Pest Information
German Cockroaches
Blattella germanica
The German cockroach is the most common cockroach found in homes, apartments,
restaurants, supermarkets, hospitals and other buildings where food is stored,
prepared or served. They eat food of all kinds and may hitchhike into the
home on egg cartons, soft drink cartons, sacks of potatoes or onions, used
furniture, beer cases, etc. These cockroaches will move from building to
building during the warm summer months. They can develop into large populations
and live throughout the home, especially in kitchens and bathrooms. Cockroaches
can foul food and produce an unpleasant odor. A significant number of people
are allergic to cockroaches, and may exhibit chronic symptoms without realizing
the cause of their watery eyes or runny noses. Cockroaches can also contaminate
food with bacteria that can cause food poisoning, dysentery, or diarrhea.
Identification
Most cockroaches have a flattened, oval shape, spiny legs, and long filamentous
antennae. Immature stages are smaller, have undeveloped wings and resemble
the adults. Adult German cockroaches are light tan to medium brown except
for the shield behind the head marked with two dark stripes (separated by
a lighter stripe), which run lengthwise on the body.
Adults are about 1/2 to 5/8 inch long, have wings, but rarely fly. Wings
cover the entire abdomen of females and all except the abdominal tip in
males. The male is light brown and rather boat-shaped, whereas the female
is slightly darker with a broader behind. Young cockroaches (nymphs) are
wingless and nearly black with a single light stripe, separating two black
bands, running down about halfway of the middle of the back. Egg capsules
(ootheca) are light tan and about 1/4 inch long.
Life Cycle and Habits
German cockroach females, unlike most other cockroaches, carry ootheca that
protrude from their abdomen until the eggs are ready to hatch. The ootheca
is then dropped in a secluded location, where the nymphs emerge within one
day. A female may produce four to eight cases during her lifetime, each
containing 30 to 48 eggs. Eggs hatch in about one month, and nymphs develop
in 1-1/2 to 4 months. Adult female cockroaches live about 6-1/2 months and
males live slightly less. The German cockroach produces more eggs and has
more generations per year (three to four) than other cockroaches, thus troublesome
infestations can develop from a few individuals. This cockroach has spread
throughout the world by commerce and transportation. It is the most prevalent
pest in apartments in the United States. During the day, these cockroaches
hide in clusters behind baseboard molding, in cracks around cabinets, closets
or pantries, and in and under stoves, refrigerators and dishwashers. The
crevices behind kitchen drawers and beneath the sink are one of the primary
cockroach harborages. If clusters of cockroaches are seen during the day,
the population is large. Both nymphs and adults are very active and capable
of running rapidly. Without food and water adults may die in two weeks.
However, they can live with only water for up to a month.
Control Measures
German cockroaches can be detected by examining the premises after dark
with a flashlight and with sticky glue traps. During the day, probing hiding
places with a thin wire or thin wood strip will expose cockroaches. Adults
and nymphs usually hide clustered together. Household sprays when applied
directly to hiding places will flush and kill cockroaches. Insecticide basit
stations can also kill cockroaches. For severe or persistent infestations,
a pest control professional will provide the most cost effective control.
Prevention
In rare cases German cockroaches will move from one building to another,
however, infestations are usually initiated through the introduction of
infested materials. Inspect for cockroaches and their egg cases in sacks,
cartons, boxes, used appliances and furniture, etc., brought into the home.
Sanitation is critical in cockroach control. (Unclean living conditions
from housekeeping neglect is the major contributing factor of cockroach
outbreaks.) Thoroughly clean areas beneath cabinets, sinks, stoves, refrigerators,
etc. as well as cupboards, pantry shelves and food storage bins. Clean up
spilled foods and liquids. Avoid leaving scraps of food on unwashed dishes
and counter tops overnight. Keep food in tightly sealed containers, rinse
cans and bottles before putting in the trash, and transfer garbage outdoors
into cockroach-proof receptacles away from the house. Leftover pet foods
should not remain in the feeding dish overnight.
Insecticides
The key to controlling cockroaches with insecticides is to place the insecticides
directly where the cockroaches are hiding. Enter a dark room quietly, turn
on the light, and watch where the cockroaches run. Spot treat these hiding
places and known pathways, especially under and behind loose baseboards
or molding strips and around pipes or conduits along the walls and through
them. Do not treat entire floors, walls or ceilings. Cockroaches may hide
around the kitchen sink or drain board, in cracks underneath cupboards and
cabinets, inside the motor compartment of mechanical refrigerators, behind
window and door frames, in radio and TV cabinets, and around closet and
bookcase shelves. Surfaces used for food preparation should not be treated.
Instead, seal cracks and crevices with putty, plastic wood, or other caulking
material. Infestations in multi-dwelling housing usually require the treatment
of other units as well.
The use of "insecticide bombs" is not recommended for cockroach (or any
other insect) control. These types of insecticides are not very effective
in eliminating cockroach infestations, and can be extremely hazardous if
used incorrectly.
Traps
Cockroach traps are about the size of a large match box and have openings
at both ends. The inside surface is covered with a very sticky adhesive
and slow-release food attractant. Traps are best used to evaluate the effectiveness
of a control program, especially for brown banded and German cockroaches.
When properly placed, traps can determine harborage areas and infestation
severity, monitor effectiveness of pesticide applications, and detect any
cockroach population increases that may require additional pesticide treatments.
Traps alone will not control cockroaches. If the cockroach infestation is
severe, or if you are in doubt as to which control measures to use, contact
us for a free inspection. In most cases, it is much more cost effective
to hire a professional for cockroach infestations than attempting to do
it yourself. Moreover, these professionals have the necessary advanced training
and experience to eliminate the cockroaches quickly and safely.
