Chapter 3: Cockroach Life Cycle
As you probably would expect, cockroach babies aren’t exactly cute and cuddly. It still helps to know where you can find them, especially since a female American cockroach will hatch about 150 nymphs in her lifetime, and German cockroaches can produce thousands of cockroaches a year.
In this chapter, we’ll look at the different cockroach stages and where a pregnant cockroach may wind up hiding her eggs. If you found cockroach babies hanging out in your home or business, don’t hesitate to give us a call at Pestech Pest Solutions.
Life Cycle of a Cockroach
To get an infestation under control, it helps to understand the cockroach life cycle and breeding habits. That way, you’ll know how to identify cockroach eggs and take action before an infestation spreads.
A cockroach has three life stages — the egg, the nymph stage and adulthood. We’ll look at each stage for common household cockroaches.
Here’s a little bit about the reproductive habits of problematic cockroaches. As you’ll see, German cockroaches may carry almost three times as many eggs as other species:
- American cockroach: Female American cockroaches lay eggs in a hard case called an ootheca. About one week after mating, the female produces an ootheca. On average, females produce one ootheca each month for ten months, laying an average of around 16 eggs per case. The pregnant cockroach will carry an egg case for a few days before placing it in a safe location.
- German cockroach: The German cockroach produces more eggs per ootheca than any other pest cockroach, carrying 30 to 40 eggs in each case. Female German cockroaches keep the ootheca on their body until the eggs are ready to hatch. To make sure her babies are kept safe, the cockroach will hide before dropping the egg case. The average gestation period for a German cockroach is 28 days.
- Brown-banded cockroach: Brown-banded cockroaches carry about 16 eggs per ootheca. The female cockroach will keep the ootheca with her for about a day or two and then adhere the egg case to a piece of furniture, wall, cardboard or another rough surface. The eggs start to hatch in about 50 days.
- Oriental cockroach: Oriental cockroaches carry an average of 16 eggs per ootheca. Female oriental cockroaches drop egg cases in warm sheltered areas with abundant food. The incubation period lasts around two months.
The cockroach nymph stage begins when the egg hatches and lasts until the cockroach baby reaches adulthood. Here’s what to expect with each type of nymph:
- American cockroach: American cockroach nymphs look similar to adults, except they don’t yet have wings and are smaller in size. An American cockroach changes six to 14 times before it’s an adult. It takes about 600 days for an American cockroach to reach adulthood from the egg.
- German cockroach: German cockroach nymphs are darker than adults and have a tan stripe on the back. These tiny creatures begin to search for food immediately and grow fast in ideal conditions. They’ll shed their skin, or molt, about six times as nymphs. After the final molt, they emerge with ready-to-use wings. It takes about 103 days for a nymph to grow into an adult. Once they grow up, they are able to reproduce.
- Brown-banded cockroach: Brown-banded nymphs molt up to eight times over the course of five to six months. After their last molt, they are ready to reproduce. It can take up to 276 days for a brown-banded cockroach to mature into an adult from the egg. Male adults can easily fly if they feel threatened.
- Oriental cockroach: Oriental cockroach nymphs are most active in the spring and summer. An oriental cockroach will grow into an adult anywhere from 300 to 800 days from the egg.
It may be a relief to learn that adult cockroaches don’t live for many years. However, they can contribute to their population substantially throughout their lifetimes. Here’s how long each type of cockroach typically lives for and a little bit about their adult life:
- American cockroach: American cockroaches can live for up to a year. Cold temperatures in the north keep them from reproducing rapidly, but their populations can grow to immense numbers if the conditions are right. American cockroaches can be found easily in city sewers and commercial buildings, and they’ll wander into homes to look for food or escape uncomfortable weather conditions. They can live in the same building as German cockroaches.
- German cockroach: A German cockroach completes a life cycle in about three months. They will repeatedly reproduce during that time, producing a new generation around every 60 days. This can lead to thousands of ready-to-mate cockroaches, and ultimately, a population of millions within a year.
- Brown-banded cockroach: Unlike German cockroaches, brown-banded cockroaches won’t generate as large of a population. A female may produce around 250 offspring, but since it takes longer for nymphs to mature, it’s not as easy to grow a big population quickly. In warm temperatures, brown-banded cockroaches can live for about 80 days.
- Oriental cockroach: Unlike other common cockroaches, Oriental cockroaches can live outside in the northern United States. When it’s hot and dry out, they might come inside to cool down in basements, crawlspaces and bathrooms. While outside, they prefer spending their time near organic matter, such as underneath trash cans or in the mulch. An adult oriental cockroach may live anywhere from 34 to 180 days.
How Long Do Cockroaches Live?
Common pest cockroaches, depending on the species and sex, may live anywhere from a month to over a year. For example, German cockroaches live for about 100 days, but female German cockroaches may live for more than 200 days, and American cockroaches can survive for up to a year.
Are Cockroach Eggs Visible?
An ootheca is usually large enough to be seen. However, the individual eggs are hidden inside. For example, an American cockroach egg case is about 8 millimeters long. When deposited, the egg case is brown and turns black within a day or two.
Where Do Cockroaches Lay Eggs?
The two most common pest cockroaches –– the German cockroach and the American cockroach –– have slightly different egg-laying styles. German cockroaches carry their eggs with them until they are ready to hatch. When it’s time for hatching, the female cockroach will drop the ootheca wherever she is.
American cockroaches carry their egg case for a few days before depositing it in a corner or crevice near a food source. The cockroach may stick the ootheca to a cupboard or another surface using saliva and debris.
Do Cockroach Babies Fly?
Baby cockroaches are wingless, so they can’t fly. Once they are fully grown, they may or may not have wings