Sowbugs and pillbugs
(sometimes called "woodlice" or "rolypolies") belong to the arthropod
class Crustacea and are closely related to the shrimps, crabs, lobsters,
crayfish, and barnacles. The sowbugs and pillbugs (order Isopoda) are
the only members of this group that are terrestrial and do not live
in the water. The sowbug (Porcellio spp.) has seven pairs of legs and
measures about 13 mm (1/2 inch) in length. The body is grayish or brownish
and composed of segmented, overlapping plates. There are two pairs of
antennae (only one pair readily visible), well-developed eyes, and a
group of short appendages at the tip of the abdomen. Sowbugs, Porcellio
sp. The pillbug (Armadillidium sp.) is similar to the sowbug, but is
generally larger (15 mm - 2/3 inch), darker (dark slate gray), and has
no appendages at the tip of the abdomen. Pillbugs are capable of rolling
themselves into a neat, circular ball ("pill") for protection; sowbugs
generally prefer to scurry away (at most they can curl into a C-shaped
posture). The biologies of these two isopods are very similar, and they
will be discussed together. Sowbugs and pillbugs are generally found
in leaf piles and compost heaps, in rotting logs, and under stones.
At night they become very active and wander about in search of food.
. Sowbugs and pillbugs overwinter as adults. Mating occurs in the spring
(April to June), and the female carries the eggs in a special brood
"pouch" located on the underside of the body. The eggs mature over a
period of 50 to 90 days and then hatch. The immatures are similar to
the adults, except that they are smaller in size, lighter in color and
sometimes have fewer legs. Generally speaking, it takes a full year
for the immatures to reach adulthood. The adults may live for 2 or 3
years if the environment is favorable.
DAMAGE AND CONCERNS
They may also
be common near buildings, especially where it is dark and damp, and
may be found in basements, crawl spaces, garages, sheds, around wells
and cisterns, and under all types of debris. Their diet consists of
various plant materials, usually moist, decaying vegetation. They are
also known to feed on living plants (garden crops, flowers, and fallen
fruit), and even some animal materials (manure, carrion, and other sowbugs).
Prepared by
the Young Entomologists Society, 6907 West Grand River Ave., Lansing
MI 48906-9131, phone/fax 517-886-0630, e-mail YESbugs@aol.com. Support
minibeast youth education - join Y.E.S. today!
CONTROL
Sowbugs are such
abundant animals in most gardens that there is little chance of any
lasting reduction in their numbers. Where susceptible plants such as
seedlings are being damaged, eliminate protected, damp locations and
decaying plant material. Trap boards or stones can serve as shelters,
from which they can be collected and destroyed during the day.

Aries
Pest Control, Inc.