American Cockroach

American cockroach
American cockroach


Key facts:

Latin name: Periplaneta americana

Life-cycle length: 600 days

Adult life span: 12+ months

Adult size: 40 mm

Wings: Yes. Will fly in warmer temperatures

Geographic distribution: Found across Australian although numbers are significantly higher in the tropics and along the east coast.

Preferred locations: In gardens, drains, sub-floor, roof void

The adult American cockroach is red/ brown, with a pale band around the pronotum (shield covering the head) and along the upper margin of the forewings. They are a large cockroach of up to 40 mm.

The young cockroaches (nymphs) are dark brown / black, with darker strips on the body segments. When the nymphs first hatch they are around 6 mm.

The are often confused with the Australian cockroach, which slightly smaller and has pale stripes on the upper forewings.

American cockroaches are one of the key cockroach pests in Australia. They are a peri-domestic cockroach, which means then tend to live outside around the perimeter of dwellings, but will readily come in side looking for food and shelter.

American cockroaches live in drains and around garbage, so they can readily transfer a range of diseases to humans when they walk over food and food preparation surfaces, in particular gastro diseases such as Salmonella and E.coli.

Not many people realise that cockroaches are a major cause of asthma in inner city apartment blocks. If American cockroaches establish a significant population indoors, their spend skins and droppings have the potential to cause of allergic reactions and asthma.

As with all cockroach species, the chances of suffering an American cockroach infestation can be reduced through good hygiene to remove any potential food sources:

  • Don’t leave dirty dishes out
  • Clean up any food spills
  • Regularly clean the cooker and under the dishwasher and fridge.
  • Put opened food into well sealed containers
  • Don’t leave uneaten pet food out

However, since American cockroaches are primarily an outdoor species, take actions to prevent cockroaches entering a building in the first place – install well-fitting insects screens and weather strips, and fill any cracks and crevices.

Ensure rubbish is put into bags, sealed and place in garbage bins will well-fitted lids, stored away from the building.

Fixing any leaks and areas of moisture inside the home will make internal areas less attractive.

As American cockroaches are primarily an outdoor cockroach, which is looking to come inside, a comprehensive spray to external areas with a residual insecticide spray, such as PestXpert Pro-Spray Outdoor Perimeter, will provide long lasting protection.

Areas to target:

  • Complete spray around the perimeter of the building, 1 m up the wall and 1 m out from the wall
  • Around windows, doors, vents, weepholes and other entry points
  • Around drains
  • In and around garbage bins

If you do have a problem inside, the use of a professional quality cockroach bait, such as PestXpert 2 in 1 Cockroach Bait, can be very effective in eliminating the population (especially in areas where you may not want to spray).