School Integrated Pest Management (IPM)
for Cockroaches
Author: Marc L. Fisher, Program assistant, School IPM Training Program and Dini Miller, Ph.D., Assistant professor, Department of Entomology; Virginia Tech
Publication Number 444-511, Posted June 2003
Important Note
According to the Virginia Pesticide Control Act (Section 3.1-249.53), in order to apply ANY pesticide (including Raid®, Round-Up®, and other over-the-counter pesticides) in public areas of ANY educational institution, the applicator must first be certified by the Virginia Department of Agriculture and Consumer Services. It is illegal for uncertified teachers, staff members, administrators, or contractors to apply pesticides on school grounds.
Introduction
Cockroaches are one of the most common urban pests in Virginia public facilities. Cockroaches are pests for several reasons. First of all, cockroaches, in their search for nourishment, invade human food resources. By invading human food and contaminating it with feces and saliva, cockroaches become possible vectors for food-borne illnesses, like Salmonella. In addition, cockroaches stink. Finally, cockroaches have been implicated as a major cause of allergies in children.
Biology and Identification
Cockroaches are flattened insects with long antennae. Their colors may vary but are usually brownish. The cockroach head is hidden from view, tucked under the insect's pronotum. (See Figure 1.) Cockroaches may have wings or be wingless.
Cockroaches experience simple metamorphosis. This means that they pass through three different life stages: egg, nymph, and adult. Nymphs and adults have similar habits and behaviors. Nymphs look like the adults but are smaller and have no wings.
Cockroaches, in general, enjoy living in dark, warm, moist environments. Cockroaches also prefer to be in protected areas. In schools, one may find cockroaches in cracks and crevices in the walls, in cluttered environments, and near drains and leaking pipes. It is rare that a cockroach will be seen in broad daylight, unless large populations of cockroaches are present. Instead, cockroaches become more active at night.
Identifying the correct species of invading cockroach and understanding that particular species' biology is helpful in making correct pest management decisions. Each species varies in its environmental preferences, feeding habits, and reproductive capabilities. The most common cockroaches include the German cockroach, the brown-banded cockroach, the oriental cockroach, the American cockroach, and the wood roach. Use Table 1 to help you identify the type of cockroach with which you are dealing.
Prevention
A population of cockroaches can be kept from infesting a structure by making the structure less hospitable. The goal is to keep cockroaches from reaching the resources they need (food, water, shelter, etc.) The best way to do this is by sanitation and maintenance. This may require time and effort but can be a permanent solution to the problem if done correctly. Below are some of the most effective methods of cockroach prevention using sanitation and maintenance:
- Remove any dependable water source by repairing dripping pipes or leaky faucets.
- Caulk any holes and cracks used by cockroaches as passageways from their shelter to foraging areas.
- Weather-strip around windows and doors where cockroaches may enter.
- Store food in sealed containers (not cardboard boxes) and store food containers in clean dry areas.
- Always keep areas where food is handled clean. Regularly mop, vacuum, sweep, or scrub areas where food is handled.
- Remove all garbage promptly from inside the structure.
- Clean all recyclable materials with soapy water and store outside the structure if possible.
- Keep food containers off the floor.
- Keep clutter to a minimum.
- Limit eating to certain areas of the building. This will keep cockroaches from spreading to other parts of the facility.
Monitoring and Inspection
Detection and monitoring are very important in controlling cockroach populations. Since cockroaches are active at night and hide during the day, it can be difficult to detect their presence and monitor the effectiveness of a control program. By understanding cockroach biology and by utilizing the tools available to you, you can detect their presence and evaluate your control program.
Cockroaches tend to concentrate themselves in areas where water and food resources are readily available. Cockroaches seldom disperse throughout an entire building. Thus, the first step to managing cockroaches is locating areas where high densities of cockroaches exist.
Initial Phase: Locating the Cockroach Problems
You can locate the areas where cockroaches are abundant by using sticky traps as monitoring devices. Place sticky traps at regular intervals (about every 10 to 15 feet) in rooms or areas where you wish to monitor for cockroaches. Traps should be positioned in a way that maximizes the trap's effectiveness. The following suggestions will maximize trap effectiveness:
- Place traps along baseboards, walls, and against the sides of freestanding objects. Cockroaches normally use vertical surfaces as guidelines while they move from place to place. Also, place traps in "drop ceilings," a common area of infestation. Placing sticky traps along cockroach highways will increase your chances at finding areas of high densities. Traps set out in the open away from walls or edges are unlikely to catch cockroaches.
- Place traps near areas where water, food, warmth, and protection are readily available. This may include near sinks, drains, vents, computers, leaky pipes, appliances, food-handling areas, air conditioning units, snack dispensers, dishwashing areas, trash receptacles, bathrooms, and storage areas.
- Place each trap so that it opens parallel to the wall, baseboard, etc.
- Avoid placing traps in extremely dusty areas, as the dust will decrease the stickiness of the trap.
- Try to "think like the cockroach" when deciding where traps will be most effective.
- As traps are placed around the facility, number and date the traps and mark on a map of the facility the placement of each trap. The map of the facility will eventually be the permanent record of your cockroach IPM program. Therefore, it is important that you keep clear, accurate records of your monitoring activities.
Second Phase: Evaluating Trap Counts
After 24 to 48 hours, return to the traps, replace the traps with new ones, and then count and record the number of cockroaches in each trap on the map. It may be necessary to evaluate trap counts over a week or two in order to get an accurate picture of the cockroach infestation. Remember that it is imperative that you keep clear, accurate records of all monitoring and treatment activities. An evaluation of the numbers of cockroaches in each trap can tell you the following:
- Traps with high numbers of cockroaches indicate a problem site. These sites are where you will direct future management efforts.
- Traps with few or no cockroaches indicate a site where management efforts are unnecessary.
- If a trap only contains a few cockroaches (1 or 2 individuals) and no adjacent traps contain cockroaches, this likely indicates that the area does not need to be treated. The trapped individuals are probably stray cockroaches from a larger nearby population.
Third Phase: On-Going Monitoring
After prioritizing areas for treatment and then carrying out treatment activities, you need to determine the efficacy of the treatment. This can also be done using sticky traps. Put out fresh traps a week or so after treatment and count the number of cockroaches 24 to 48 hours later. If the cockroach population has decreased markedly, you have made progress. If not, reevaluate your treatment methods and seek to also eliminate any food, water, or cockroach harborage.
In order to determine the continued success of your management plan and to locate new infestations, continue monitoring for cockroaches on a regular basis throughout your IPM program.
Least Toxic Control Methods
The purpose of integrated pest management (IPM) is to do two things: regulate the pest population and reduce the amount of pesticides needed to accomplish that goal. With the exception of emergency situations, all other available control methods should be used prior to using a pesticide. In addition to the prevention methods outlined earlier, several least toxic methods are available for cockroach control.
Physical Removal
The physical removal of cockroaches is difficult. Cockroaches normally forage at night, thereby limiting a pest control operator's direct access to a cockroach population. Lone cockroaches found during the day may be crushed and then removed from the premises, but the removal of one cockroach will not have much of an impact on the entire population. Vacuums may be used to remove large numbers of cockroaches. Also, sticky traps may be left overnight to trap live cockroaches allowing for their easy removal in the morning. The use of traps to control cockroaches may have some effect on small cockroach problems but may have no effect on larger infestations.
Chemical Management
Sometimes sanitation, maintenance, and physical removal alone may not be enough to control an existing cockroach problem. If cockroaches persist or if an emergency situation warrants immediate control of a cockroach population, chemical pesticides may be needed. Remember that Virginia law requires that all pesticides applied on school grounds must be applied by a certified applicator. All pesticides should be applied according to label directions. Applicators must wear protective clothing. Pesticides should never be applied where they might runoff into storm drains or sanitary sewers.
Whatever the control method you choose, it is imperative that you keep clear, accurate records of all actions taken. Using the same map that you have been using to monitor, record the date of any pesticide application, the formulation and brand name of pesticide used, and where the pesticide was applied.
Below are several different chemically based management options.
- Diatomaceous earth can be placed within cracks and crevices where cockroaches enter the structure. Diatomaceous earth is a dust made up of the fossilized remains of diatoms. The dust adheres to the cockroach's protective cuticle, making the cockroach susceptible to desiccation. Silica aerogel can also be applied for the same purpose. These dusts should only be used in dry areas since moisture reduces their effectiveness.
- Boric acid is a great tool for integrated pest management. The advantages of boric acid include its long-term residual effectiveness and its low toxicity to humans and pets. Boric acid comes in several different formulations, including bait, dust, and aerosol. These formulations are particularly effective when applied in cracks and crevices. Boric acid dusts can also be applied into wall voids where cockroaches are present.
- Insect growth regulators (IGRs) are effective pesticides that are safer than more traditional toxicants. Cockroach IGRs are insect hormone mimics that cause reproductive sterility.
- Cockroach bait is the most common form of chemical management in an IPM setting. Baits are a toxicant that has been combined with a non-toxic food source. Baits reduce the overall amount of pesticides used by allowing for precision placement where they are available to cockroaches but not to people or pets.
Below you will find several important factors to think about when using cockroach baits.
- Place baits near the target cockroach infestation. Cockroaches will not travel long distances away from their shelter in order to forage for food. Therefore, the closer to the infestation you place the bait, the more effective the control will be.
- A small amount of bait placed strategically in many places is more effective than placing large amounts of bait in only a few places.
- Place the bait along edges, in cracks and crevices, and between cockroach harborages and foraging sites.
- Make sure the bait is not placed in areas where it will get covered by grease, flour, or dust. This will render the bait less effective. Use baits placed in plastic stations in these types of environments.
- Check baits regularly to make sure they are still present and working. Baits may at times dry out, become moldy, or get accidentally removed. Replace baits as needed.
- Do not use other types of pesticides around the bait stations (e.g., sprays or dusts). The pesticides may act as a repellent, driving the cockroaches away from the bait.
Record Keeping
Protect yourself against liability. Record all chemicals applied in a pesticide application IPM logbook on the facility's premises. Include the name of the applicator, the date of the application, the formulation used, and the brand name of the chemical used. Also be sure to document the location of application and the pest problem that initiated the chemical treatment.
INTEGRATED PEST MANAGEMENT (IPM) TECHNIQUES
The Four-Step Plan
- Prevention
- Monitoring and Inspection
- Least Toxic
Control Methods
- Record Keeping
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