The German cockroach (Blattella germanica) is a small species of cockroach, usually about 1.3 cm to 1.6 cm long, tan to light brown in color. The adults are winged, but do not fly. Originally from Africa, it is now the most common and most economically important household pest in the United States. They are common throughout the world, and although they are not cold tolerant they have been found even in the most northerly locations in close association with humans. German cockroaches carry organisms that cause disease, principally bacteria, protozoans, and viruses that cause gut symptoms (food poisoning, dysentery, and diarrhea). They also produce malodorous secretions that taint the flavor of food, and their cast skins are allergens, but they are mostly aethetic pests. Their flat bodies allow them to live in cracks and crevices of human habitations, often in large numbers. German cockroaches scavenge on any food, and even non-food stuffs, such as soap and glue, that are left around, and are commonly found in garbage receptacles. Mostly nocturnal, these insects are very hardy and resilient, and are difficult to exterminate. Females protect their young by holding their eggs in an ootheca until they hatch. Sanitation, keeping garbage containers sealed, putting food away and caulking holes in walls to limit access are helpful for controlling German cockroaches. Chemical baits and dusts also can help.
(Antani and Burgeson 2011; Jacobs 2007; Valles 2008; Wikipedia 2011)