Environmental Engineering Reference
In-Depth Information
Figure 5.5
Major cockroach species. (Courtesy of Ogg, C., University of Nebraska.)
association between insect allergens and respiratory disease has been that
of cockroaches.
Cockroach species of concern include the German cockroach (
Blattella
germanica
), American cockroach (
Periplaneta americana
), and Asian cockroach
-
ronments. The German cockroach appears to be the most important, partic-
ularly in the northern U.S. where it is the most prevalent species, especially
in large, densely populated cities. They are commonly found in houses,
restaurants, and schools.
As adults, German cockroaches attain a length of approximately 17 mm.
Like other cockroaches, the body is oval-shaped and flattened, with spiny
legs and long, filamentous antennae. German cockroaches consume a variety
of foods and may infest buildings by being brought in on materials infested
with one or more life stages. They are most commonly found in kitchens
and bathrooms. Populations of thousands to tens of thousands of individuals
may develop within a single building. Being primarily nocturnal creatures,
they feed at night, hiding in cracks and other dark spaces during the day.
Female cockroaches, on average, live about 200 days, with the male life
span somewhat shorter. Females produce 4 to 6 egg cases in their lifetimes,
with each case containing 30 to 40 eggs. One female cockroach may produce
several hundred young within a period of approximately 6 months. As a
consequence, only a few initial individuals are needed to cause a significant
infestation problem.
Cockroach allergens are found in fecal material and saliva, as well as
other body parts. Two major German cockroach allergens have been identi-
fied, Bla g I and Bla g II.
Cockroach allergens are determined from floor dust samples using mon-
oclonal antibody assays. Concentrations are reported in units per gram
(U/g). Preliminary evaluations by medical scientists indicate that a floor
