[Pest Profile] Pillbugs/Sowbugs

Class/Order: Crustacea/Isopoda

Scientific Names: Armadillidum vulgare (Latreille) — Common Pillbug

Porcellio laevis Koch — Dooryard Sowbug

Porcellio scaber (Latreille)

Description

Pillbugs and sowbugs are dark gray, 1/4- to 5/8-inch long, oval crustaceans that are humpbacked and have seven pairs of similar legs. Pillbugs can be distinguished from sowbugs because pillbugs are able to roll up into a ball when alarmed and lack the two prominent tail-like appendages that characterize sowbugs.

Biology

Female pillbugs and sowbugs carry their eggs in a "brood pouch" where the young hatch in about 45 days. The young molt every one to two weeks until they become adults. Adults live about two years.

Habits

Pillbugs and sowbugs usually are found in moist situations where they feed on organic matter. They are commonly found outdoors under stones, boards and piles of plant material. Pillbugs and sowbugs invade basements, crawlspaces and sometimes other parts of structures that have higher-than-normal moisture. They cause no damage but are considered a nuisance. Unless disturbed, they are usually active only at night.

Control

Pillbugs and sowbugs are best controlled by eliminating the moist environment that initially attracts them. Entry into buildings should be prevented by sealing and caulking gaps around siding, windows, doors, pipes, wires, etc. Large numbers of pillbugs and sowbugs that successfully invade homes are easily controlled by vacuuming them up and discarding the collected material. Microencapsulated and wettable powder products are the most effective formulations in the moist habitats preferred by sowbugs and pillbugs. These products should be applied around the perimeter of the structure, into harborage sites and around potential entry points. Application of these products indoors may be necessary and can be supplemented by the use of dusts in drier areas.