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German cockroach (Blattella germanica)
The German cockroach 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.
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. |
