The size of an adult is 12-15 mm in length. They are mid-brown in colour. The females wings are only 2/3 in length where as the males are full size. They have very long antennae and long spiny legs.
The German Cockroach follows the state of incomplete metamorphous Egg – nymph – adult.
The mated female cockroach produces a complicated egg containing structure called an ootheca, containing a variable number of eggs, up to a maximum of 30. She carries the ootheca attached to her abdomen up until the young nymphal cockroaches are about to hatch and burst out of the seam of the ootheca. This period is dependable upon the temperature it can take 2-4 weeks.
The freshly hatched nymphs are white, but rapidly darken to a medium brown and undergo a variable number of skin molts, averaging about 6/7. At each molt the insect grows slightly larger and gradually comes to resemble the adult insect by increasing the antennae length and developing large wing buds. Minor or even major injuries early in the nymphs’ development can be repaired and regenerated during subsequent skin molts.
The adult cockroaches emerge from the final nymphal stage between 2.5 and 6 months later, and are sexually mature.
They are omnivorous and will scavenge on any form of organic material, including human waste products. They need a free-water source and inevitably hide in the vicinity of taps, sinks and drains.
Why are cockroaches pests?
The German Cockroach is known to carry and spread various human disease organisms. Its habit of walking on and feeding on putrefying waste materials, drinking at unsavory water supplies. They then freely walk over food preparation areas, cutlery and crockery and human foods in its search for further food enables it to spread many disease organisms.
The rapid scurrying and running action of cockroaches is very upsetting to humans.