Cockroaches: Facts, Identification & Control
How to identify Cockroaches?
The Australian cockroach is one of several species of peridomestic cockroaches. These are cockroaches that live mostly outdoors but may be found indoors. This species resembles the American cockroach but can be distinguished by the presence of light yellow bands on upper margins of the forewings.
Where do they live?
Australian cockroaches are typically found outdoors. They can be found under the bark of trees and in locations with moisture. When indoors, the Australian cockroach can be found near water pipes, sinks, toilets, cupboards and other environments with dark and warm conditions.
How do they live?
These roach like their other counterparts have 3 life stages: egg, nymph, and adult. The eggs are deposited into an ootheca (an egg case). The egg case may be as long as 11mm. The ootheca is attached to and carried by the adult female on the tip of her abdomen and deposited long before the eggs hatch. An ootheca may contain as many as 24 eggs. From egg to nymph takes about 40 days. The ootheca is often dropped or glued in hidden cracks and crevices. An adult female can lay about 20-30 oothecae in her lifetime.
Nymphs are wingless. Light-yellow spots on top of the abdomen can be found on the nymphs of the Australian cockroach. The nymphs become mottled (spotted or blotchy) gradually as they continue to develop. The nymphal stage takes 6-12 months.
The adults are about 32-35mm long and range in color from reddish-brown to dark-brown and have completely developed and functional wings, capable of gliding flight. It takes about 24 days for a newly molted female to produce the first ootheca. Development from egg to adult requires about one year, with adult females surviving for an additional 4 to 6 months.
How do they affect us?
Cockroaches are closely associated with humans and commonly dwell in places of poor sanitation. These pests may affect human health. They contaminate food with their excrement and also spread pathogens.
These cockroaches also induce allergies caused by inhalation, ingestion, dermal abrasion or injection of cockroach-produced allergens. Symptoms of allergies caused by cockroaches can be sneezing, skin reactions and eye irritation.
How to control them?
The keys to controlling cockroaches are sanitation and exclusion: cockroaches are likely to reinvade as long as a habitat is suitable to them (i.e., food, water, and shelter are available).