Claire Stuart, Bug Lady

Claire Stuart, Bug Lady

Since I have often said that I think rats and roaches will inherit Earth if humans continue to ruin it, here’s a little info about the lives of roaches.

Cockroaches were once lumped into the same insect order as grasshoppers, crickets, mantids and stick insects. However, they have been given their own order, Blattodea. Interestingly, just recently, termites were declared to be related to roaches and moved into that order.

Cockroaches are extremely ancient. Roach-like insects were present over 300 million years ago, long before dinosaurs. Modern roaches developed somewhere around 120-130 million years ago and have been around, virtually unchanged, since then.

There are over 4,500 species of roaches worldwide, living on every continent but Antarctica, but only a few affect humans. In North America, only four species are considered pests: German roach (Blatella germanica), American roach (Periplaneta Americana), brown-banded roach (Supella longipalpa), and oriental roach (Blatta orientalis). All are scavengers and eat just about anything, especially starches, sweets, grease and meat products. Some even eat book bindings and wallpaper paste.

German roaches (about Ω inch long) are the commonest home pests because they like a moist, warm environment and their size allows them to get through small spaces. Brown-banded are similar but even a little smaller. American roaches are larger (about 1-1 Ω inch) and are commoner in industrial buildings. They all have long wings but can’t fly, and all of them quickly scurry off to avoid light.

Oriental roaches are often called water bugs or black beetles. They prefer dark, moist places such as sewers, drains and damp basements. They can travel through sewer pipes and come up in floor drains. They are actually commoner in moist outdoor environments than in homes. The female is wingless and the male has wings that only cover about half of his abdomen. They are an inch or more long and very slow moving.

All roaches develop as nymphs that resemble small adults, with wings appearing at adulthood. Eggs are laid inside of an egg case called an ootheca. It is leathery and shiny and resembles a tiny purse.

German roaches carry the ootheca (holding 30-40 eggs) attached to the abdomen for weeks until eggs hatch, and the female can produce four to eight oothecae in her lifetime of about 20-30 weeks.

American and oriental roaches also produce oothecae, but both of these species only carry them for a few days, and then glue them to a hidden surface. They are often glued to undersides of furniture and drawers — something to look for if you buy used furniture! Adult females can live a year and will produce seven to 10 oothecae.

A fairly common roach in wooded areas is the Pennsylvania wood cockroach (Parcoblatta pennsylvanica). It is not a pest of homes but can accidentally get in, especially in the mating season. It is nearly identical to the American roach, but it usually stays in rotting stumps or behind decaying bark where it eats decaying wood material.

The biggest difference between wood roaches and the other roaches is that male wood roaches can fly, and they are not afraid of light. Females have short, nonfunctional wings. In mating season, males fly in search of females and sometimes land on the sides of houses in large numbers.

It’s been said that roaches can survive a nuclear explosion because they were found alive after atomic bombs were dropped on Japan. It’s true, to a degree. Researchers exposed German roaches to radiation that could kill a person in 10 minutes (1,000 rads of cobalt 60) and half were still alive after a month. Others were tested with 10,000 rads and 10 percent survived. However, none survived when exposed to 100,000 rads.

Roaches don’t directly cause diseases, but they can transmit bacteria by walking through or feeding on contaminated surfaces and then walking or defecating on our food.

Send your insect questions to Claire Stuart by e-mail at or write her (with self-addressed stamped envelope) in care of Living Section, The Journal, 207 W. King St., Martinsburg, WV 25401.