Cockroaches are a paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. A cockroach has a flattened, oval body and long antennae that is about the length of their body. It has six strong legs covered with spines. Many adult roaches have fully developed wings, but only few fly. Young, immature cockroaches resemble adults but are smaller and do not have wings.
Cockroaches are among the most common pests infesting homes and apartments. They are especially troublesome where food is prepared and sanitation is lacking. Cockroaches are repulsive and embarrassing to most people simply by their presence. They may contaminate food, kitchen utensils, and other household items, and they leave an unpleasant odor.
Because cockroaches move freely from filth to food, they can transfer pathogenic microbes that cause food poisoning and other illnesses. Many people are also allergic to cockroach excrement and their shed skins. Cockroach-produced allergens may cause congestion, sneezing and watery eyes, as well as life-threatening bronchial inflammation (asthma) characterized by recurrent cough, wheezing, and difficulty breathing. Asthma triggered by cockroaches is especially common among children living in densely populated housing conditions where infestations are often severe.
COCKROACHES CONTAMINATE FOOD AND CAN TRANSMIT HARMFUL PATHOGENS
Cockroaches enter buildings in a variety of ways. The ubiquitous German cockroach is often introduced in infested grocery bags, beverage cartons, or furniture. Species such as the American, Oriental, and wood cockroach also gain entry through gaps around windows, doors, vents, and utility openings, and in firewood. In multi-unit dwellings such as apartments, roaches also travel between units through common walls, ceilings, etc. Consequently, while roaches usually thrive where sanitation is poor, even clean homes can become infested.
DESCRIPTION AND HABITS
Cockroaches are flattened, brownish, fast-running insects, with long, slender antennae. There are three life stages: egg, nymph, and adult. The female cockroach produces small, brown, bean-shaped egg cases that are deposited in out-of-the-way places. Several nymphs emerge from each egg case (up to 40 with the German cockroach, 15-20 with other varieties). The nymphs resemble adults except that they are smaller and lack wings. The nymphs gradually become larger and inhabit the same places as the adults. Cockroaches are prolific breeders. Species such as the German cockroach are capable of producing several thousand offspring in less than a year.
Cockroaches do not live in centralized nests or colonies like ants, bees, and termites. However, cockroaches do congregate in distinct areas, in response to aggregating odors in their feces. The droppings appear as pepper-like specks in areas of current or former activity. The spotting is similar in appearance to that of bed bugs, but can usually be distinguished by location, or by other signs of infestation.
Cockroaches are more active at night than during the daytime. During the day, they generally remain hidden in cracks and other dark, secluded areas. At night, they leave their hiding places and search for food. Cockroaches will eat all human foods, plus many other items such as soap, toothpaste, glue, hair, excrement, and filth.
In order to eliminate cockroaches, it helps to know where they are hiding. Preferred locations include warm, dark, moist areas, especially in kitchens and bathrooms. However, depending on the species and extent of infestation, cockroaches may be found anywhere in the home.
Cockroaches can be major pests in restaurants, hospitals, warehouses, offices and buildings with food-handling areas. They secrete a substance which can stain surfaces and produce bad odors. They can also destroy fabric and paper products.
Cockroach prefers to live in damp but warm places and generally found in kitchens, hotels, bakeries, restaurants, warehouses, grocer’s shops, sewage, ships and public latrines, etc., where plenty of food is available. It is a nocturnal animal hiding in holes and crevices during the day and coming out at night when it tastes diverse objects like clothes, shoes, books and human food to feed upon.
Thus, it is omnivorous in diet. It is a fast runner, i.e., cursorial in habit. It can also fly but it flies very rarely. It is dioecious and oviparous and exhibits parental care.
Cockroaches are found in a continuum of dark, humid, poorly ventilated, and often cramped spaces either continuously or when sheltering during their non-active period. Although certain species may be associated with a particular crevice type like the voids beneath rocks or the space beneath loose bark, others are commonly found in more than one of these habitat subdivisions. Many species exploit the interconnectivity of dark, enclosed spaces wherever there is suitable food and moisture, and a distinctive classification of cockroaches as either obligate or facultative inhabitants of caves, litter, or soils is not always a natural one.
HOW TO IDENTIFY COCKROACHES
Four kinds of cockroaches can infest homes in Kenya:
Only a small percentage of the actual number of cockroaches in a house, are seen. Correct identification of cockroaches is important as there are many insects that look similar e.g. long-horned beetles, crickets, leaf-footed bugs and ground beetles.
A cockroach has a flattened, oval body and long antennae about the length of their body.
When looking at a cockroach from above, its head is hidden from view.
It has six strong legs covered with spines.
Many adult cockroaches have fully developed wings, but only few fly.
Young, immature cockroaches resemble adults but are smaller and do not have wings.
LIFE CYCLE OF COCKROACHES
A cockroach has three stages during its life cycle: egg, nymph and adult.
Adults lay eggs contained within dark-colored egg cases size and shape of a dry kidney bean.
Depending on the species, an egg case contains between 16 – 50 eggs.
Eggs hatch into young cockroaches called nymphs, that are more numerous than adults.
HOW TO KEEP COCKROACHES OUT OF YOUR HOUSE
Take precautions while moving:
When moving, use boxes and packing material from a place free of cockroaches.
When packing, watch for cockroaches and their egg capsules.
Remove and destroy any that you find.
Take all boxes out of the home at night and store in a place without cockroaches.
If storing boxes overnight in infested buildings, keep them off the floor and away from walls by placing them on chairs or tables.
During winter, you can store boxes in unheated locations such as garages.
In your new home, watch for egg cases and cockroaches that may have survived.
To confirm you have cockroaches:
Place sticky traps so that they are tight against edges, where walls meet floors.
Place traps in areas where cockroaches are likely to occur, such as in cupboards and around refrigerators, stoves, and sinks.
You can reduce the number of cockroaches by getting rid of places they like:
Remove corrugated cardboard boxes, newspapers, bags and other unnecessary clutter.
When storing items, leave space between packages.
Use caulk to seal spaces and cracks where cockroaches hide. Concentrate on areas where cockroach numbers are the highest.
Seal spaces where plumbing or electrical wiring goes through walls with steel wool or other rough material.
Put covers on points where plumbing enters the wall, to restrict movement of cockroaches.
KEEP YOUR HOME CLEAN
If you limit access to food and water, cockroaches cannot survive and reproduce.
Keep all food stored in a refrigerator or in insect-proof containers made of plastic, metal or glass with tight-fitting covers.
Do not leave pet food and water out overnight.
Wash your dishes, pans and utensils as soon as you are done using them.
Remove all food or spilled drinks from counter tops, and clean counters, sinks and tables with soapy water.
Vacuum floors and all cracks and crevices to remove debris and food.
Take garbage out daily in closed plastic containers. Keep waste containers clean.
Repair any leaky water pipes or faucets.
Recycle cans and bottles on a regular basis.
Wash and clean recycling bins.
Air out and dry out damp places.
TYPES OF COCKROACHES
There are 69 species of cockroaches worldwide, but only a handful infest structures. Knowing which type of cockroach is present will assist you in knowing how to proceed. The common ones include:
German Cockroach or Blattella germanica – This is by far the most common cockroach infesting homes and buildings. The pest thrives in the presence of humans but does not occur outdoors. Adults are light brown and about 1/2 inch long, with two dark stripes running lengthwise along the shield-like area behind the head. The nymphs are smaller and darker with a tan stripe down the middle of the back. German cockroaches reproduce very rapidly, which is one reason why controlling these pests can be difficult. A single mated female can produce thousands of new cockroaches in less than a year.
German cockroaches require warmth, moisture, and food, which is why they are most common in kitchens and bathrooms. Preferred hiding places include cracks and crevices under sinks and toilets; beneath or behind refrigerators, dishwashers, and stoves; near trash containers; and inside cabinets and pantries. German cockroaches also congregate in clocks, toaster ovens, and other heat-producing electronic equipment. When populations are large or food is scarce, they can be found in bedrooms, closets, and other areas of the home. German roaches spend most of their time hidden in cracks and crevices, but can be quite mobile. They often travel between rooms or adjoining apartments via walls, ceilings, pipes, wires and other openings.
American Cockroach the scientific name Periplaneta americana – This is the largest cockroach commonly found within dwellings, measuring about 1 1/2 inches long when fully grown. It is reddish brown to brown, with a pale yellow band around the edge of the area behind the head. Adults have well-developed wings, but seldom fly. The nymphs are smaller and lack wings, but are otherwise similar in appearance. American cockroaches multiply more slowly than German cockroaches (although the smaller numbers tend to be offset by their size).
These cockroaches prefer dark, moist areas, such as in basements and crawl spaces. They often congregate in floor drains, sump pumps, pipe chases, and laundry areas, as well as boiler rooms, steam tunnels, and sewer systems. During warmer months, they can also be found outdoors in yards and around trash containers. American cockroaches often travel long distances from their aggregation sites; long-term relief requires finding and treating these areas.
Oriental Cockroach or Blatta orientalis – The oriental cockroach is shiny black or dark brown, and the adult is about 1 inch long. The females have very short wings, and the males have wings that cover about half the abdomen. This cockroach typically infests cool, dark, damp places such as sewers, crawlspaces, cellars, and basements. The nymphs and adults are relatively sluggish and usually occur at ground level, often living in floor drains and sump pumps. They also live outdoors under stones, debris, and plant litter, gaining entry into buildings via door thresholds, vents, and other openings. Oriental cockroaches are considered especially filthy because they often feed on garbage, human/animal waste, and decaying organic matter.
Brownbanded Cockroach or Supella longipalpa – This species is far less common than the German cockroach, but occasionally can be a problem in homes. Correct identification is important because it has markedly different hiding places and habits. The brownbanded cockroach is similar in size to the German cockroach, but lacks the dark lengthwise stripes on the region behind the head. Instead, there is a black bell-shaped pattern behind the head and two transverse yellowish bands across the wings.
Brown-banded cockroaches can be found anywhere in the home and are often found in rooms other than kitchens and bathrooms. Preferred locations include upper areas of ceilings, walls, cabinets, and closets; behind picture frames and wall decorations; and beneath or inside furniture. This roach attaches its pea-sized egg capsules to hidden surfaces, such as the undersides of dressers and tables.
Wood Cockroaches or Parcoblatta species – Although the usual habitat for these cockroaches is outdoors, they often appear in homes, especially in wooded settings. The adults are about 1 inch long and all stages are brownish in color. In some species, the outer wing margin of the adults is edged in white. Unlike the other cockroaches mentioned, male wood cockroaches are excellent fliers, and both sexes are attracted to lights. Wood cockroaches live outdoors but often find their way into buildings.
These are primarily outdoor cockroaches, living beneath loose bark in woodpiles, fallen logs, and dead trees. They cannot survive indoors, but can be an annoyance during the spring and summer when large numbers wander in from outside. They are also brought into homes during winter in firewood. Large numbers of woods cockroaches are sometimes found nesting in rain gutters and crawl spaces.
Cockroaches are best controlled using a combination of techniques. Since roach’s flourish where food, moisture, and shelter are readily available, cleanliness is an important step in preventing and correcting problems. Spills and food waste should be cleaned up, and unwashed dishes, utensils, and pet food should not be allowed to sit overnight. Loose food should be stored in tight-fitting containers. Garbage should not be allowed to accumulate, and stacks of paper bags, cartons, and newspapers should be discarded or stored in sealed plastic bags.
Outdoor species such as wood cockroaches can be discouraged from entering buildings by installing tight-fitting screens on windows and sweeps beneath doors. Cracks and openings around doors and windows should be caulked. It is also prudent to seal openings where plumbing pipes or wires pass through walls or floors with caulk, foam, or copper mesh. This is especially useful in apartments to reduce migration of cockroaches between adjoining units. Effective control can be:
Although good housekeeping is helpful, insecticides are usually necessary to eliminate infestations, especially of German cockroaches, which are highly prolific. Cockroaches spend little time out in the open; places that are hard to see and reach is where they tend to be. Dark, secluded areas near food, warmth, and moisture are preferred so a bright flashlight helps when performing inspections. Emphasis should be on finding and treating preferred harborage locations, rather than randomly spraying baseboards, countertops and other exposed surfaces. If key harborage areas are missed problems are likely to continue.
Many types of insecticides are available for controlling cockroaches. Most are sold as liquid or aerosol sprays, while some are formulated as edible baits or dusts. Always read and follow product instructions. This will help you to achieve optimal results while using the product safely. Many insecticides require the removal of food and utensils from treated areas. Removing such items often makes areas more accessible for treatment and prevents possible contamination by the insecticide.
Sprays – When using sprays, target the areas where cockroaches prefer to hide. As mentioned previously, this will vary depending upon the species. Be sure to spray any aggregations or areas with fecal spotting. Avoid spraying walls, floors, baseboards and countertops since cockroaches spend very little time in these areas. Any roaches that do happen to traverse these areas are unlikely to remain on treated surfaces long enough to absorb a lethal dose.
Dusts – A few insecticides used for cockroach control are applied as dusts or powders. Most familiar to householders are boric acid and diatomaceous earth. For controlling cockroaches, boric acid tends to be more effective. Roaches succumb to boric acid after crawling over treated surfaces. The tiny particles of powder adhere to the insect’s body, and are ingested as the cockroach preens them from its legs and antennae. Boric acid retains its potency almost indefinitely as long as the dust deposit remains dry.
Insecticide forms of boric acid are sold in bulk cans or a plastic squeeze bottle with a narrow applicator tip. For best results, the dust should be applied as a fine deposit barely visible to the naked eye. Cockroaches tend to avoid heavy accumulations of the powder, much as we would avoid walking through a snowdrift. The easiest way to apply such a small amount is with a ‘bulb’ or ‘bellows’ hand duster sold in hardware stores or online. Key areas to apply boric acid for German cockroaches include crevices along the edges and corners of cabinets; the wall floor junction behind refrigerator, stove, and dishwasher; and puffed into openings where plumbing from sinks, etc. enter walls. Another potential hiding place for German cockroaches is the void (hollow space) under kitchen and bathroom cabinets. This area can be treated by puffing powder through preexisting cracks at the top of the kick panel. Accessing areas behind dishwashers, stoves, etc., may require removal of the front panel.
Never apply boric acid onto countertops or other exposed surfaces, especially those used to prepare food. Traces of powder should be wiped off with a damp cloth. Boric acid should not be injected into electronic equipment as the dust could damage the components.
Baits – Most householders will achieve better results against cockroaches with insecticides formulated as baits. Used correctly, it is possible to achieve results comparable to professional extermination. Cockroach baits contain a slow-acting insecticide combined with a food attractant. Pests find and ingest the bait and crawl away to die. Non-exposed roaches may succumb as well after indirectly ingesting trace amounts of toxicant expelled in the sputum and feces of exposed individuals.
CONTACT OUR PROFESSIONAL COCKROACHES EXTERMINATION
Householders can often eliminate their cockroach problem by following the suggestions outlined in this publication. However, some people may wish to call us as professional to handle the cockroaches issues.
Our cockroaches approach are in different ways. We will perform a limited number of treatments with the option to cancel after the infestation appears eliminated.
Our technician will perform a thorough inspection on each service visit. With specialized insecticides used, its applied into cracks and secluded areas where cockroaches are likely to be living, rather than along baseboards other exposed surfaces. Many of our insecticides formulation we use to control cockroaches remain effective for months. Once an infestation is eliminated, there is seldom a need to do follow up in order to maintain perfect control of these roaches for longer.