Cockroaches are of ancient origin tracing back over 400 million years. They have not changed much and are distributed all over the world. Belonging to the order of Dictyoptera which contains over 4,000 species, the “domestic” or “domiciliary” species that adapted to human habitats are the troublesome ones for men.

In Singapore, the five common domestic species are:

1) American Cockroaches (Periplaneta Americana)
2) Australian Cockroaches (Periplaneta Australasiae)
3) Brown Cockroaches (Periplaneta Brunnea)
4) German Cockroaches (Blatella Germanica)
5) Oriental Cockroaches (Blalla Orientalis)

Their life cycle pass through 3 stages from egg, nymph to adult (incomplete metamorphosis) with their eggs deposited in groups and protected by a protective cover called the ootheca or egg case. Depending on the species of cockroaches, the number of eggs in each ootheca can range from 16 up to 40. Of the species, the German cockroaches are the most resilient & there are numerous findings of chemical resistance making control of them difficult. At the same time, the female German cockroaches carry their eggs with them and only deposit them when they are about to hatch, thus starting an infestation again.

Vectors of numerous diseases such as cholera, dysentery, typhoid fever and salmonellosis, etc that caused food poisoning to humans, they are also highly resistant to harsh environment and can live almost a month with food and 2 weeks without water.