Australian cockroach (Periplaneta australasiae)

Australian cockroach


Despite being called the Australian cockroach, it is not native to Australia and is suspected to have originated in Africa.

Found worldwide, common in many tropical and sub-tropical areas.

Prefers warm to hot, moist habitats. Typically they are an outdoor cockroach, living in the leaf litter, under bark and in wood piles, but will establish themselves indoors in dark, warm, moist areas – pipework, sinks and bathrooms. They are considered peridomestic cockroaches in that they live in and around buildings.

Australian cockroaches live in aggregations – cockroaches of all ages (young nymphs to adults). Whereas the cockroaches don’t activity co-operate as a community, the young cockroach nymphs, which tend not to leave the harbourage, benefit from this arrangement as they feed on the droppings and vomit of older cockroaches.


Colour: Reddish / dark brown, with a pale band around the pronotum (shield covering the head) and along the upper margin of the forewings.

Size: Up to 35 mm

Males and females look very similar from the dorsal side (no difference in wing length). From underneath, the cerci are visible in the female.


Colour: Dark brown / black, with obvious yellow spots on the abdominal segments which can become more blotchy in the older nymphs.

Size: From 5-30 mm

Eggs: 24 eggs per ootheca (egg case). Ootheca deposited in hidden cracks and crevices a couple of days before egg hatch.

Number of nymphal stages/moults to adult: 5

Length of life-cycle (Egg to adult): 365 days

Life span of adult: 6 months+

Cockroaches will eat everything! They are scavengers that will eat any organic matter. Australian cockroaches are particularly known for also causing damage to plants, especially seedlings.

  • Both male and female adults are capable of short, gliding flight
  • Sometimes confused with the American cockroach, which is bigger and lacks the pale stripe on the upper margin of the forewing

Although cockroaches are generally are known to carry a wide range of diseases and their spent skins and dropping contain allergens that can cause allergic reactions and asthma, this hasn’t been demonstrated in the real world with Australian cockroaches. However, laboratory experiments have shown that Salmonella can be transferred by Australian cockroaches.

Good hygiene is key to preventing a cockroach infestation:

  • Keep food preparation areas clean – clean up food spills and clear away dishes after meals
  • Make sure the dishwasher is run regularly
  • Regularly clean cooker, grill, extraction fan, dishwasher and refrigerator (especially underneath)
  • Don’t leave unfinished pet food out overnight
  • Fix any leaks and areas of moisture
  • Fill any cracks and crevices, that would allow cockroaches easy access from the outside – this is particularly important for Australian cockroaches as they are primarily an outdoor cockroach
  • Ensure rubbish is put into sealed containers

More information on cockroaches.

Treatment notes:

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