When you think of cockroaches, “cute” isn’t usually the first word that comes to mind. Yet that is how Therea petiveriana, or the Domino cockroach, is often described. The Domino cockroach hails from the scrub forests of Southern India, and spends most of the day burying itself below the leaf litter, emerging at dusk and dawn to feed on decaying organic matter.
Domino cockroaches are an excellent example of Batesian mimicry. The spotted pattern on their tegmina, or wing covers, closely resembles the pattern on Anthia sexguttata (seen on the right). A. sexguttata is a ground beetle from the same region that is capable of spraying concentrated formic acid at predators, causing irritation and occasionally blindness. The Domino roach has no such defense, and cannot bite or sting, so the next best option? Look like someone who does. The spots are their way of saying, “Do you really want to take your chances with me?”
Now let’s play a game; as Bug Wrangler, it’s one I play on a daily basis. It’s called “Poop, or Not Poop?” The weird brown mass seen in the picture above doesn’t exactly look like poop, but not quite like an egg. That’s because it’s neither. It’s an ootheca, or egg case. The number of eggs per ootheca can vary from 1-16, depending on the age of the female. When the nymphs hatch out, they bury themselves in the substrate and are rarely seen on the surface again until they emerge as adults. Unless they’re like this chunky juvenile below, who spends most of his time buried in the cat food we provide as a protein supplement.
