too. Someone used dog hair, so this morning I put cat hair around my remaining bean seedling. Another website talked about mulching with a dry material like straw or alfalfa hay ... but it's got to be dry b/c these little crustaceans love soggy.

you do iz besz

[(Anonymous)]

Hi

Looks good! Very useful, good stuff. Good resources here. Thanks much!

G'night

Thanks much!

[(Anonymous)]

Hello

Looks good! Very useful, good stuff. Good resources here. Thanks much!


G'night

Thanks much!

[(Anonymous)]

Hello

Looks good! Very useful, good stuff. Good resources here. Thanks much!


Bye

[drhoz.livejournal.com]

piggy-wigs!

[drhoz.livejournal.com]

also known as slaters

Roly poly's

[(Anonymous)]

I have these ugly critters and they are destroying my flower garden. How do I get rid of them. HELP! PLEASE! I live on Vancouver Island so it is always pretty wet here.

Re: Roly poly's

[urbpan.livejournal.com]

I'd recommend going to your garden shop to get some diatomaceous earth. I'm not sure how well it works on isopods, but it's non-toxic (it works mechanically, as an abrasive), and since they crawl through the soil it shouldn't affect beneficial flying insects.

Re: Roly poly's

[oracle-net.livejournal.com]

The houses in my neighborhood all have flower beds up against the front of the houses and these things live in the soil and mulch. They come in under my front door and from any other crack or gap in the masonry or doors that they can find. I know they're coming in from outside because the flower beds are loaded with these bugs and I've seen them sneak through the crack under the front door. It's annoying enough that I have to sweep up piles and piles of these ugly little things every day, but they are now attracting woodlouse spiders. Any suggestions apppreciated.

Re: Roly poly's

[urbpan.livejournal.com]

You either have to fix the gaps they are getting through (difficult and costly, but the only effective solution) or change the habitat just outside the door. You could also lay a perimeter of glueboards where the woodlice are getting in, but you'll have to change them out occasionally, and it won't solve the problem.

[(Anonymous)]

in ireland we call them 'slaters' [presumably because they look like they're made of slate]

[deponti.livejournal.com]

Wow...didn't know such interesting facts about these "lil critters"....thank you!