Re: Why are some cockroaches white??

Dear Kristi,

Thank you for your question about white cockroaches. I believe what you saw was a recently molted cockroach.

All insects shed their exoskeletons several times in order to grow bigger. The process of shedding their exoskeletons is called molting. Just after the old skin is shed, the new skin in many insects is very pale. The insect then pumps up this pale, delicate new exoskeleton to a bigger size for it to harden into place. The hardening, which is referred to as scleratization, may take place over several days for some insects.

This link has a beautiful picture of all the stages of a cockroach. (Well, I think it's beautiful anyway!) The cockroach you saw probably looked like one of these stages, only very, very pale.

A brief description of the molting process in cockroaches can be found here.

Usually an insect that has recently molted will be more shy than at other times, because its exoskeleton is not as protective as it is when fully hardened. Not everyone gets to see a recently molted cockroach, you should feel very lucky! If you have any more questions, please ask us again!


Sincerely,

John Carlson
MAD Entomologist