The cockroach life cycle starts at the egg stage. A female cockroach produces eggs inside a protected, purse-shaped capsule known as ootheca. The eggs are laid into individual compartments inside the egg capsule where they eventually develop. The number of eggs produced per egg capsule depends on the species of the cockroach; it can range from 10 to 60. Likewise, the number of egg capsules produced by a female in her lifetime depends on the species; it may range from 5 to 30. Some cockroaches such as the German cockroach carry the egg capsules around for much of the developmental process, dropping them off in safe, hidden locations just a few hours before the eggs hatch. While others like the American cockroach drop the egg capsule a few hours or days after its formation.

What Do Cockroach Eggs Look Like?

Contrary to what some may believe, cockroach egg cases can be seen with the naked eye. The egg cases are usually reddish-brown to dark-brown in colour and range from 5 to 13 mm long depending on the type of cockroach. Egg capsules typically may go unnoticed because they are deposited and glued in hidden to semi-hidden locations which are not readily visible or hard to reach, such as behind picture frames or under furniture. Finding a visible egg case is a sure sign of infestation in the home.

German Cockroach

The German cockroach is the most important and common cockroach in Canada. A concerning pest, the German cockroach reproduces quickly and efficiently. The female carries around the developing eggs inside the egg capsule and deposits the capsule right before eggs hatch. After depositing an egg capsule, the female can begin producing more eggs in a matter of weeks. As many as 50 nymphs may hatch from a single ootheca. Female German cockroaches usually produce between 4 and 8 egg capsules in a lifetime. Because German cockroaches produce multiple egg capsules containing large numbers of eggs, populations can boom in a relatively short amount of time. A typical German cockroach infestation population will contain about 75% nymphs.

What Do Baby Cockroaches Look Like?

Like other insects, cockroach species found in Canada reach adulthood by undergoing molting processes at each step of a multistage life cycle. Baby cockroaches known as nymphs hatch from eggs after an incubation period of about 20 to 60 days, depending on species and environmental conditions. The nymphs are miniature versions of adults, except they lack wings and differ in color from adult cockroaches, often lighter in colour. The German cockroach, for instance, which ranks as the most important and common species in Canada, produces nymphs that are darker in color than adults and feature lighter-colored longitudinal streaks running down the backs of the baby insects. Baby cockroaches develop wings and grow into adults by completing a series of molts. The transitional period of time in between each molt is called an instar. Baby cockroaches typically go through six or seven instars and become fully grown adults within 40 to 160 days, depending species and on the temperature of the surrounding environment.