The stuff of urban legends, cockroach infestations are among those that homeowners fear the most. And they should. Not only are cockroaches extremely difficult to control, they're one of the leading causes of allergies, asthma, and other bronchial disorders. They can also carry bacteria and other disease organisms on their bodies and in their fecal matter.
There are about 3,500 species of cockroaches in the world. Of them, only a handful are considered major pests. They all like high humidity and high temperatures, and they tend to hang out in cellars, crawl spaces, and around kitchen and bathroom plumbing.
Food, water, and a safe place to hang out are all cockroaches need to be happy. Denying them these things plays a big role in controlling their numbers.
IPM controls for cockroaches include keeping them out of structures and eliminating their food, water, and hiding places.
Other IPM controls for cockroaches include trapping. Sticky traps for cockroaches are widely available. Put them everywhere cockroaches could hangout, including garbage storage areas, under sinks, in the bathroom, in cabinets, and under and behind refrigerators.
You can make a cheap and effective cockroach trap out of an empty jar and some petroleum jelly. Any jar with a rounded inside lip will work. Coat the inner lip of the jar with the petroleum jelly. Then place a piece of bait — beer-soaked bread, dog food, apples, you name it — in the jar. Wrap a paper towel around the outside of the jar to give the critters something to grab onto, and place the traps in high-risk areas. The petroleum jelly will keep the roaches from climbing back out once they're in.
To kill trapped roaches, pour dish detergent into the jar and add hot water. Dump the contents outside or in the garbage. Wash out the jar and repeat the process every two to three days.
Two natural substances — diatomaceous earth (discussed in Bedbugs) and boric acid — are often recommended for indoor cockroach control. Boric acid is a stomach poison that cockroaches pick up when they walk over dusted areas. When they groom themselves, they eat the acid and eventually die. Apply either product lightly with a squeeze-bulb duster everywhere you've seen cockroach activity — in cracks and crevices under sinks, behind fridges and stoves, along baseboards, in electrical outlets, and in cabinet and wall voids.
IPM is the most effective approach for cockroach control. Insecticides should not be used alone as cockroaches easily become resistant to them. Many over-the-counter formulations are available. If you go this route, using products from different insecticide classes might help prevent resistance.
Inside, apply insecticides to cracks and crevices where cockroaches live. Outside, treat along foundation walls with products labeled for outdoor control.
Roach baits are an effective control and are widely available as gels, granules, pastes,and dusts. Again, rotating products between insecticide classes can help prevent resistance.
Insect growth regulators, which attack infestations by disrupting insect reproduction cycles, are an excellent control, especially when paired with baits.