German Cockroach (Blattella germanica)

Identification

• Is the most common and economically important of the cockroaches in Canada
• Adults are approximately 13 to 16 mm in length
• Colour is light brown to tan; it can be promptly identified by the two dark longitudinal lines on the pronotum (shield behind head)
• Males exhibit a much more tapered abdomen than females

Habitat and Behaviour

• Prefers warm, moist environments with adequate food sources
• Is generally introduced into structures with shipment or packages
• Does not readily move between buildings
• Has specialized tarsal (“foot”) pads that allow it to walk on windows, walls, and ceilings
• Typically spends up to 75% of its time in a harbourage area, often a small space (1 to 5 mm) where it feels protected
• Is not social, although it does aggregate; it individually searches for food and will feed on almost anything available
• Is nocturnal—mainly active at night—but can be seen in the day in a heavy infestation
• Is linked to the spread of illness via pathogenic microbes
• Droppings and cast skins contain a large number of allergens

Lifecycle

• Undergoes gradual metamorphosis (egg, nymph, adult)
• Nymphs are smaller versions of the adults and will go through several molts until fully grown
• Has very high reproductive potential
• Female produces egg capsule (ootheca) containing an average of  35 eggs
• Ootheca is carried around by the female until a few hours to hatching
• Female produces an average of 5 oothecae during her lifetime, with an ootheca produced at an interval of 20 to 25 days
• Lifecycle, from egg to adult, can range anywhere from 50 to 200 days
• Population will typically be comprised of 75% nymphs