Answer: Sowbugs and pillbugs are scavengers and feed mainly on decaying organic matter. They occasionally feed on young plants but the damage inflicted is seldom significant. Sowbugs and pillbugs thrive only in areas of high moisture, and tend to remain hidden under objects during the day. Around buildings they are common under mulch, compost, boards, stones, flower pots, and other items resting on damp ground. Another frequent hiding place is behind the grass edge adjoining sidewalks and foundations.
Various insecticides sold in hardware/lawn and garden shops are effective, including Sevin, Dursban, diazinon, and permethrin (Spectracide Bug Stop). Or, you can trap and dispose of them by laying tubes of moistened newspaper on the soil at night (the sowbugs will crawl in to hide), then picking them up in the morning, folding over the ends so they can't escape, and tossing them into the trash. With a large population you may have to make repeated attempts before you can capture them all.
Best wishes with your garden!
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