Sowbugs and Pillbugs

Sowbug/Pillbug Feeding on Watermelon (© 2009 Caroline Homer)
Sowbug/Pillbug Feeding on Watermelon (© 2009 Caroline Homer)

Pill Bug
Pill Bug (Joseph Berger, Bugwood.org)

Description

Adult: About ¼ to ½ inch long, with a rounded upper surface and flat lower surface. They are dark gray in color with armor-like body segments. Sowbugs and pillbugs are not insects, but are soil dwelling crustaceans. They have 7 pairs of legs, prominent antennae, and two tail-like appendages.
Egg: Up to 200 eggs are carried in a pouch under the female body.
Young: Young sowbugs and pillbugs look like adults but are paler in color and smaller.

Life History

Eggs hatch into young sowbugs and pillbugs, and remain in the pouch up to 2 months after hatching. It requires about 1 year for young sowbugs and pillbugs to develop into adults. Adults breed mainly in the spring and may live up to 3 years. As many as three broods per year are possible.

Damage

Sowbugs and pillbugs feed on melon rinds (especially cantaloupe) when fruits rest on soils with high levels of organic matter on the surface. They occasionally damage roots, seedlings, foliage and fruit that contact the soil.

Management

Cultural

  • Minimize soil moisture. Reduce soil moisture as fruits ripen to deter the attraction of sowbugs and pillbugs to the area. Sowbugs and pillbugs rely on moist soil to survive and will not live in soil that is too dry to support them.
  • Remove debris such as trash, plant debris, or wood. Debris encourages soil moisture and protected sites that will attract sowbugs and pillbugs.
  • Mulches. Place straw, plastic, cardboard, landscape fabric, carpet, or other types of mulches under cantaloupes and other fruits and vegetables that tend to sit on or contact the soil as they ripen. These mulches will create a barrier between the ripening fruits and the soil where the sowbugs and pillbugs live.

Chemical

Generally cultural management practices, such as mulches and soil moisture management are the most effective in preventing sowbugs and pillbugs from becoming a problem.