IPM for Cockroaches in Schools


Cockroaches are the most important pest in schools, homes, restaurants, and other indoor spaces. They consume human foods and contaminate them with saliva and excrement. Infested buildings are easily detected by a characteristic fetid odor that is produced by the cockroach bodies and fecal material. Additionally, cockroach feces and cast skins contain allergens. The allergens can become airborne and cause allergic reactions, asthma and other bronchial problems in persons inhabiting infested buildings.

Cockroach and Biology

Except for size and markings, all cockroaches are similar in overall appearance: flattened, oval shaped insects with long legs and antennae. The most common pest cockroaches in the United States can be divided into two groups: domestic-small cockroaches that only live in human structures and peridomestic- larger cockroaches that generally live outdoors but occasionally invade structures. The most common domestic cockroach pests are the German and brownbanded cockroaches. The most common peridomestic cockroaches in the United States are the American, brown, smokybrown and oriental cockroaches. A Table is available that lists their important characteristics.

The Asian cockroach (Blattella asahinai) has recently become established in Florida. This species looks identical to the German cockroach but lives exclusively outdoors and flies readily. Because of its great reproductive potential it has already become a significant pest in gardens, lawns, landscaping, groves and agricultural areas.

In general, cockroaches like to squeeze into warm cracks and crevices, but as you can see from the Table, the specifics of their habitat differs with the species of cockroach. The German cockroaches prefer moist kitchen and bath room areas while brownbanded cockroaches are most often found in the dryer living and bedroom areas. Additionally, American and oriental cockroaches are generally found in very high moisture habitats (sewers, basements, mulch etc). However, smokybrown cockroaches are more often found in dryer areas like treeholes and attics.

The life cycle of the cockroach begins with the egg case, or ootheca. In German and Asian cockroaches the female carries the egg case around with her until just before the eggs hatch. The brownbanded and peridomestic cockroaches deposit the egg case in a sheltered place (see Table). Cockroaches undergo a gradual metamorphosis in their life cycle. An immature cockroach, or nymph, looks very much like an adult, but is smaller and wingless. As the nymph grows, it sheds its skin (molts) a number of times. The time it takes a cockroach to develop is influenced to some degree by temperature. The nymphal cockroaches develop more rapidly when it is warm. Thus populations of cockroaches can become extremely large during the summer months.

Cockroaches prefer carbohydrates to protein and fat. They will discriminate among foods if given a choice, but when hungry they eat almost anything. Some products not normally considered food -- starch-based paints, wallpaper paste, envelope glue, and bar soaps --contain carbohydrates, and hence are food for cockroaches.

Cockroaches are generally active at night and remain hidden during daylight. Daylight sightings usually indicate a large population which has overrun available harborage, or a recent emigrant cockroach is seeking shelter.


Cockroaches have not yet been proven to be involved in the natural transmission of any particular human pathogen (this means that they are not a necessary part of the life cycle of a disease organism or documented as the cause of any disease outbreak), however, evidence has been collected that clearly indicates that cockroaches can mechanically transmit a long list of disease-causing organisms. Because cockroaches wander at will through all types of organic wastes, then travel over kitchen counters, cooking utensils, food, plates, and silverware, their presence indicates potential contamination of foods and utensils. However, the most important health issue associated with cockroaches is the production of allergens which can cause severe bronchial problems in sensitive individuals and children.

Inspection and Monitoring

Efforts to control cockroaches should begin with a thorough visual inspection and a continuous monitoring program. Cockroaches are rarely dispersed everywhere throughout the building. Once they have located a suitable harborage, they tend to concentrate there, leaving periodically to forage for food and water, then returning to the same place. Thus, the first step in the visual inspection is to locate potential cockroach harborage sites. This should be followed by monitoring the area to locate specific cockroach concentrations. Monitoring of infestation sites must continue after treatment to determine whether control efforts have satisfactorily reduced the cockroach population.

Visual Inspection

How and Where to Inspect

When inspecting for cockroaches, define the specific area on your map that is to be inspected. Inspect the entire area in a systematic and logical fashion from floor to ceiling to make sure no potential harborage areas will be overlooked. Be sure to inspect:

When to Inspect

Most inspections are conducted during daylight hours for the convenience of the inspector. However, since cockroaches tend to remain hidden during the day it is difficult to access the size and location of the population until after dark. Therefore, be sure to schedule at least one inspection after dark when the majority of the population is active. This will give you more information about where the cockroaches are and the level of sanitation at a time when the building is supposed to be clean. Begin your inspection with the lights off if possible. A flashlight covered with a yellow filter (Roscoe #12) will prevent the cockroaches from being disturbed while you look for their harborages and sources of food and water. Then turn on the lights and examine areas where cockroaches were observed. Note this information on your map.


Flushing is a method of locating cockroach harborages that are difficult to see or reach. Usually a repellent pyrethroid insecticide is sprayed into a suspicious crack or crevice to drive out cockroaches. There are several disadvantages to flushing, first it displaces the cockroaches causing them to scatter and possibly disturb employees in the area, also it makes the harborage repellent so that cockroaches will not return to it before treatment.

Flushing should not be necessary, especially if you conduct thorough inspections and include at least one night inspection. However, if you do encounter situations where flushing is necessary you can use pressurized air (available in an aerosol can) or a hair dryer. In this way scattered cockroaches will soon return to the harborage where they can be monitored and treated.

Monitoring with Sticky Traps

A visual inspection may not provide all the information you need about where cockroaches are harboring or how many cockroaches there are; you may need to use sticky traps as well. Many brands of sticky traps are available, but most are of a similar design -- a rectangular or triangular cardboard box with bands of sticky glue inside and, in some models, a dark strip of cockroach attractant.

The best sites for traps are near harborages and along cockroach travel routes. Cockroaches may not find traps in open locations or outside their normal routes of travel. Initially, it is best to put out traps at all suspected harborages, water resources and travel routes. However, avoid placing traps in extremely dusty or moist areas because they will quickly lose their stickiness.

The more traps used, the sooner the concentrations of cockroaches can be located. Later, you can use fewer traps for ongoing monitoring. Try to "think like a cockroach" as you decide where to place the traps. Your monitoring map and the following examples will help you to determine the best spots.

Trap Locations

Keeping in mind the habitats preferred by cockroaches (refer to Table), place the traps in the following types of locations:

Trap Placement

Cockroaches are thigmotropic which means they like to travel along edges where vertical and horizontal surfaces intersect (i.e.: where the floor and wall come together). So it is important that traps be placed flush against the vertical surface or the cockroaches may continue to travel behind the trap without ever entering it. Examples of edge intersections include:

Number and date each trap before you put them out. At the time of placement, mark trap location on your monitoring map. After 24 to 48 hours, pick up the traps, then count and record the number of cockroaches in each trap. Record the date and the number of cockroaches on the monitoring form.

Evaluating Trap Counts

Use the trap counts located on your map to pin-point sites of infestation.

Post Treatment Monitoring to Evaluate Efficacy

After the initial monitoring to pin-point sites of infestation, treatment efforts can be concentrated at these locations. A week or two after treatment, monitors should again be placed at the infestation sites to see how well the treatment efforts are working. Place fresh traps at the locations indicated on your map and count the number of cockroaches in the traps after 24 hours. If the trap catch has dropped considerably the cockroach population has declined and progress has been made. If not, another treatment strategy should be considered and greater efforts must be made to eliminate food, water and harborage resources. In order to assess the continued success of treatments and detect any new infestations, continue to monitor after the IPM program is underway. Vigilance is important and good record keeping will save time and energy.

Continuous Monitoring

To avoid future infestations monitoring should be continued on a monthly or quarterly basis. This will alert pest control personnel to a new invasion before a population can become established. Cafeterias and other food-handling locations should be monitored at least once a month because of the constant transport of food and packaging (that may contain cockroaches) in and out of these areas.

Establishing a Communication System

A successful monitoring program depends on clear and frequent communication with principles, teachers, custodians, and food service personnel. These people have first-hand knowledge of pest sightings, sanitation problems and other contributing factors, as well as the history of control measures in their buildings. With a small investment in time, school personnel can be trained to serve as additional sources of valuable information for the monitoring program.

Make sure personnel understand the following:

Management Options


Food service and custodial staff play an essential part of any successful cockroach management program. Provide them with information on how to maintain cockroach-free kitchens, dining rooms, and waste disposal areas by applying the methods described below. Teachers, students, and other staff also play a significant role in maintaining a high level of sanitation in other areas of the school, so they must be informed of their responsibilities in that regard.

Habitat Modification

Cockroaches need food, water, and harborage to survive. By modifying the environment of an infested building, you can reduce cockroach access to these resources. A few well placed alterations will produce a long-term reduction in the capacity of the structure to support cockroaches. It is important to note that the simple act of limiting food, water and harborage resources will dramatically reduce the number of cockroaches an environment can support.

Limiting Areas for Eating

If you expect to contain and limit pest problems (ants and rodents as well as cockroaches), it is very important to designate appropriate areas for eating and to enforce these rules. The fewer designated areas, the easier it will be to limit the pests.

Proper Food Storage

Eliminating Water Sources

German cockroaches can survive for a couple of weeks without food but they must have regular access to moisture or they will die within a few days. Cockroaches find drinking water in:

Much can be done to limit this supply by increasing sanitation and making repairs. Clean up spills and dispose of drink containers immediately after use. Keep aquariums and terrariums sealed with tight fitting screened lids. Repair leaks and dripping faucets then drain or ventilate moist areas. Kitchen surfaces should be kept dry when they are not in use, especially overnight.

Eliminating Cracks and Crevices

Eliminating Clutter

Clutter creates a complex environment that provides a multitude of harborages in which cockroaches can live and breed. The removal of clutter is one of the most important components of cockroach management. All useless, idle or outdated items should be removed from the premises. Also, the need for in-house storage of food products and paper goods should be kept to a minimum.

Installing Cockroach-proof Fixtures and Appliances

Whenever food preparation areas are scheduled for remodeling, the school district can take the opportunity to install cockroach-proof kitchen appliances and fixtures, such as stainless-steel open shelving units. The round shape of the metal and the general openness of the design offer few hiding places for cockroaches. Free-standing storage units and appliances on castors enable them to be rolled away from walls to facilitate thorough cleaning.

Removing Vegetation

Peridomestic cockroaches live primarily outdoors in tree holes, mulch or vegetation. In cases where these cockroaches periodically invade the school buildings, it may be necessary to remove planter boxes, mulch, vegetation or other landscaping in the adjacent area.


Sanitation disrupts and eliminates cockroach resources. This disruption of the environment can play a significant role in slowing cockroach population growth. Sanitation creates an additional advantage by making the cockroach environment so barren that they have a much greater chance of contacting toxic baits or insecticidal dusts (see Chemical Controls below).

Thorough daily cleaning is essential:

Although sanitation does much to prevent and curb cockroach infestation, an existing population cannot not be controlled by sanitation alone.

Physical Controls

Mechanical Barriers

Peridomestic cockroaches can travel up the outside of the buildings and enter through open windows, weep holes, or ventilation ducts. Screening these openings will prevent cockroaches from using these entry points. Screens can also be placed behind grill covers, over vents and floor drains to prevent cockroach entry. Use caulk around the edges of the screen material to make a complete seal.

Domestic and peridomestic cockroaches can travel within and between buildings on runways formed by electrical conduits, heating ducts and plumbing pipes. Seal openings around these runways with caulk, steel wool or screening material.


A strong vacuum can be used to pick up live cockroaches as well as their egg cases and droppings. If the vacuum is capable of filtering out very small particles (0.3 microns), it will greatly reduce the amount of cockroach debris that can become airborne during cleaning. Airborne cockroach debris (fecal material, body parts and cast skins) can cause allergic reactions in sensitive people.

If the cockroach population is large, vacuuming is a quick way of reducing the population immediately. Once a large portion of the population has been eliminated it is much easier to effect the remaining cockroaches with your treatment measures.


In certain limited situations traps can be used to reduce cockroach numbers. Traps should be placed near suspected harborages and water sources but removed after a few days or they may begin to smell. Although traps will often capture a number of cockroaches they will very rarely, if ever, achieve a significant degree of control.

Chemical Controls

If non-chemical methods alone prove insufficient to solve the problem, then integrating a pesticide into your management program may be warranted.

Pesticides must be used in accordance with their EPA-approved label directions. Applicators must be certified to apply pesticides and should always wear protective gear during applications. All labels and Material Safety Data Sheets (MSDS) for the pesticide products authorized for use in the IPM program should be maintained on file. Do not apply these materials when buildings are occupied, and never apply them where they might wash into the sewer, storm drains or any body of water.

When insecticides are needed, they should be applied as crack and crevice treatments or in a bait formulation. Broadcast spraying of insecticides greatly increases exposure risk and can lead to cockroach resistance when the pesticide residual activity begins to decline and cockroaches are exposed to sublethal doses. Note: Do not use spray formulation insecticides around computers where they may short-circuit the equipment. Plastic bait stations can be placed in and around computer equipment if cockroaches establish a harborage inside.

Control Strategies

The most recent technological advances in cockroach control have been in bait formulations, and insect growth regulators. Other currently used products include desiccating dusts. Each of these treatment methods will be discussed in detail including how they may be incorporated into a complete integrated cockroach management program.

Cockroach Baiting

Cockroach baits consist of a toxicant mixed with a food source. Some baits also contain attractants or feeding stimulants that are supposed to make the bait more attractive to cockroaches than the other food sources that may be available in the immediate area.

Current indoor bait formulations are applied as bait stations, gels, dusts or pastes. The bait station is one of the more popular application methods for educational facilities. This is because the stations are easy to put out, they are safe around children and animals and have residual activity. Gel and dust bait formulations are also very safe and are packaged for injection into cracks and crevices which are not easily accessible. Until recently, paste baits were very messy and required application with a putty knife. However, manufactures have improved these products by repackaging the bait material into plastic syringes that are also suitable for bait gun application. This greatly improves bait placement allowing paste baits to be applied into cockroach harborages like the gel and dust formulations.

Almost all baiting products available for indoor use are formulated using one of the following active ingredients: fipronil (Maxforce/Combat); hydramethylnon (Seige); chlorpyrifos (Raid Max; Ortho); or abamectin (Avert). Combat/ Maxforce are bait products using injectable gel formulations and the bait station delivery system. Siege bait is available as an injectable gel in a syringe and bait gun. Raid Max is available as a bait station. Ortho is a granular formulation for use outdoors. Avert is available as a bait station, a gel aerosol and a flowable bait dust that can be injected into cracks and crevices.

Domestic Cockroach Baiting

Peridomestic Cockroach Baiting

Outdoor baiting products are used primarily for the control of peridomestic cockroaches. Spreadable granular baits containing chlorpyrifos or bait stations with hydramethylnon bait are the most common formulations used for peridomestic cockroach control. Spreadable baits are usually applied as a perimeter band around a structure. It is difficult to determine the residual longevity of these products particularly in areas where precipitation is frequent. Even "weatherized" baits have difficulty retaining their residual properties where there is heavy rainfall. This is particularly true in the southeastern United States where precipitation can ruin bait effectiveness within a single day. Bait stations for peridomestic cockroaches are simply larger versions of those used for German cockroach baiting. The problem with this baiting system is that peridomestic species live and breed in outdoors in palm trees, tree holes and other areas where bait stations are not suitable. The large bait stations can be used to capture peridomestic cockroaches caught foraging inside, but this does nothing about the population of cockroaches that continues to breed outdoors.

Insect Growth Regulators (IGRs)

Insect Growth Regulators (IGRs) are a group of compounds which disrupt the normal growth and development of insects. The IGRs are very safe compounds. They generally have very little toxicity to mammals because they act by disrupting the hormonal processes that are specific to insects.

IGRs that mimic the juvenile hormones of cockroaches (and other insects) are called juvenile hormone analogues (JHAs). JHAs are chemical compounds whose structure is very similar to the hormones that immature cockroach produces naturally. These hormones function in cockroaches roughly the same way as they do in humans. They send chemical messages throughout the body that regulate physiological changes. These changes facilitate the development of a juvenile into a reproductive adult. Juvenile hormone analogues disrupt this natural process. Specifically, JHAs interfere with the proper development of last instar cockroach nymphs. Instead of the nymphs molting into reproductive adults they molt into "adultoids", which often have twisted wings and are sterile. As more and more cockroaches are exposed to the JHA, the adultoids begin to predominate. Because the adultoids are unable to reproduce, over time, the cockroach populations begins to decline. JHAs are a very effective method of long term German cockroach control. However, because JHAs eliminate reproduction, but do not kill existing cockroaches, they are very slow acting taking from four to nine months to achieve control. It is for this reason that JHAs are often combined with residual insecticides. In this way most of the population is eliminated by the insecticide yet immature cockroaches that survive are sterilized by the JHA.

Insect Growth Regulators are available in spray formulations or point source dispensers (where the IGR is released on a filter paper contained in a permeable plastic station then transmigrates throughout the infested area). Hydroprene (Gentrol Point Source) is a JHA that is currently available for indoor cockroach control and is labeled for use in kitchens and food preparation areas. Pyriproxifen (Nylar, spray formulation) recently joined the market, but is not labeled for use in kitchens. At this time there are no IGRs available for peridomestic cockroach control.

Inorganic Dusts

Inorganic dusts, such as silica gel and boric acid, have been used frequently for indoor cockroach control. These dusts can be applied with a squeeze-bulb duster into cracks and crevices under sinks, stoves, behind refrigerators, along baseboards, in electrical outlets, cabinets and wall voids. Silica gel is simply finely ground sand or glass that adheres to and absorbs the protective waxes on the cockroach cuticle resulting in cockroach death from dehydration. Boric acid is a stomach poison that is picked up by cockroaches walking across dusted areas. The boric acid adheres to the cockroach cuticle so when the cockroach grooms itself it ingests the boric acid and soon dies.


German cockroaches are the most important pest in the indoor environment. Peridomestic cockroaches live primarily outdoors but often invade structures looking for food, warmth or moisture. The treatment measures for indoor versus outdoor cockroaches is very different so it is extremely important that a problem cockroach population be correctly identified. Once the cockroach and its habitat have been determined, the magnitude and location of the population needs to be evaluated. This can be done by performing a thorough inspection in and around the structure and monitoring with traps. The population information should then be used to choose treatment strategies. A combination of treatments is recommended for a complete approach to cockroach management. Several least toxic treatment choices are available for cockroach control, they include bait products (available for indoor and outdoor use), insect growth regulators (IGRs), inorganic dusts and traps.

Sample IPM Programs

Cockroach Infestation in a Kitchen
Cockroach Infestation in an Office or Classroom

Edited by: Dr. Dini Miller, Urban Pest Management, Virginia Polytechnic Institute and State University;
Originally written by: S. Darr, T. Drlik, H. Olkowski, and W. Olkowski.

Photographs: University of Florida

Published: March, 1998