Source: Iowa State University
Isopods have become a new early-season soybean pest in the Midwest and have multiple common names, including woodlice, pillbugs, sowbugs and roly-polies.
Although isopods have three major body regions (head, thorax and abdomen) like insects, it is very difficult to distinguish the regions because of the armor-like plates on the back. They have two pair of antennae (usually only one pair is obvious), seven pairs of legs and simple eyes. Immatures look like adults except are smaller in size and proportion. Most isopods are grey or black and some have dark markings on the back. Adults are oval in shape and three-eighths inch long. In general, the back is convex and the underside is flat or concave.