Thursday, June 25, 2009

When pillbugs come marching in

The heat is on across the Rolling Plains, and we two-legged critters are not the only creatures affected by these triple-digit days. If you live with domestic animals, dear reader, please insure that they have access to shade, to whatever breeze may blow and to fresh water!

Critters of the wild suffer as well through the dog days of summer. Most of us who feed wild birds also put out fresh water, typically several times a day, for the birds. In fact, if you want to attract birds to your yard, water attracts far more birds than food, no matter what time of year.

And then there are
Armadillidium vulgare, a.k.a. pillbugs, sowbugs, roly polies, woodlice and even Armadillo bugs. Our entire 15 acres down at the nature center are crawling with them, and just this past week or so since the outside temperatures have been cranking up, these little isopods have been invading our air-conditioned buildings in impressive numbers.

Yes, I said "isopods", for the common pillbug is not a bug at all. Like I tell the kids, put one in your hand on its back, and wait for it to open up from its tight ball posture. Look close and you will see seven pairs of legs! By my 3rd-grade arithmetic that's 14 legs in all; and the last time I checked, insects still have but six.

In fact, the lowly pillbug as a group is the most successful of all land-dwelling crustaceans, numbering some 5,000 species. As crustaceans they are kin to shrimp, crawfish, lobsters and the like, and therein lies a connection as to why these guys come marching into all manner of man-made structures each summer. They, too, are looking for water!

Isopods go back at least 300 million years to the primordial seas of the Pennsylvanian epoch. Today their breathing organs remain more like gills than lungs, so they must have a moist habitat in order to survive. Therefore, these little guys are not invading your house to get to your house plants! They just need a cool, damp place to breathe.

Okay, IF they happen to find your house plants, they are not above snacking on them. But for the most part pillbugs and other kinds of woodlice dine on organic debris, helping to breakdown plant material into soil. As such they pose positively no threat to people nor any other animals, with the possible exception of nature center field guides.

You see, once a kid on a field tour discovers the roly polies, it's nigh on to impossible for the guide to get the groups' attention focused anywhere else!

1 comment:

Penny Miller said...

Jim,

Pill bugs have been one of my favorite critters since childhood. Thanks for writing about these interesting animals.

Penny