German Cockroach, Blattella Germanica
D. R. Suiter and P. G. Koehler
The German cockroach ( Figure 1 ) is about 5/8-inch in length, brown in color,
with two dark longitudinal streaks on the pronotum. The male is light brown
and somewhat boat-shaped. The female is slightly darker in color with a
broader and rounded posterior. Nymphs are similar in appearance to the adults
but wingless with 2 dark bands running halfway down their back. Nymphs range
in size from 1/8 to 1/2 inch in length.
It is the most prevalent species in and around homes, apartments,
supermarkets, food processing plants, and restaurants. Ships, especially
cruise ships and naval vessels, can also be heavily infested. During the day
in houses, they hide in cracks and crevices such as under kitchen appliances,
sinks cabinets, behind baseboards and moldings, in wall voids, pantries and
similar areas of homes and restaurants. In commercial establishments such as
food plants, warehouses, supermarkets, etc, they can be found in cardboard
containers, wooden boxes, and under pallets.
Biology and Habits
The German cockroach breeds throughout the year indoors, but favors a humid
environment and an average temperature of approximately 80° F. A life cycle
can be completed in about 3 months. The German cockroach produces more eggs
per capsule than other pest cockroach species, and its young complete their
growth in a shorter period of time. Female German cockroaches carry their egg
capsules until they are ready to hatch. The number of eggs in a capsule
usually is between 30-40, with a maximum of 48. The average number of nymphs
hatching is 30. The average incubation period at 76° F was 28.4 days. Capsules
removed from the female do not usually hatch. Females at room temperature may
produce an average of 4-5 capsules in her life time.
The time for nymphs to mature to adults averages 103 (54-215) days. They
progress through 6-7 nymphal instars in 60 days for males and 65 days for the
females. Females may live for more than 200 days.
The German cockroach is spread by commerce and transportation, as well as by
its migrations. Many homes and business establishments become infested with
German cockroaches when they are introduced in infested cartons, foodstuffs,
and other materials. The German cockroach appears to be extending its range
into nontraditional sites in buildings due to the availability of water in
many areas. Plants are often located throughout the house or workplace, drinks
are often carried or left anywhere, consequently German cockroaches are able
to get sufficient moisture and food to survive.
Reprinted with thanks to;
University of Florida, Institute of Food and Agricultural
copyrighted by the University of Florida, Institute of Food and Agricultural
Sciences (UF/IFAS) 11/28/04
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