As a result, insecticides that at one time controlled a largely susceptible population are no longer effective against the remaining altered population and most of its descendants. Some German cockroaches in apartment buildings have been found resistant to certain carbamate, organophosphate, chlorinated hydrocarbon and pyrethroid insecticides. For example, in the first month use an organophosphate, the second month use a carbamate, the third month use silica gel, the fourth month boric acid and the fifth month resmethrin. By using insecticides that attack the insect at different points in its body, the insect's defense system is overwhelmed. For example, selection with Baygon induces the same resistance spectrum as diazinon.
Insecticides Apply chemicals at roach hiding places.
Enter a dark room quietly, turn on the light, and watch where the roaches run. Spot treat these hiding places and known pathways, especially under and behind loose baseboards or molding strips and around pipes or conduits along the walls and through them. Do not treat entire floors, walls or ceilings. Roaches may hide around the kitchen sink or drain board, in cracks underneath cupboards and cabinets, inside the motor compartment of mechanical refrigerators, behind window and door frames, in radio and TV cabinets, and around closet and bookcase shelves. Surfaces where food is prepared should not be treated.