Species

Sow bugs, Porcellio Scaber, belong to the class Crustacea and the order Isopoda.

Host/Site

Sow bugs require a moist environments. They are found outdoors under mulch and stones, as well as within soil, compost, and flowerpots. They are active at night and hide in the dark during the day.

In the home, sow bugs rarely live for more than three days, but are found in laundry rooms, exposed pipes, crawl spaces, and damp basements. They enter homes through baseboards, door thresholds, cracks in concrete or foundations, and any unsealed entry point into the house.

Sow bugs help recycle nutrients into the soil and feed on decaying organic matter. They should not be considered a pest, even though they sometimes eat saplings and young plants.

Identification

Indicators
Bite marks in plants do not necessarily indicate sow bug problems; they are often blamed for damage that they don't do. Be sure to look for other pests, e.g. snails and slugs, to discern which is doing the most damage.

Life Cycle

Sow bugs breed mainly in the spring. Females carry the fertilized eggs in a pouch underneath their body where they will remain for an additional two months after they have hatched. Sow bugs reach adulthood within a year and can live for up to three years.

Natural Enemies

Natural predators include frogs, toads, newts, toads, spiders, and small mammals

Monitoring

Since sow bugs are often found underground it can be difficult to monitor for their presence. Any damage caused to young plants is normally not significant enough to need a control. There may be greater need for monitoring indoors. Regularly inspect moist, damp areas of your home such as crawlspaces, basements for their presence.

Action Threshold

Be hesitant to eliminate sow bugs from the garden. They are valuable in removing decaying plant matter and help with decomposition. Only if they pose a direct threat to seedlings or crops should they be controlled.

Physical/Mechanical Controls

The most foundational way to control sowbugs is to minimize moisture within and around the house. Be sure to divert water from the foundation, and clear and maintain gutters and drainages.

Dehumidify rooms, and make sure crawl spaces and attics are well ventilated.

Seal all cracks and openings with caulk, install tight-fitting door sweeps at the bases of all exterior entryways.

Outside the home, clear away extraneous debris and vegetation around the perimeter of the foundation. Leave a border of bare soil next to the foundation, creating an inhabitable space for insects between the yard and the home.

Consider watering early in the day, so the soil dries out by evening. Agitate the soil surface—it speeds drying and works plant materials deeper into the soil, making it more difficult for sow bugs. Do not over-water soil near the house.

Biological Controls

Diatomaceous earth dust is an all-natural organic spray that deters insects from the region sprayed. Apply it around saplings in order to prevent sowbugs and other pests from feeding.

Chemical Controls

Not recommended. If insecticides are deemed necessary, use a low-toxic substance, such as insecticidal soap. Apply it to the perimeter of the household or to inhabited regions of the garden.

References

Hahn, Jeffrey, and Mark E. Ascerno. "Sowbugs, Millipedes, and Centipedes in the Home." University of Minnesota Extension. 2003. 6 Nov. 2008. <http://www. extension.umn.edu/distribution/housingandclothing/DK1023.html>

Lyon, William F. "Sowbugs and Pillbugs." Ohio State University Extended Fact Sheet. Entomology. 6 Nov. 2008. <http://ohioline.osu.edu/hyg-fact/2000/2072.html>

Potter, Michael F. "Sowbugs and Pillbugs." University of Kentucky Entomology. 1998. University Department of Agriculture. 6 Nov. 2008. <http://www.ca.uky.edu/entomology/ entfacts/ef439.asp>

"Sowbugs, Pillbugs." Agri-Life Extension. Texas A&M System. 6 Nov. 2008.
<http://insects.tamu.edu/fieldguide/cimg377.html>.