Pillbugs and sowbugs

About

Not insects but land crustaceans with seven pairs of legs and gray, armored bodies. Pillbugs roll into a ball; sowbugs cannot. Both mostly eat decaying plant matter.

Spotting it

Damage

Now and then they chew seedlings, roots, low leaves and fruit resting on the soil, leaving ragged holes that look like slug damage.

How to find it early

Look under boards, mulch and fruit sitting on damp soil, and check seedlings at night.

When

Spring through fall, especially after long wet spells.

Life cycle

Adults overwinter and breed in spring; females carry eggs in a pouch for up to two months before the young emerge. Young take about a year to mature, there are one or two generations a year in Utah, and adults can live two to five years.

What to do, gentlest first

Start at the top. Sprays are a last step; always read and follow the product label.

1. Dry things out Prevent

   Water less often and early in the day, switch to drip irrigation, and remove decaying debris. Keep mulch and compost back from seedlings.

2. Keep fruit off the soil Barrier

   Use raised beds or plastic mulch, and trellis vines, so strawberries and melons do not rest on damp soil.

3. Usually unnecessary Conventional spray

   Colorado State says controls used for millipedes, such as pyrethroids, also work, but that control is generally not needed.

   Fix moisture first; sprays do little if the damp habitat stays. Follow the label.

Plants it goes after

Cantaloupe (muskmelon), Cucumber, Green beans (snap beans), Lettuce, Strawberry, Watermelon

Pressure by region

Rated low everywhere because they feed mainly on decaying matter; Colorado State says control is generally unnecessary. Hawaii's home-garden pest guide also lists sowbugs (CTAHR).

Ratings come from extension sources where available; some are estimates, as noted above.