IDENTIFYING COCKROACHES IN AND AROUND
At the end of this course there will be a test consisting
of 10 random questions. PRINT out the test and answer
then Fax to: (512) 990-0665
or mail the test to:
P.O. Box 81552
Austin, TX 78708-1552
Once received, the questionnaire will be reviewed and a Certificate
will be issued. The governing agency will be notified of your
CEUs. We will maintain your records for the appropriate time
IDENTIFYING COCKROACHES IN
AND AROUND THE HOME
One of the most common insects
found in and around man-made structures is the cockroach. The cockroach
is often labeled as a repulsive, filth-carrying, food-contaminating
creature. Controlling cockroaches in and around the home is a continuous
battle. If effective, economic control is to be achieved, we must
be able to positively identify the species that we are dealing with.
It has long been said that the cockroach is one of the most
successful and adaptive organisms on earth.
Cockroaches are one of the most ancient of all insects. Fossil
evidence indicates that they have been on earth for over 300
million years. When compared to the cockroach, man has been around
for only the blink of an eye. More than 200 species of fossilized
cockroaches have been found in North America and Europe. Several
species have been found in Baltic amber.
At the present time more than 4,000 species of cockroaches
have been described and named. Close study of fossilized cockroaches
has revealed that very little change has occurred in the cockroach
over time. The present day species are very much like their ancient
The cockroach's nearest relatives include the grasshoppers,
crickets and mantids. A distant cousin of the cockroach is the
Cockroaches are world wide in distribution. Most species are
found in the tropics. In the U. S. A. we have 49 native species
and several introduced species. Most of these are found in the
LIFE HISTORY AND HABITS
The name cockroach is thought to have been derived from the
Spanish name for the insect, "cucaracha". Many of the
most common species have an accepted common name, and some have
one or more aliases.
Cockroaches range in size from a fraction of an inch to several
inches in length. Their color in generally brownish to blackish,
but some are yellowish, tan or green. A few species are marked
with spots or stripes of bright red, yellow, black and even metallic
Cockroaches are flattened dorsoventrally, or from top to bottom.
They are oval to oval-elongate in shape and are often described
as being "football-shaped". Their head is often partially
or totally concealed by their large shield-shaped pronotum. Their
legs are relatively long and are often very spiny. Their antennae
are long and filament-like. Their mouth parts are well developed
Most cockroaches have two pair of well developed wings. The
front pair of wings (forewings) overlaps over the back. They
are narrow, thick and leathery. The hind pair of wings are membranous
and are folded fan-like beneath the front pair. Many cockroach
species are wingless and others have only rudimentary wings.
In some species, the females have wings that are shorter than
the males, and they may appear so different that they can mistakenly
be taken as being two different species.
Cockroaches have two tail-like appendages at the posterior
end of their abdomen. These structures are called cerci. The
cerci are very prominent in the nymphs, but in the adults they
are often covered by the wings and are not visible from above.
Immature cockroaches resemble the adults except they do not
have wings, and they are smaller in size.
Cockroaches develop through gradual metamorphosis. They have
three distinct life stages. These are the egg, nymphal and adult
stages. Females lay eggs that are enclosed in capsules called
ootheca. Each ootheca may contain from just a few to about 40
eggs depending upon the species. Each female may produce from
less than ten to more than 50 ootheca in her lifetime. The ootheca
is carried at the end of the abdomen of the female until it is
hardened. This is usually one or two days. It is then deposited.
The ootheca are usually attached, or glued, in secretive places,
to a structure or object. Each species has its own preferred
oviposition sites. Some species will carry the ootheca at the
end of their abdomen and not deposit it until the eggs are ready
to hatch. Depending upon the species, the nymphs begin to hatch
in about 30 to 90 days.
The nymphs go through several molts. Each time they increase
in size and look more like the adults. Some species of cockroaches
may complete a life cycle in about 60 days. Other species require
about three years. The number of offspring from one female cockroach,
in a single year, may range from several hundred to several thousand,
depending upon species.
| In some species of cockroaches
the females have wings that are shorter than the wings of the
| Some species
of cockroaches are wingless and some have wings that are not fully
developed, or rudimentary.
| The life cycle
of the cockroach may be completed in 60 days in some species,
but it may take as long as three years in other species
Although most cockroaches are very good fliers, they are highly
cursorial. That is, they are adapted to running. Most species
had rather run than fly. Some can run rather rapidly, while other
species are rather slow moving.
Cockroaches continuously expel secretions from their body
and regurgitate fluids from their mouth. These fluids are deposited
on the surface of objects in the area that they frequent. When
this liquid dries, it leaves dark "specks". These specks
may be so numerous that large areas on a contaminated surface
may appear "blackened".
Cockroaches give off a very offensive odor. Persons that are
sensitive to this odor can detect cockroaches by their smell
long before they see the pests. This odor is often imparted to
food making it unfit to eat. The odor may also linger on dishes
for a very long time. Even after washing, the odor may still
be detected when dishes are heated.
Most species of cockroaches are highly gregarious. Large numbers
are often found crowded into favorable habitats such as behind
loose wallpaper, in dark corners, or behind appliances. Many
species of cockroaches have become very well adapted to living
with man. They will move into your house, eat your food, sleep
in your bed and even get in your clothing. The travels of man
have spread numerous species, far and wide. They travel with
us by air, by land and by sea. They stowaway in our luggage,
in our vehicles, our furniture, in various containers and even
in our food.
Although most heavy infestations of cockroaches are associated
with filth and poor sanitary conditions, infestations know no
social barrier. Sooner or later everyone will have at least a
few cockroaches in their home.
Cockroaches find their way into our dwellings through faulty
doors and windows, through cracks and crevices, down chimneys
and through vents. They may enter where we pass wires, pipes
and cables through the walls. We also bring cockroaches into
our homes as we bring in furniture, clothing or appliances. We
bring them in when we bring in firewood, groceries, pet food,
cartons and other containers.
Cockroaches prefer warm moist surroundings. Most species prefer
to stay on the ground floor or in the basement, rarely going
upstairs. They are nocturnal (night active) and are seldom seen
in the day unless their numbers are very high. During the day
they hide in secretive places such as behind baseboards, between
walls, in cabinets and drawers, under and around sinks and lavatories
and behind appliances.
Cockroaches are omnivorous and will feed on almost anything.
They feed on grease, starchy materials and sweets. Some species
have a preference for one type of food over another. They often
cause damage to household goods, furniture, and clothing. They
will feed on leather, fabric, wallpaper paste, paper and bookbinding.
These pests will also feed on various waste materials, their
own cast skins and on live or dead insects.
It is hard to believe, but in Europe, powdered cockroaches
were once sold as a remedy for pleurisy and pericarditis.
It is hard to believe, but cockroaches have never been positively
linked to the transmission of pathogenic organisms that infect
man. However, the potential for cockroach transmission of certain
pathogens, under specific conditions, is undeniable. Cockroaches
frequent many sites where they can be contaminated with disease
organisms. Afterward, they frequently come in contact with man
and this is a potential situation where transmission of these
pathogens could occur.
Some areas that cockroaches frequent, where they may pick
up pathogenic organisms include human feces and spittle, garbage,
sewers, dying and dead animals. Also, cockroaches have been known
to crawl on and to nibble at the bodies of helpless infants,
incapacitated, ill or sleeping persons and even on human cadavers.
Pathogens acquired at these sites could potentially be transmitted
to man as they crawl over food, dishes, silverware and other
Laboratory experiments have shown that cockroaches can harbor
thousands of bacteria. About 40 species of pathogenic bacteria,
two species of pathogenic fungi, several protozoa, and four strains
of poliomyelitis virus have all been isolated from wild-caught
It is a known fact that some people are allergic to cockroaches.
Contrary to common belief, it is not the repulsive odor of the
pest that people are allergic to. Allergic reactions come from
a protein found in the pulverized bodies of dead cockroaches
and from their feces.
Of the 4,000 species of cockroaches in the world, the U.S.
has about 55 species. This includes 49 native species and about
six or seven introduced species. Although a number of species
may be found occasionally or accidentally in the home, there
are only five species that are considered as common pests in
the dwellings of man. These most common species are GERMAN COCKROACH,
AMERICAN COCKROACH, ORIENTAL COCHROACH, BROWN-BANDED COCKROACH
and the SMOKY-BROWN COCKROACH.
Any attempt to control infestations of cockroaches is greatly
enhanced by the positive identification of the species that you
are concerned with. Knowing the species enables you to determine
the biology, preferred habitat, feeding habits and the proper
control technique for the species in question.
Cockroaches are known by several common names. Some of these
names are recognized worldwide, some are recognized nation wide;
others are recognized in only a small specific geographical location.
Common names may vary from place to place and their use may
be confusing. Each species of cockroach has an accepted scientific
name, which is composed of its generic and its species name.
The scientific names of species will be given here to facilitate
further study and to assure that you are studying the species
with which you are concerned.
SCIENTIFIC NAME - Blattella germanica
ACCEPTED COMMON NAME - German cockroach
ALIAS - Prussian cockroach, croton bug, water bug
SIZE - 1/2 to 5/8 inch long (10 - 13 mm)
COLOR - The German cockroach is a uniform drab brown.
Its legs are a bit lighter in color than its body. The pronotum
has two wide, black longitudinal stripes. Between these longitudinal
stripes there is a golden brown stripe that extends past the
pronotum onto the wings.
DISTINGUISHING CHARACTERISTICS - The pair of black stripes
on the pronotum is the most distinguishing characteristic of
the species. This with its small size can usually identify the
COMMENTS - The German cockroach is native to Europe.
It is the most widely distributed and best known species in
It is the most pestiferous species in restaurants, grocery
stores, multi-unit dwellings and in many homes. This species
is most frequently found in kitchens and bathrooms, but under
heavy populations it may be abundant anywhere in a dwelling.
It is common to see females of this species carrying an egg
capsule at the end of her abdomen.
SCIENTIFIC NAME - Periplaneta americana
ACCEPTED COMMON NAME - American cockroach
ALIAS - palmetto bug, water bug
SIZE - 1 1/2 - 2 inches long (27-45mm)
COLOR - The American cockroach has a uniform light reddish-brown
body. Its yellow-brown pronotum has a golden-yellow border.
Its legs are also a golden-yellow.
DISTINGUISHING CHARACTERISTICS - The American cockroach
has two distinguishing characteristics. One is its size, and
the other is the golden-yellow area around the outer edge of
COMMENTS - The American cockroach is world wide (cosmopolitan)
in distribution. It is the largest species and the second most
common species found in homes in the U.S.
Some authorities believe that this species is a native of tropical
or subtropical America. Others believe it to be a native of
This species is capable of flying long distances but seldom
flies at all.
The species thrives in man-made structures. In homes it is
most often found in kitchens and bathrooms. It also frequents
sewers and steam tunnels.
Females carry their ootheca for one or two days before depositing
SCIENTIFIC NAME - Supella longipalpa
ACCEPTED COMMON NAME - Brown-banded cockroach
ALIAS - tropical cockroach, T V roach, furniture cockroach
SIZE - 1/2 inch long (10-14mm)
COLOR - The head and thorax of the brown-banded cockroach
is dark brown to almost black. Its wings are also dark brown
but banded with light brown. The legs are light brown and have
small dark spots at the joints.
DISTINGUISHING CHARACTERISTICS - The most distinguishing
characteristic of this species is the presence of a light colored
band at the base of the wings and another about 1/4 inch down,
toward the tip of the wing. The pronotum of this species is
rather small and the head is very prominent.
COMMENTS - The Brown-banded cockroach frequents homes,
hotels, apartments and hospitals. It resembles the German cockroach
but is smaller in size.
The species is very gregarious. It readily flies when disturbed
and often jumps when trying to escape danger. When searching
for food, it often stands erect on its legs.
The wings of the male covers its abdomen, but the wings of
the female do not.
The light colored bands on their back are more easily detected
in the nymphs than in the adults.
SCIENTIFIC NAME - Blatta orientalis
ACCEPTED COMMON NAME - Oriental cockroach
ALIAS - black beetle, shad roach
SIZE - 1-1.25 inches long (18-30mm)
COLOR - The oriental cockroach is dark brown to almost
black and rather uniform in color. Its legs are about the same
color as their body but can be slightly lighter brown.
DISTINGUISHING CHARACTERISTICS - The oriental cockroach
may be distinguished by its large size, robust shape and dark
color. The short wings of the male and the rudimentary wings
of the female are also distinguishing characters.
COMMENTS - The oriental cockroach is worldwide in distribution.
It is normally an outside species, but will move into the home
during cold weather. It is commonly found in lawns, along the
foundation of buildings, in water meters, in basements and in
piles of rubbish.
It is rather slow moving and sluggish, for a cockroach, and
neither sex can fly.
SCIENTIFIC NAME - Periplaneta fuliginosa
ACCEPTED COMMON NAME - Smoky-brown cockroach
ALIAS - black beetle, shad roach
SIZE - 1-1.3 inches long (24-33mm)
COLOR - The smoky-brown cockroach is very uniform dark
brown to black in color. If there is any differentiation in
color at all, the legs and the pronotum may be slightly darker
than the rest of the body.
DISTINGUISHING CHARACTERISTICS - If this species has
any characteristic that would help in distinguishing it from
other species, it would have to be its large size and the dark
uniform color of the pronotum.
COMMENTS - The smoky-brown cockroach is a very close
relative of the American cockroach. It is mainly a pest in the
eastern and southeastern U.S. This species is common outdoors
in compost piles, woodpiles and rubbish. It is more and more
becoming a pest of homes, warehouses and other man-made structures.
SCIENTIFIC NAME - Periplaneta australasiae
ACCEPTED COMMON NAME - Australian cockroach
ALIAS - black beetle, shad roach
SIZE - 1 inch long (23-29mm)
COLOR - The Australian cockroach closely resembles the
American cockroach. It is reddish-brown to dark brown. It has
yellow markings on the pronotum and on the front edge of each
DISTINGUISHING CHARACTERISTICS - The Australian cockroach
may be distinguished from its near relative, the American cockroach,
by the straw-colored to yellowish streak extending about 1/3
of the way down the outer margin of the wings. Also, by the
wide yellowish area around the margin of the pronotum which
leaves a "double" dark spot in the middle of the pronotum.
COMMENTS - The Australian cockroach is probably not
indigenous to Australia. In the U.S., it is found mainly in
the southern states.
This species often is found in greenhouses and around structures
It feeds mostly on plant material, but in the home it will
feed on starchy materials.
SCIENTIFIC NAME - Periplaneta brunnea
ACCEPTED COMMON NAME - Brown cockroach
SIZE - 1-1.3 inches long (25-33mm)
COLOR -The brown cockroach is reddish-brown in color
and has yellow margins on the pronotum.
DISTINGUISHING CHARACTERISTICS - This species is a bit
darker in color than the American cockroach. Also, the wings
of the male are not as long as the wings of the male American
cockroach. The ootheca of the Brown cockroach is about twice
as long as the ootheca of the American cockroach.
COMMENTS - The Brown cockroach is found in the southeastern
and the southern states, from Florida to California.
SCIENTIFIC NAME - Blattella vaga
ACCEPTED COMMON NAME - Field cockroach
ALIAS - vaga cockroach
SIZE - 3/8-5/8 inch long (8.5-11.5mm)
COLOR -The field cockroach is light brown. It has a
black face and two black longitudinal stripes on the pronotum.
This species has been described as being olive-green in color.
DISTINGUISHING CHARACTERISTICS - The Field cockroach
is smaller than its close relative, the German cockroach. The
black area on the front of the head is the most distinguishing
COMMENTS - The field cockroach is found from Texas to
California. It is normally found outside but will occasionally
enter homes. It is somewhat active in the day.
SCIENTIFIC NAME - Blattella asahinai
COMMENTS - The Asian cockroach is native to Southeast
Asia. It is a relative of the German cockroach, but it prefers
the outside. The species is now established in Florida and is
working its way westward. It is a strong flier and is attracted
SCIENTIFIC NAME - Blattella surinamensis
SIZE - 0.5-1.0 inch long (16-23mm)
COLOR - This species is shiny brown to black.
DISTINGUISHING CHARACTERISTICS - In this species the
wings extend beyond the tip of the abdomen in both sexes. The
posterior margin of the pronotun in the adult is sinuate (curved
in and out). In some specimens, the anterior margin of the pronotum
is marked with a pale band.
COMMENTS - The Surinam cockroach is found worldwide.
In the U.S. it is established in Florida, Louisiana and Texas.
This species is generally found outside under boards or litter.
It is often a pest of greenhouses. In the U.S. the species is
parthenogenetic, no males have ever been found.
SCIENTIFIC NAME - Panchlora nivea
SIZE - 0.5-0.75 inch long (12-18mm)
COLOR - The Cuban cockroach is pale green in color.
Its head, pronotum and the front half of the front wings are
a bit lighter in color.
DISTINGUISHING CHARACTERISTICS - The green color alone
is most distinguishing for the species. Most specimens have
a small brown spot about 1/3 of the way from the end of their
COMMENTS - The Cuban cockroach has been known to establish
populations in parts of Florida and in Brownsville, Texas.
Pennsylvania Wood Cockroach
SCIENTIFIC NAME - Parcoblatta pennsylvanica
SIZE - Female is 0.5-0.75 inch long (12-18mm), male
is 1.0-1.25 inches long (22-30mm)
COLOR - This species is very light brown. Its thorax
and wing pads are edged with white.
COMENTS - This species is indigenous to the U.S. and
ranges from the southeast to the Midwest and into Canada. The
males are much larger than the females and have fully developed
wings. The wings of the females are very small and are nonfunctional.
The males fly readily and are attracted to lights.