German Cockroach (Blattella germanica)
Adult German Cockroaches are about 17mm in length and light brown except for the shield behind the head marked with two dark stripes, which run lengthwise on the body. The nymphs are wingless and nearly black with a single light stripe running down the middle of the back. Egg capsules are light ta
Egg cases are carried by the female until just before hatching and each female may produce four to six cases during her lifetime, each containing 30 to 40 eggs. Eggs hatch in 28 to 30 days, and nymphs develop in 40 to 125 days.
Female Cockroaches live about 200 days (slightly longer than the male). The German Cockroach produces more eggs and has more generations per year (three to four) than any other cockroach, and only a few individuals are needed to develop into an infestation. The German cockroach is omnivorous and a scavenger.
They particularly like starch, sugary foods, grease and meats. In certain situations where there is a shortage of foodstuffs, they may eat household items such as soap, glue and toothpaste or they may even turn cannibalistic, often chewing on the wings and legs of each other. Diseases known to be carried by the cockroach include various different strains of Salmonella, Tapeworm, Gastroenteritis, Amoebic Dysentery and Tuberculosis. During any infestation, housekeeping and hygiene measures must be upgraded.
Oriental Cockroach (Blatta orientallis)
Usually dark reddish brown in colour, adults are about 25mm in length and the immature cockroaches (nymphs) resemble adults except that they are wingless.
Unlike other cockroaches, Oriental’s cannot climb up smooth surfaces. They generally live in moist areas, but can survive in dry areas if they have access to water. They prefer cooler temperatures and thus are common in basements, boiler rooms and walkways adjacent to buildings. The Oriental Cockroach breeds well in unventilated crawl spaces or basements where humidity is high. Adult cockroaches can live up to one year, during which females produce an average of 150 young.
The Oriental Cockroach in contrast with the German Cockroach, indiscriminately lay their eggs in dark out of the way locations just hours after development. This combined with the knowledge that they could literally be anywhere within a building and could hatch at any time, up to two months after being laid, makes effective treatment a job for the professional.
An integrated approach involving the use of cockroach traps, insecticidal gels and well-targeted use of residual insecticides where appropriate is recommended.