Least of Toxic Methods for Cockroach Control

Controlling a cockroach infestation is not simply a matter of aesthetics. Large indoor cockroach populations are one of the leading causes of allergies, asthma and other bronchial disorders in humans. Additionally, cockroaches are capable of carrying disease organisms and bacteria on their bodies and in their fecal material. The presence of cockroach populations in and around urban structures is an indication that cockroach food, moisture and harborage resources are present. These conditions allow pests to proliferate and lead to cockroach population explosions.

Until recently, efforts to suppress cockroach populations in the urban environment have relied almost exclusively on repeated applications of synthetic pesticides. Surveys have shown that more than 1/3 of all the pesticides used in the U.S. are applied in urban environments and most of these pesticides are applied in the home. However, the chemical approach to cockroach control has become increasingly less popular. This is primarily due to the development of multi-chemical resistance among German cockroach populations and increased public conce
about pesticide exposure in their living environment. These two issues have greatly emphasized the need for a more holistic and less toxic approach to cockroach management.
The Principle Cockroach Pest Species

In order to deal with any particular infestation it is important that the cockroach pest be properly identified so that most appropriate and least toxic control methods can be applied. There are 41 cockroach species present in the state of Florida, of these only about 6 are considered pests. These pest species can have very distinct behavior and habitat preferences.

The predominant pest cockroach species in Florida (and the world) is the German cockroach, Blattella germanica (Figure 1). German cockroaches are small with adults less than 0.75" (1.5 cm) in length. They are gold in color and have 2 dark longitudinal bands on their pronotum near the head. Immature German cockroaches, or nymphs, are smaller than adults, wingless and dark brown in color. German cockroaches are primarily indoor pests. They have strict moisture requirements so they are usually found in kitchen and bathroom areas. Adults live about 6 months, and during this time the female produces from 4-8 egg cases (oothecae). The female carries the egg case throughout embryonic development (3-4 weeks) often releasing it from her body only hours before the nymphs hatch. Each female produces an average of 28 nymphs from each egg case. German cockroaches are the most prolific pest species and therefore the most difficult to control.

Cockroach Prevention: Exclusion and Sanitation by

D. M. Miller and P. G. Koehler2

Long term prevention of cockroach infestation is the best means of ensuring a cockroach free environment. This is most easily accomplished by means of exclusion (preventing cockroach entry) and sanitation (elimination of cockroach resources). Not only will these measures prevent a future infestation, they will also help to reduce an existing cockroach problem.
Exclusion

Prevent cockroach entry:

Cockroaches migrate easily through multi-unit dwellings via plumbing and electrical connections. Sealing gaps around plumbing, wall outlets and switch plates will prevent cockroaches from migrating from infested units to others.

Keep doors and windows closed and screened. Also, caulk cracks and gaps that may allow peridomestic cockroaches to invade from outdoors.

Peridomestic cockroaches frequently enter homes by coming up through dry drain traps. Periodically run the water in spare bathrooms, utility tubs and toilets to keep the drain trap filled and off limits to cockroaches.

Fiberglass window screen over vent pipes on the roof will prevent cockroaches from migrating up from sewer connections and gaining access to attics and windows.

Groceries, produce and other packaged food products may have been stored in infested locations before they were purchased. Make an effort to visibly scan all grocery items for cockroach evidence before putting them away.

Children can transport cockroaches from school to home in book bags and lunch pails. Inspect these items on a regular basis.

Guests (adults and children) can often transport cockroaches from their infested home to yours either on themselves or in packages. Limit guest access to specific areas of your home and inspect these areas after they depart.