Cockroach control usually relies on insecticides, but repeated use of the same insecticide often results in resistance and makes any further control with insecticides more difficult.
    Auburn University scientists, led by Arthur G. Appel, developed and validated an IPM system to manage smokybrown cockroaches without using large volumes of insecticide.
    Another project was to develop a tactic for cockroach control that did not use an insecticide but instead forced cockroaches out of their preferred but difficult-to-treat resting areas.
 

Controlling More with Less

Smokybrown cockroaches, Periplaneta fuliginosa (Serville), are the most important outdoor cockroach pest in the Southeast. Homeowners, county Extension agents, and professional pest control personnel have continually battled this pest, with limited success.
    The standard recommendation for smokybrown cockroach control has been to spray a 10-foot barrier of insecticide around an affected home. Not only are these barrier treatments marginally effective, but they can require as much as 100 gallons of insecticide.
    Population size and distribution of the smokybrown cockroach was evaluated by trapping the pest around foundations of homes and at trees, bushes, outbuildings, and mulched areas at more than 100 residential properties in central Alabama.
    The researchers then developed a mathematical model that relates cockroach population size to house and landscape characteristics.
    The Auburn IPM system consists of cultural,physical,and limited chemical tactics based on the most important characteristics of the model:

Cultural tactics in the system include:

• removing large objects from near the home
• tightly covering trash cans
• removing pet feces and any ripe fruit or vegetables from the property taking up pet food overnight
• watering yards in the morning rather than evening

• replacing worn vent and window screening
• caulking cracks
• filling in tree holes

• placing low toxicity insecticide baits in heavily mulched areas, in outbuildings, and in areas where cockroaches have been seen
• applying insecticide sprays only at points of entry into the structure- around vents, windows, and doors, for example.

Moving Air an IPM Approach

Moving air has been used to exclude house flies and other insects from entrances of food-processing plants and storage facilities. Auburn scientists theorized it also could move cockroaches out of hiding places and toward insecticide to reduce the amount of insecticide required.      An electric version of the classic Ebeling choice box was developed to test the repellency of moving air.The box consisted of two parallel plastic pipes with an access hole between them. One pipe was painted blackand equipped with a fan and restrictor plate for adjusting air flow between 0 and 4.75 meters per second. (Household forced air conditioning and heating systems produce air velocities of 4 to 5 meters per second at the vent register.)

Electric choice box used to test repellency of moving air.

    The other pipe, a clear plastic,was supplied with a piece of dry dog food and a cotton water wick. Cockroaches could choose to enter the dark pipe (where they would normally hide) and be exposed to an air flow or to remain in the light and in still air.

Tested were:

• the German cockroach, Blattella germanica (L.), the most important indoor cockroach pest
• the American cockroach, Periplaneta americana (L.), the most important sewer pest
• the smokybrown cockroach, P. fuliginosa (Serville).

Other implications of the study:

• If cockroach populations can be moved out of preferred resting areas,they also might be directed to insecticidal baits placed on the bottom of cabinets and beneath stoves and refrigerators.
• If air flow could be increased in sewer systems and around duct work in buildings, American and smokybrown cockroaches could be displaced and guided toward insecticide deposits.
• If air flow repelled cockroaches from sheltered locations and directed them to areas that do not support population growth, it could prevent infestations.