I was visiting the insect collection in the Department of Entomology at the University of Arizona in Tucson yesterday, when in the process of moving a cart to get to a cabinet, I discovered a cockroach, belly-up on the floor. I could tell it was a brown-banded roach even before I turned it over. I had seen another dead one here before (before I had a camera). The neat thing about this one was that it was a male.
Oddly, I have never seen a living adult male of this species. Then again, until I saw live ones at the University of Massachusetts, I had not seen a living example of either gender. I suspect they are less populous than other “domestic” roaches, and maybe more secretive, too.
In any event, Supella longipalpa is an outstanding example of sexual dimorphism in the order Blattodea. While the females are broad-bodied with shortened forewings (called tegmena), males are more slender, with long tegmena and fully-functional hindwings as well.
Other cockroach species have even more dramatic differences between the sexes, males being fully winged and females totally wingless. The sand roaches in the genus Arenivaga come to mind. They occur here in the Arizona outdoors, so maybe I’ll eventually be able to share their story here on my blog as well. For now, though, I can close the book on the brown-bandeds.