For the past several years, many researchers have been carrying out studies concerning the association between common cockroach pests and the presence of indoor allergens that contribute to the development of asthma in children. While it has long been known that cockroach pests serve as mechanical disease vectors, the scientific evidence showing that indoor roaches may have contributed to a significant amount of existing childhood asthma cases has made them the most medically significant of all insect pests commonly found within homes.

Any home that has ever been infested with cockroach pests contains roach allergens, as the pests establish harborages in inaccessible indoor areas that cannot be readily sanitized. These areas include wall voids, subfloors, and ceiling voids. In order to clear a home of cockroach allergens, all past roach harborages must be sanitized, but the five species known for contributing to allergy sensitization habitually infest different indoor areas. Therefore, it is important for residents to know where each of these species prefers to nest within homes, and what sort of conditions allow them to thrive.

Cockroach excrement, body fragments, eggs and shed skins from past and/or current infestations are present in dust and inhaled within homes, resulting in the progressive sensitization to cockroach allergens. The German and brown-banded cockroaches are the only two roach species in the country that naturally dwell in structures, but their infestation behaviors differ markedly. For example, German cockroaches, which can be found throughout the US, generally congregate within dark and humid indoor areas where the temperature is around 69 degrees. These roaches are often found nesting near heaters, within laundry rooms and bathrooms, below appliances, and especially around plumbing. In these areas, individual roaches nestle into cracks and crevices that are around 5 mm in length.

Unlike German cockroaches, brown-banded cockroaches are often found at high elevations within structures, such as ceiling voids and within the upper portions of wall voids, and they do not require as much moisture as most cockroach species. Brown-banded cockroaches are usually found nesting in the warmest areas of homes, and they are well known for nesting within hot interior spaces of electronic devices, such as TV’s and appliances. American cockroaches nest within hot and excessively moist conditions, particularly around tubs, below sinks, below washers and on the upper corners of basement walls. These large roaches are quick to invade pantries in order to feed on human foods, particularly sweets. Oriental cockroaches are similar to German cockroaches in terms of indoor nesting sites, and the fifth most medically significant cockroach species, the smokybrown cockroach, only inhabits the southeastern states.

Do you believe that your home has seen numerous cockroach infestations in the past?