Re: How isopods differ from insects

Hi Zhanna,

You asked how isopods differ from insects. The most obvious way that these animals differ is in the number of legs. Insects have three pairs of legs, and almost all have wings as well. Here's a diagram of an insect that shows the legs and wings:

Isopods, on the other hand, have seven pairs of legs. The critters that are commonly called "pill bugs" or "sow bugs" are isopods. I imagine that you have these animals where you live. The next time you come across one, pick it up and let it unroll in your hand. I promise it won't bite you! If you look carefully, you should be able to count the seven pairs of legs. Here's a diagram of an isopod to compare your pill bug to:

Insects and isopods belong to different subgroups within the Phylum Arthropoda. Isopods are members of the Subphylum Crustacea, and are more closely related to crabs and lobsters than to insects, which are in the Subphylum Uniramia. The following webpages will help you find other differences between isopods and insects:

http://www.wcsz.org.zm/ useful_insect_stuff.htm
http://insected.arizona.edu/isoinfo.htm

I hope this answers your question and prompts you to investigate these interesting creatures on your own!

Allison J. Gong
MAD Scientist