Preventive Practices Work Best to Control Cockroaches


(Beyond Pesticides, June 24, 2009)

An analysis of the New York City Public Housing system’s pest management practices finds that a combination of preventive management practices and least toxic pesticide options are more effective than conventional chemical-dependent practices. The analysis finds that integrated pest management (IPM)practices with a focus on sealing cracks and proper sanitation, coupled with boric acid controls cockroaches better than chemical approaches.

The study, entitled “Effectiveness of an Integrated Pest Management Intervention in Controlling Cockroaches, Mice and Allergens in New York City Public Housing,” finds that apartments utilizing integrated pest management (IPM) measures have significantly lower counts of cockroaches at three months and greater success in reducing or sustaining low counts of cockroaches at three (75 percent decline) and six months (88 percent decline). IPM was associated with a more than 50 percent drop in cockroach allergen levels in kitchens at three months, and in beds and kitchens at six months. In contrast, the number of cockroaches in buildings receiving professional exterminator visits every three to six months increased slightly. Pesticide use was reduced in apartments using IPM relative to apartments with chemical practices in place. Residents of IPM apartments also rated building services more positively. The researchers also found that that an easily replicable single IPM visit was more effective than the regular application of pesticides alone in managing pests.

According to the researchers, the New York City Housing Authority (NYCHA) is the largest public housing owner in North America with more than 405,000 low-income residents. A successful implementation of IPM in an institution of this size is thought to offer many potential benefits such as pesticide use reduction, improved pest management and reduced pest and allergen burdens in housing populated by largely Black and Hispanic families with disproportionately high prevalence of asthma- which is mostly attributed to pest allergens.

In the study, 323 apartments were evaluated. The practices include mechanical and steam cleaning using soap on kitchen cabinets, stoves, refrigerators, floors and countertops, and bathroom floors and fixtures. Practices also include the use of latex caulk to seal cracks and crevices, gaps within kitchen cabinets and between the cabinets and wall, gaps and cracks in baseboards, plumbing joints, and other potential ports of entry for pests; and boric acid and cockroach baits were applied. Apartment residents were instructed to store open food in sealed containers, cover garbage containers with a tight-fitting lid, and dispose of garbage frequently. Residents were also provided with a covered garbage container, food storage containers and cleaning supplies, including sponges, soap, powdered cleanser, and degreasing solution. Residents were also instructed not to use aerosol/spray pesticides for the duration of the study. No repeat IPM visits were scheduled. Cockroach populations were monitored with pheromone glue traps, three and six months later.

This study is the first to show that a single, short, low-cost visit by housing authority workers to address the underlying source of pests can be more effective at controlling cockroaches and their allergens in buildings than repeated professional pesticide applications. However, other studies also found that IPM techniques are effective, especially in the long-term, against pests.

Source: University of California, Berkeley