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Past Articles Library | Organic Pest Control | Sowbugs Pillbugs

SOWBUGS / PILLBUGS

Sowbugs, also known as pillbugs or woodlice, feed mostly on old, and decaying plant material, but they can go after young seedlings causing severe damage. They can also occasionally enter homes in damp areas such as basements, first floor levels, garages, and pools.

DESCRIPTION

Adults are gray or brown crustaceans about 1/4 to 5/8 inch (6-15 mm) long, with numerous segments of what look like jointed armor. They have seven pairs of short legs that are not very visible. Pillbugs will curl up into a ball if bothered. Sowbug nymphs look like small adults.

LIFE CYCLE

Females carry eggs and young nymphs from 7 to 200, in a pouch for several weeks. Nymphs and adults have gills which need constant moisture so they prefer moist conditions and don't live long on dry surfaces. In early spring, with rain, they emerge from their overwintering areas all at the same time, making it seem as though a population explosion as occured. Sowbugs can live up to 3 years.

PLANTS MOST AFFECTED

Seedlings of many plants.

DAMAGE

Sowbugs and pillbugs tend to feed on decaying organic matter and cause little to no damage on established healthy plants. They can, however, when their numbers are high enough, severely damage seedlings by chewing on leaves and fine roots.

MEANS OF CONTROL

Prevention:

Since sowbugs and pillbugs require moisture to survive, keep normally wet areas dry by draining or removing moisture.

Remove trash, leaf litter, boards, and other debris around houses and garden beds to remove hiding and overwintering sites and to remove moist areas where they thrive.

Control:

Sprinkle diatomaceous earth around seedlings.

Trap pillbugs under stones, boards, or cabbage leaves and destroy them every morning.

Set out traps made from paper painted with sticky trap glue, then folded like a tent, with the glue-side down. Replace as needed.