There are three stages in the Cockroach life cycle: egg, nymph, and adult. Roach eggs develop in a casing called the ootheca. When a female roach is carrying an ootheca she is said to be ‘gravid’. The egg cases are so distinctive in shape and size. One ootheca can contain up to 50 eggs. Some cockroaches glue the ootheca to a hard surface so it can’t be removed until the eggs inside it hatch. German cockroach is unique in that she carries the ootheca for nearly the entire incubation period. Once hatched all roaches develop with gradual metamorphosis. Development from eggs to adults takes 2-4 months.
- The German cockroach’s egg cases are light brown in color and typically measure about 1/3 inch (8–10mm) in length.
- The American cockroach’s ootheca is mahogany brown in color and measures approximately 1/3-inch (8–10mm) in length.
- The brown-banded cockroach’s ootheca is yellowish or reddish-brown in color and averages 1/4-inch in length.