CHAPTER 11
Cockroaches
Cockroaches are a very successful group of
insects with fossil records dating back at least 280 million years. Cockroaches
have flat oval bodies, elongate antennae and heads held so as not to be visible
from above. Their front wings are leathery (tegmina) and may be well-developed
(macropterous), short (brachypterous) or lacking (apterous). In many species
the female's wings are shorter than the male's. Most common species of
cockroaches lay their eggs in cases called ootheca. Depending on the species,
there may be anywhere from 16 to 64 eggs in each case. Primarily, these are
tropical insects, with species in the
Even
though cockroaches have six legs they typically only move three at a time. The first and third leg on one side and middle leg on the other
side move in unison while the other three remain stationary forming a tripod.
Once the three moving legs touch the ground they in turn form the stable tripod
and then the first three move in unison. This sequence assures that the roach will
always have a stable tripod of legs in touch with the ground even when
running. Of course this insures the
roach can stop instantly in a dead run without falling-a phenomenon not seen in
other animals. A walking cockroach can break
into a run simply by increasing the pace of the above sequence. This may all seem pretty unimportant but it
is well documented that the cockroach is one of if not the fastest running
animals on the earth based on a proportional scale. The American cockroach has been clocked at a
speed of 59 inches or 50 body lengths per second. That is about 10 times the number the fastest
human can achieve or three times the relative speed of a cheetah. On a relative scale (body length compared
actually speed) this equates to almost 150 miles per hour. In order to achieve maximum speed some
roaches will spread their front wings thus moving their center of gravid
backward and allowing the roach to run on its hind legs only.
Subgenual
organs are located at joints on the legs and serve to detect the slightest
sound, even the footfalls of other roaches. The tip of each leg is suited with
a pair of hook-like structures (tarsal claws) and sticky pads, both of which
allow these creatures to crawl up (and even upside down) on most surfaces.
A
pair of anal cerci (Figure 10A) is located on the tip of the abdomen. These peg-like structures serve to detect
vibrations. A roach may place them on
the ground or hold them in the air and readily detect approaching danger.
One
of the more important internal organs attributing to cockroach success is the
nervous system. A roach is truly a beast with two brains. It has a large paired nerve ganglion in the
head and a single ganglion nears the posterior or rear end. These are connected by giant fibers, which
carry nerve impulses 10 times faster than normal human nerves. Experiments have shown that a warning input
from the anal cerci can be transmitted into leg movement in as little as 0.045
seconds, literally faster than a blink of the eye.
Figure 10A. A South American cockroach
with peg-like anal cerci. Image
compliments of Entophiles.
Cockroaches
are nocturnal (active at night), negatively phototropic (avoid light), and
positively thigmotactic (preferring to hide in areas where a surface touches
both the top and bottom of the body (Figure 10B). They hide primarily in cracks
and crevices. Many species are also gregarious, frequently being found together
in non-social groups. It is thought that they secrete pheromones that help them
to congregate; the function of these loose groups is not totally understood.
Figure 10B.
An American cockroach exhibiting a positive thigmotactic behavior.
Roaches are
omnivorous (feeding on all types of food). These insects will eat almost
everything humans eat and much more, including feces, book bindings, paste, and
any rotting organic matter. Cockroaches have even been found feeding under the
toenails and fingernails of patients confined to hospital beds. In some ocean freighters,
the roach populations are so large that crew-members sometimes wear socks and
gloves to bed to prevent them from feeding underneath their fingernails and
toenails.
My wife and I recently witnessed a cockroach’s
ability to find and consume food. We sat
down to dinner at a well-known restaurant.
Right next to our table was a fairly large painting. We decided to have a glass of wine before
dinner. Within minutes of arrival of the
wine, a German cockroach appeared from beneath the painting and walked out to
the middle of our table. Of course, our
reaction was not that of normal human beings and we decided to give it some
wine. I placed a small drop of wine
several inches from the roach which immediately recognized the presence of food
through its antennae (smell). It walked
over to the drop and tasted it with its maxillary palps. The roach proceeded to suck up the entire
drop (which wasn’t much smaller than the roach). It then crawled back to the picture and
disappeared. Much to our surprise,
within a few minutes the roach reappeared and came back on the table. Of course I gave it another drop and it
repeated the entire process of smelling, tasting and consuming the drop. Once finished this time it cleaned its
antennae and returned to the picture. A
few minutes later the roach dropped from the picture and began to spin on its
back. Inebriated? I would think so.
GOOD
ROACH-BAD ROACH
In
some areas of the world roaches could be considered beneficial. In tropical areas where these insects abound,
roaches play a significant role in the recycling of decaying plant and animal
matter. For example, in the Amazon
jungles a single species of forest floor roach is estimated to contribute to 6%
of the turn-over of decaying plant material.
In addition these critters are extremely important in many food chains
composing a significant part of the diet of carnivores such as birds, lizards,
rats and other small mammals. It has
also been documented that in many areas of the world some species of roaches are
important as pollinators of certain rainforest plants. Actually some roaches, especially the
tropical rainforest species, are quite beautiful (Figure 10C). Because of their relatively large size and
ease of rearing, roaches are the most commonly used specimens in studies of
insect behavior, physiology, anatomy and morphology. Finally some of the larger species (and even
smaller ones) have become quite popular as pets in the US and other countries
such as Japan. A quick search of the web
will reveal many sites that sell these seemingly disgusting critters.
Figure
10C. Some rather striking tropical
rainforest roaches. Images courtesy of
Peter Chew.
Although
in some situations these insects could be considered beneficial, a recent
survey conducted by the US Fish and Wildlife indicated that cockroaches were
the least favorite animal in the US followed by mosquitoes, rats, wasps,
rattlesnakes and bats. With many
individuals the mere sight of a cockroach can bring on nausea. One of my recent students who was enrolled in
a general education course in entomology indicated that she liked most of the
pictures on this CD we used in the class, but that every time the picture of a
roach appeared, she ran out of the room screaming.
This
fear of roaches is without a doubt a learned response. Studies indicate that children under the age
of four typically have no fear of roaches, but older children are typically
told by their parents and peers that these critters are disgusting, vile and
filthy. A personal note-our kids and
grandkids have had repeated exposure to a colony of Madagascar hissing
cockroaches that we have maintained for years.
Not one of them considers roaches to be disgusting, vile or filthy. Of course from the standpoint of a pest
control operator, the fear of roaches is not a bad thing.
The
role of roaches in the transmission of disease is well-studied. Studies indicate that about 40 different
pathogens are naturally carried by roaches, making them possible suspects in
the transmission of diseases such as polio, leprosy, bubonic plague, dysentery,
food poisoning, pneumonia, salmonella, typhoid fever and infectious hepatitis,
among others.
Certainly
the transmission of these diseases is not limited only to roaches. Water, air, hands, flies and any of a number
of other ways can also transmit such maladies.
Such transmission is referred to as mechanical, meaning that there is no
biological association between the pathogen and vector. In the case of roaches transmission is quite
simple. The pathogen is transferred from
the source to the victim externally on the exoskeleton or parts of the insect.
One of many possible scenarios could be a roach lives in a sewer and
subsequently moves to human food, thereby moving the pathogen from the source
to the food. Another possible means of
transmission is through the feeding.
When roaches feed they regurgitate partially digested food and
frequently defecate near their meal.
Again a simple scenario could be a roach feeds on feces (they seem to
love it-check your dog feces in your backyard if you don’t believe it)) and
then moves on to human food.
The
role of roaches causing allergies or asthma is well-documented. According to the National Institute of
Health, as many as fifteen million Americans may suffer from roach related
allergies. There is additional evidence
that roach related allergies may lead to allergic reactions when consuming
other arthropods such as crabs, shrimp and lobsters. Such allergies are not due to the insects
themselves but due to products of their presences such as feces, cast skins and
pheromones. Typical symptoms of roach
allergic reactions include runny nose (mild), rashes, labored breathing or in
the most severe cases death from shock (rare).
Roach allergies are more common in low-income neighborhoods (more
roaches) and when people are crowded together under unsanitary conditions and in
the northern areas with long winters where individuals are more confined to
indoor situations.
Control of
pest species is primarily with insecticides; however, proper sanitation is
important in preventing cockroaches from reaching pest levels. If food is left
exposed to these nocturnal feeders, their populations will increase much more
rapidly than if certain precautions are followed. Dirty dishes should not be
left on the sink overnight. Any accumulation of grease is especially attractive
to these insects, and it is best to store food in "cockroach proof"
containers whenever possible. Stored pet food (such as cat food or dog food)
should be closed off tightly—preferably in containers with tight-fitting lids.
As discussed, cockroaches can feed on paste, bookbinding’s, soap, paper, and
other marginal "foods." However, when forced to do so, they generally
develop more slowly and have a higher mortality rate. Once established, it is
virtually impossible to 'starve out' an infestation. Experiments indicate that
roaches can live for up to three months without food and two months without
water.
Chemical
control is based on the thigmotactic behavior of these insects. Residual
insecticides are applied to all cracks and crevices of an infested structure
and, when roaches hide during the day, the residues kill the pests on contact.
Some of the new synthetic pyrethroid insecticides are extremely toxic to
roaches. For example, one month after a surface has been sprayed with some of
these insecticides, a roach can die after merely running across it. Then, if
the tarsus of that roach is touched to the tarsi of another roach, the second
roach will die also.
These
chemicals are now readily available to homeowners. It should be noted that
these chemicals are selectively toxic to insects; that is, when properly used,
they have little effect on humans.
DOMESTIC COCKROACHES
Worldwide
there are about 5,000 species, of which only 70 are established in the United
States. Cockroaches are extremely successful animals and are thought to have
originated more than 280 million years ago. Most live outdoors and prefer a
warm, humid environment. In California, four main species are commonly found in
the habitats of humans and become pests. These domestic species are the
American cockroach (Periplanetia americana), the Oriental cockroach (Blatta
orientalis), the Brown-banded cockroach (Supella longipalpa), and
the German cockroach (Blatella germanica). All these species originated
in the tropics and were introduced into the United States via commercial
transport.
American Cockroach. This is the largest of the domestic species,
with adults rarely reaching 1 ½ inches in length; it is chestnut brown with
light-brown-to-yellow bands around the margin of the top of the prothorax
(Figure 10D). This species is also known as the sewer roach, as it abounds
there.
Figure 10D. An adult American cockroach with egg case, Periplaneta
americana.
The American
roach is primarily an outdoor species but may enter homes to feed. The life
cycle from egg to adult may require from one to two years, depending on
prevailing temperatures. In addition, adults can live up to one year. During
this time females will deposit 50 or more egg capsules which contain 16 eggs
each. This is the most common species of
roach found in sewers in the US, hence the common name sewer roach. It prefers higher temperature and humidity
and tends to replace the German roach as the most common roach found in homes
in Asia. In the US the German roach is
the most common roach found in homes since it prefers lower temperatures.
Oriental Cockroach. This is a large, shiny-black-to-reddish-brown
species, about 1 1/4 inches long, which exhibits sexual dimorphism (male and
female of a species being distinctly different in form). The females are nearly
apterous with very short vestigial wings (Figure 10E), while the males are
brachypterous with the wings covering all but the last two abdominal segments.
This species is frequently referred to as 'water bugs' because many homeowners
are reluctant to admit that they have cockroaches and also because this roach
prefers humid environments. This is primarily an outdoor species, but is common
in garages and will readily enter other structures at night to feed. A prime
location for Oriental cockroaches is water meter holes in alleys. These
cavities are dark, humid and undisturbed. The roaches emerge at night to feed
in garbage cans and from pet food dishes. The life cycle of this species is
quite similar to that of the American cockroach—one generation in as little as
one year.
Figure 10E. Left-Apterous
adult female Oriental cockroach. Right-Brachypterous male.
Brown-banded
Cockroach. This is a smaller
species which is about l/2 inch long, brown in color, and distinguished by
horizontal tan stripes on the base of the wings behind the prothorax (Figure
10F). The sexes differ in that the male is longer, narrower, and with fully
developed wings, while the female is darker, broader and has shorter wings.
This species primarily infests buildings and, when in our homes, lives
throughout the structure.
Figure 10F. A male (Left) and female (Right) brown-banded
cockroach.
German Cockroach.
This is the primary cockroach found in homes and restaurants in the
United States, with approximately 90% of roach infestations in structures
attributed to this species. This roach is about the same size and color as the
brown-banded, but can readily be distinguished by two longitudinal black
stripes on the dorsal side of the prothorax (Figure 10G). In the nymphal forms,
the stripes extend down onto the abdomen. The life cycles of the German and
brown-banded cockroaches are similar—species complete development in 60 to 90
days.
Figure 10G. An adult German cockroach carrying egg case,
the most common species found in the home.
The German
cockroach is unique in that the female carries its ootheca protruding from the
abdomen until the eggs are ready to hatch. This is to our advantage when
attempting to eradicate this pest from our homes. If a female carrying an egg
case is killed, the unhatched eggs also die. Apparently there is an essential
contact between the mother and her eggs. Eggs of most insects are difficult to
kill with pesticides. Unfortunately, the American and Oriental cockroaches
randomly drop their egg cases soon after they are formed. The brown-banded
cockroach attaches their egg cases behind objects, such as drawers and picture
frames.
The German cockroach has a faster life-cycle
and lays more eggs than any of the other common house infesting roaches. As a consequence it tends to increase in
numbers more rapidly than these other species.
Under ideal conditions this insect can produce three to four generations
per year. In addition each female can
produce up to eight ootheca which can contain 30 to 40 eggs each. Their reproductive capacity, plus the fact
that the environmental conditions that are typically found indoors are ideal
for their development lead to their major pest status.
A simple comparison of the potential
reproductive capacity of the German and Oriental cockroach (or actually any of
the other pest species) will illustrate the difference of each. On average a female Oriental cockroach
produces five egg cases containing 16 eggs each and after hatching, the nymphs
require a year to grow to adulthood. A
simple calculation indicates (assuming 100% survival) that a mated female
Oriental cockroach is capable of producing 80 adult roaches in a one-year
period. On the other hand a female
German cockroach produces an average of eight egg cases containing 16 eggs
each, which after hatching complete development in three months. As a result after three months one female
would produce 108 adults, half of which are female. In turn those females would produce 5832
adults in another three months. Assuming
two more generations after one year, a single female German roach is capable of
indirectly producing 17, 006,112 offspring or 212,576 times as many offspring
as the female Oriental roach. It should
be emphasized that this is a hypothetical calculation and there are many
factors that greatly reduce the reproductive capacity of roaches, but it does
give great insight as to why the German roach is so much more of a pest than
the other domestic species.
During the
1950's and 60's, if a home was infested with German cockroaches, they were
almost exclusively confined to kitchens and bathrooms. Over time, infestation
gradually began to be seen in different areas of the home; today they
frequently are spread throughout the structure. This apparent change in cockroach behavior can be explained
by a combination of changes in human
behavior and home construction since the 1950's.
German
cockroaches prefer environments with high humidity, high temperature and
available food. Fifty years ago the family normally sat and ate dinner and
other meals together in the kitchen. Today, due to busy schedules, two-income
families, and the advent of television, families rarely eat meals altogether or
in the kitchen. Consequently, crumbs and other droppings are spread throughout
the home and attract these roaches. Higher humidity in the 1950's was typically
confined to the bathroom and kitchen. Older homes were usually built with one
bathroom. However, bathrooms in newer homes frequently are found in several areas.
As a consequence, there is increased humidity throughout the structure. Also,
with the advent of central air conditioning, moisture tends to condense in wall
voids where the cool room air meets the hotter outdoor air. Finally, there has
been a tremendous increase in the number of televisions, computers and other
small appliances in homes; these are sources of heat that attract German
roaches. Additionally, while sitting for long periods at the computer or
television, we often have a little snack (or a full-blown meal). The
combination of heat, high humidity and food must be irresistible to
cockroaches!
German
cockroaches can reach tremendous populations in a fairly short period of time
if the right conditions exist. Recently, there have a number of lawsuits
throughout the U.S. where tenants are suing slumlords for continuous unsanitary
and run down conditions. Large rat and German cockroach infestations are a
considerable part of the problem. In some cases, the tenants have actually won
the apartment complexes as part of the settlement.
We recently
visited one of these heavily infested complexes in Los Angeles. Upon entering
one of the units, over a hundred roaches were sitting or running about on the
walls. This was quite unusual because it was day time and roaches, of course,
are nocturnal. Normally, in structures where roaches are active during daylight
hours, it is an indication of a very large infestation as they probably have
run out of places to hide. The tenant indicated that conditions had become
intolerable: a bowl of food could not be placed on the kitchen table without it
being visited by hoards of roaches. On several occasions roaches were found
hiding in the ears and up the noses of sleeping children. The ultimate insult
was when one of the tenants was feeding her two-year-old and a roach crawled
out of the child’s mouth.
If that story
grosses you out, I suggest you not read the rest of this paragraph. Recently a
doctor friend was examining an extremely overweight lady. She claims that she
was examining an area between two flaps of fat on the patient's arm and she
first found cookie crumbs and then a few German cockroaches living in this and
several other areas of the woman’s body. The doctor was repelled by the finding
and required the patient to take a shower before continuing the examination.
Although I am sure this is exceedingly rare, it does make biological sense.
Such a situation meets all of the biological requirements for this species:
food, heat, high humidity and a thigmotactic location.
OTHER ROACHES
Madagascar Hissing Cockroach. This roach is an African species that has
gained considerable notoriety due to its use in a number of movies (e.g. Damnation Alley, Indiana
Jones and the Temple of Doom, and Men in Black). Adults may approach
three inches in length and are capable of producing a hissing sound when disturbed
(Figure 10H). Contracting the body and expelling air out the trachea (internal
breathing tubes) through the slit-like openings of these tubes to the outside
produces this noise. This hiss mimics that of a snake and is a
startle-defensive mechanism possibly used to ward off attacking predators. Male
roaches also use hissing while mock fighting over females. Males can easily be
distinguished from females by the presence of two small projections on the
prothorax.
Figure 10H. Left.
Male Madagascar hissing cockroach with hornlike projections on top of
prothorax. Right-Female.
The
effectiveness of this defensive mechanism was recently documented in our own
home. I brought a box of hissing roaches home from school several years ago.
They escaped by pushing open the lid of the box. I assured my wife that they
were a tropical species and would not survive in our home. I was proven wrong
two years later when we turned over our round oak table and there was a mother
and her babies living in the hollow pedestal. Since then, one summer night a
loud hissing in the front room wakened us. Upon inspection, our cat was
sneaking up on a large roach, only to jump several feet in the air after the
pounce of the cat and resultant hiss of a Madagascar roach.
Finally male roaches apparently stimulate
female to mate with their hiss. In one
experiment the spiracles of male roaches were sealed preventing the ability to
hiss. When placed with females these
individuals were no longer attractive to females until the sound of hissing
roaches was reproduced with a tape player.
Rhinocerus
Cockroach.
This is certainly one of the largest species of cockroaches in
the world (Figure 10I)-perhaps the largest. Their distribution is limited to
northern Queensland and reaches a length of 3 ½ inches and a weight of 30 grams
(the weight of 2 sparrows). This is a
burrowing species that forms permanent tunnels in sandy soil that may reach a
depth of several feet. They emerge at
night to feed on dried leaves that they frequently drag into their
tunnels. As with hissing roaches the
young are born alive. They have a very
long life cycle and require up to seven years to reach adulthood.
Figure
10I. A giant rhinoceros cockroach.
In
Australia they are frequently kept as pets and can be purchased in some pet
stores where they are known as macrodogs.
They have not reached the pet trade in the US to any extent as it is
illegal to export any insects (dead or alive) from Australia. Of course there are always some exceptions to
the rule. In this case if insects are
captive bred they can be exported.
As
with some of the larger insects they are being bred in captivity in Japan and
are sold for several hundred dollars each in that country. Insects as pets in Japan have become very
popular. I am sure part of the reason is
due to the lack of living space and insects take up very little space. In many cases these insect pets sell for very
high prices. I had a friend who was
doing some work for National Geographic and ran across a new subspecies of a
common rhinoceros beetle. He managed to
collect 20 pair and brought them back to Japan and sold them to an insect
breeder for $10,000 a pair.
Cockroach Control
Preventative
Treatment
Typically cockroach infestations do not
appear in the home or other structures on their own. In some situations the
Oriental, smoky brown, American and other predominately outdoor inhabiting
species of cockroaches may move indoors on their own. On the other hand, the
German and brown-banded roaches are nearly always brought into homes by human
activity. There are some records of German roaches mass migrating from one
structure to another but this is extremely rare. Once established, roaches have
the potential to breed to huge numbers in a relatively short amount of
time. As mentioned one female German
cockroach and her offspring have the potential of producing over a million new
roaches after three short generations.
Obviously this potential is never reached or we would be literally
swimming in cockroaches. A number of
factors limit this potential including natural mortality, available space,
predators and parasites, availability of food and water and prevailing
temperatures and humidity to name a few.
The presence or absence
of these factors becomes very important in cockroach control. All structures have a limited capacity
(carrying capacity) to support a certain number of cockroaches. Biological
factors attempt to keep an insect population at that level, regardless of
measures taken to reduce the population, like pesticide applications. For
example when a number of cockroaches die after an insecticide application, the
reproductive rate of the remaining roaches will increase to replace those
individuals and keep the population near the carrying capacity.
An important phase of
cockroach control is to attempt to reduce the carrying capacity of an infested
structure. In some cases the pest
control operator will not be able to accomplish this on his or her own, but he
or she can educate the client and thereby increase the chance of successful
control.
The most important
factors that can be controlled to reduce the carrying capacity of a structure
are the availability of food, water and space.
A very small amount of water (much less than a drop) is all that is
needed to maintain a cockroach for weeks, if not months. Any source will
suffice including condensation on pipes, small leaks, moist sponges, soaked
wood or even moist food. Cockroaches eat almost anything, including: crumbs,
hair, fingernail clippings, feces, paper, spots of grease, oiled clothes, pet
fur and dead insects (even dead cockroaches). They will cannibalize their own
young and egg cases if food becomes scarce. Food high in protein or containing
significant moisture content is very attractive to cockroaches. However, if
forced to feed on less nutritious food such as wood, soap, fingernails etc.
their natural mortality rate will increase.
As previous
discussed, domestic roaches are positively thigmotactic meaning they hide
during the day where they have a surface touching the top and bottom of their
bodies. This normally equates to crack
and crevices that are around 1/16th inch wide. They also prefer to
sit on wood and paper rather than metal surfaces. Their flat body allows them
to squeeze into places where they can touch the surfaces above and below at the
same time. Additionally the warmth around
motors of dishwashers and refrigerators is attractive, especially if there is a
drip pan under the refrigerator which provides water. In summary, one of the
aims of a successful pest control program should include the reducing the
availability of those factors (discussed above) that determine the carrying
capacity of a structure.
Limiting the Availability of Water
Plumbing. Of the factors discussed above this is probably the most important in
reducing cockroach populations. As with humans roaches can survive much longer
without food than they can in the absence of water.
Plumbing is one of the most common sources
of water for these insects. Any leaking faucets including the gasket at the
base should be repaired. Normally if a faucet leaks at the base this occurs
when the water us running. Roaches
commonly crawl up into faucets for water so the screen that breaks the flow of
the water into a steady stream should be in place. The plumbing underneath the sink, especially
when the water is off, should be checked for leaks and repaired. A whitish residue
around these pipes indicates a slow leak.
Pipe
insulation may be needed to prevent cold water pipes from sweating during humid
conditions in the summer. There is enough moisture on sweating pipes to sustain
a sizable cockroach infestation. The insulation should be sealed to prevent
roaches from hiding between the insulation and the pipes. All drains should be
covered with a fine mesh screen. Most
kitchen sink strainers will not keep cockroaches from going down the drain for
moisture.
Other Water Sources.
Damp dishrags or sponges are an ideal
source of moisture and even bits of food.
These can be rinsed with a mild ammonia solution or placed in a plastic
bag. Potted plant dishes with standing
water or even moist soil in plant pots can be a source of moisture. A layer of
gravel over the soil will eliminate the latter sources. Other sources of water could include pet
water dishes and refrigerator pans.
Limiting Food Supply.
Sanitation start with a
through clean up of the cooking area. This starts with cleaning behind and
under the stove, refrigerator and freezer, if present. The outside of the appliances should also be
cleaned. A tremendous amount of food
refuse accumulates under the stovetop.
Particular attention should be paid to any accumulation of grease which
is roach caviar. Cockroaches readily
feed on the film of grease on oven hoods and walls next to or behind where
frying pans, or grills are used.
When possible foods
should be stored in cockroach proof containers.
This isn’t as simple as it seems as these beasts can chew their way
through most types of packaging including thin soft plastic, aluminum foil,
paper and cardboard. No open food should be left out overnight, especially on
dirty dishes in the sink. It is difficult to completely deprive cockroaches of
a food source, but limiting food resources makes it easier for other control
methods to work effectively.
Unlike humans roaches
make no distinction between garbage and a gourmet meal. A garbage disposal is very helpful in
reducing waste in the home. However, the garbage disposal must be used daily or
whenever waste is deposited, and it should be flushed thoroughly after each
use. If a top cover to the drain leading to the disposal is available this
should be in place when not in use. All food preparation surfaces, pots and
pans and dishes should be thoroughly cleaned as soon as possible after eating
but certainly before retiring.
Eliminate
Hiding Places.
Keep in mind roaches
prefer to be in tight, small places and to rest on porous surfaces such as
wood, cloth and paper. Stainless steel, aluminum, plastic laminates, ceramic
tiles or baked enamel surfaces are less preferred for resting. When these
"soft" materials are layered (such as corrugated cardboard), it forms
an ideal site for cockroach resting and breeding. Do not keep paper bags,
sacks, cardboard boxes, rags or pieces of wood in locations where cockroaches
may be present. One of the biggest mistakes is to store paper sacks next to the
refrigerator because it provides a layering effect next to a warm area and high
source of humidity. Equally troublesome is the storing of paper bags in layers
in kitchen drawers.
Ideally narrow cracks,
seams and crevices should be sealed in order to reduce the hiding places of
roaches. Frequent hiding places include behind molding, small holes, around
rubber gaskets on refrigerators and freezers, in seems beneath kitchen tables
and where cabinets or walls meet, or around built-in appliances. Caulking is the most commonly used method to
seal most of cockroach hiding places. Of the various types available silicone
caulks are preferred as they do not shrink, crack and cannot be chewed through
by roaches.
Inspecting
for Infestations.
The first consideration in
inspecting for a cockroach infestation is to identify the roach or roaches you
are dealing with. Once identified then
the knowledgeable operator will have a better idea as to where he or she would
likely find the roaches. For example German
roaches and brown banded roaches may be spread throughout the house and
Oriental and American roaches are more likely to be found outdoors or in warm
moist situations in the home. One of the
chief tools is a good flashlight, which is needed to examine those hidden dark
locations where roaches are likely to occur.
Also a long handles mirror may be of use in checking those hard to reach
locations.
Chemical Control
Chemical
control becomes more difficult for the homeowner as opposed to the professional
exterminator. The main advantage the
professional has is the range of products available. However there are effective products
available to the homeowner. It is
important to read the pesticide label before selecting a product and precisely
follow its directions when using any pesticide product. Most importantly the product should be
developed for roach control and should have some residual activity, meaning
once it is applied it should remain active for days if not weeks at least. It is not important to apply the chemical
directly to the roach but more important to apply it to where the roaches hide
during the day. Keep in mind that
roaches are positively thigmotactic and hide in cracks and crevices. Generally
speaking roach motel type products and aerosol bomb are not that effective in
this offers opinion.