How did it get here?
German cockroach is actually a tropical species whose
point of origin may be Southeast Asia. It spread to America
aboard the ships of European immigrants sailing to the
Colonies. Highly mobile and adaptable to new environments,
the species became a household pest worldwide during the
How to spot
German cockroaches are nocturnal and secretive. They
spend most of their time in cracks or crevices in walls,
between cabinets, and under furniture. Signs of cockroaches
include carcasses, body parts, shed skins, empty egg cases
(amber-colored, ribbed cylinders) and fecal smears (dark
Cockroaches live where humans dwell. They prefer warm,
undisturbed areas with high humidity near a source of
water—under sinks, around toilets, and in showers.
They eat human food and also non-food items like soap,
toothpaste, and glue. Small nymphs can live in a crack
as small as 1/32 inch, while adults require one at least
3/16 inch wide.
produce four to eight egg cases, each containing 30 to
40 eggs. They carry the cases until the eggs are within
a day or two of hatching, then deposit the cases in a
protected site. The development from egg to adult varies
with temperature and humidity, but on average it takes
103 days. Three to six generations may be produced per
year. Adults can live 100 to 200 days.
Look-alikes and how to distinguish
• American cockroach (see http://pested.unl.edu/chapter3.htm#cock3e)
• Brown-banded cockroach (see http://pested.unl.edu/chapter3.htm#cock3c)
• Oriental cockroach (see http://pested.unl.edu/chapter3.htm#cock3d)
• Wood cockroach (see http://pested.unl.edu/chapter3.htm#cock3f)
Why is this animal a problem?
German cockroaches contaminate food with their droppings.
They can transmit bacterial diseases to humans that can
cause food poisoning, dysentery, or diarrhea. Many people
are allergic to cockroaches, their waste, or their body
fragments, and such allergies cause asthma in some children.
Cockroaches can damage household items, eating glue
in wallpaper, books, and furniture.
- Eliminate sources of food, water, and shelter. Fix
leaks, wash dishes frequently, seal cracks, and eliminate
clutter in kitchens, bathrooms, laundry rooms, and basements.
- Total eradication of cockroaches is virtually impossible,
but infestations can be managed. Determine the level
of infestation by using sticky traps. Kill roaches by
trapping or using pesticides, either chemical or biological.
Follow all safety instructions for any products you
choose. For a comprehensive, informative look at cockroach
life cycles and control methods, see the University
of Nebraska-Lincoln's cockroach control and identification
manual, which can be viewed online at http://pested.unl.edu/cocktoc.htm.