A female roach produces one egg sac at a time but could tally ten or more over her lifetime. You'll know you've found a pregnant roach if it appears to have a pill-shaped protrusion sticking out like a fat, ribbed tail.
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 female will carry an egg case for a few days before placing it in a safe location.
German Cockroach
Each egg case holds about 30 to 40 eggs. Females carry the egg case until it is ready for hatching. To ensure the safety of hatchlings, German cockroaches hide before dropping the egg case. These roaches have a gestation period averaging 28 days.
The lifespan of a cockroach is usually one year, and in any female roach's lifetime, she can produce anywhere between 200 to 300 offspring or 6 generations a year. The number of eggs a single cockroach can produce will vary from species to species.
How many roaches in an egg? Each individual egg within an ootheca contains a single developing cockroach nymph. German cockroach eggs for example, can produce as many as 48 baby cockroaches. Even though they don't live very long (between 160 and 450 days, depending on species), they can leave behind a lot of offspring.
You'll know you've found a pregnant roach if it appears to have a pill-shaped protrusion sticking out like a fat, ribbed tail. This extends further as more eggs develop inside it. The “pregnant” female carries her egg case for about 1 month until the eggs are ready to hatch.
Vinegar is a natural household ingredient that can repel and kill cockroaches. Fill a spray bottle with equal parts vinegar and water, and then spray it directly onto the roaches when spotted. The strong odour and acidity of vinegar can be effective in eliminating them instantly.
How Long Do Cockroaches Live? All cockroaches go through three stages of life: egg, nymph, and adult. While these insects usually live about 6 to 15 months, the cockroach lifespan varies based on species, moisture, and temperature in each of these phases.
In that scenario, you can buy what are called desiccant dusts—like diatomaceous earth, a non-toxic substance you can find on Amazon—and that will dehydrate the eggs, thereby killing them.
Roaches produce an egg sac called an ootheca. An ootheca contains many eggs and is encased with a protein substance that will harden into a sturdy, protective casing. This casing is typically shaped like an inflated, curved bean capsule and is usually anywhere from red to dark brown and sometimes even black in color.
Australian Cockroach
The ootheca is dark brown in colour and can be up to 11mm long. The Australian cockroach drops the ootheca in sheltered areas of your home, close to food sources. The female hides the egg casings in holes and tight crevices. This makes them hard to find and treat.
Cockroaches are omnivores that eat plants and meat. They have been recorded to eat human flesh of both the living and the dead, although they are more likely to take a bite of fingernails, eyelashes, feet and hands. The bites may cause irritation, lesions and swelling. Some have suffered from minor wound infections.
Squishing a cockroach releases it's eggs: Fake
As it sits, the protein substance surrounding the egg case hardens, protecting the eggs inside. One ootheca can have anywhere from 10-50 eggs inside, depending on the species.
The Lifecycle of the American Cockroach
Additionally, the female can store sperm, meaning she only needs to mate once to lay multiple egg cases. Females will lay anywhere from 6 to 14 egg capsules in their lifetime.
Cockroaches prefer nesting in areas that are more likely to absorb their strong odor — places where you store paper, cardboard or wood. Thus, if you store your clothes in a wooden dresser, cockroaches will be more likely to lay eggs in your clothes.
Fun Facts: Some Female Cockroaches only Mate Once and Stay Pregnant for Life! Can you imagine being pregnant for life! The average lifespan of an adult cockroach is about 1 year depending on the species. They have 3 cycles from egg to multiple nymph stages to adult.
Bleach's Effect on Roaches
Taking a deep drink of household bleach would kill anything, roaches included. But the same strong odor that keeps people from taking a swig of bleach repels roaches as well. So though it could work, in reality, it will not. It is very difficult to kill an entire roach infestation yourself.
The best home remedy to get rid of roaches is boric acid. To create the boric mix, combine it in equal amounts with flour and sugar to make 'dough balls', each around an inch across. Put the dough balls where you've seen the cockroaches; they will feed on them and be killed.
To start, vacuum up cockroach egg capsules, young cockroaches and adults, when possible. Use a vacuum cleaner with a high-efficiency particulate air (HEPA) filter to help reduce cockroach debris that can become airborne and could trigger asthma attacks and other health concerns in people who are allergic to roaches.
When cockroaches die, they release a chemical known as oleic acid. This chemical has a moldy smell that other living cockroaches are attracted to. The live roaches can smell this odor from a long distance.
Australian cockroach (Periplaneta australasiae)
Females produce up to 20 egg cases, each containing up to 24 eggs. Development takes 6-12 months and adults live for 4-8 months.
In a total vacuum, most cockroaches will be dead in minutes (though some can go for as long as 45 minutes).
Smells that roaches hate: a quickfire summary
Oregano, rosemary, mint, eucalyptus, lemongrass and catnip are great herby options. Citrus oils work brilliantly too. And surprisingly, lower concentrations – 2.5 parts per hundred – seem to work best as deterrents. Just don't bother with lavender.
Citronella
Citronella not only works great for repelling mosquitos but also cockroaches. While the candles don't work well against roaches, you can use citronella oil as a deterrent. You can mix it with water and use it as a spray or simply wipe down areas with the diluted mixture.
It's instinctive: you see a cockroach and you crush it. Or you run away. However, entomologists advise against doing the former, because cockroaches can support 900 times their weight. Lightly stepping on the insect or swatting it with a newspaper is not the best plan.