Roly-poly, pillbug, doodlebug, or sowbug, whatever you call them, the more you know about these creatures, the weirder they get.
First, they are not really bugs. They are a type of crustacean, called a woodlouse. Our garden-variety woodlice are in the Armadillidium genus, making them cousins to armadillos! Like armadillos, pillbugs can roll up into a ball, and often do, when disturbed. Other woodlice cannot do this.
Even stranger than being related to armadillos, female woodlice carry fertilized eggs in a marsupial pouch, like a kangaroo! They can also reproduce asexually. If that weren’t enough, sowbugs breathe through trachea-like lungs in their feet! These fascinating creatures can live for several years, producing two or three generations each year. Each brood can include 30 to 80 offspring. In particularly rainy years, pillbugs can be a problem in the garden.
Woodlice prefer cool, dark, moist places - under planters, bricks, hoses, dense vegetation, whatever they can find. Having evolved from sea-going crustaceans, such as lobster and crab, water is critical to their survival. [Note: don’t eat them. Wikipedia says they taste like “strong urine”. I don’t know how they found out and I am certainly not going to try it myself!]
Dead plant material is a woodlouse’s favorite food. This makes them very helpful in compost piles and soil aeration. They also eat stinkbug eggs! Unfortunately, they frequently eat ripe strawberries, lettuces and cabbages, and plants with fruits that lay on the ground, such as squash and melons. These pests can chew tender seedlings down to the ground in a single feeding! Most of this feeding is done in the evening and at night. Other favorite foods of pillbugs include zinnias, blue lobelia, verbena, alyssum, pansies, and cardinal flower.
While pesticides can be effective, there are better ways of controlling these pests. The best way to take advantage of the benefits, without the risks, is to reduce dark, moist hiding places, and to keep mulch and other dead plant material away from seedlings, until they are large enough to survive being gnawed by a woodlouse.
You can grow a surprising amount of food in your own yard. Ask me how!