Common Cockroach Species

Over 3,000 different species of cockroaches exist with some considered as pests while others prove beneficial in their environment. In South Australia, there are three main types found in homes including the American, Oriental and German cockroach.

American Cockroach

(Periplaneta americana)

One of the largest pest cockroaches to invade Australian homes, is the American cockroach.

American cockroach

Appearance

  • 35 - 40mm in length.
  • Red-brown shiny colouring.
  • Wings overlap abdomen in the female and are longer than the body in the male.
  • Run but may fly at very high temperatures.

Lifecycle

  • The egg case (ootheca) contains up to 16 eggs is carried by the female American cockroach for several days.
  • The eggs are sometimes cemented down and tend to be dispersed in groups.
  • Eggs take 1 – 2 months to hatch.
  • Nymphs develop into adults between 6 -12 months, but can take up to 15 months.

Habits

  • The American cockroach is also known as the ‘Palmetto bug’ because they live on trees. They prefer humid, dark and undisturbed areas and can be found in kitchens, subfloors, bathrooms and roof voids of homes.

Australian Cockroach

(Periplaneta australasiae)

Lifecycle

  • Female Australian cockroaches deposit the egg case (ootheca) containing 24 eggs a day after production.
  • Nymphs take 6-12 months to develop into adult cockroaches.

Habits

  • They commonly enter homes at night from gardens or debris.
  • Where winters are relatively mind, they are generally more prevalent in these areas.
  • Despite its Australian name, this cockroach is not a native species.

Brown Banded Cockroach

(Supella longipalpa)

Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org

Appearance

  • The Brown Banded cockroach is one of the smallest pest cockroaches. They are approximately 10 – 15mm in length and can be identified by the yellow-brown stripes across their abdomen.

Lifecycle

  • Female produces up to 13 oothecae (egg case), each oothecae contain 16 eggs.
  • Nymphs take 55 days to develop into adults.
  • In ideal temperature conditions (30°c), adult lives 90 – 115 days.

Habits

  • They mainly stay on the ground, but in very warm climates they may fly. They prefer humid, warm environments such as heated buildings. They are commonly found in inside and around appliance motors and in ceilings. Brown Banded cockroaches are primarily active at night, feeding opportunistically on materials with high starch contents.

German Cockroach

(Blatella germanica)
German Cockroach

Appearance

  • German cockroaches are known for their worldwide distribution and are easily identified by 2 dark stripes on their pronotum (this covers the surface of their thorax). Adult German cockroaches grow to a length of approximately 12 – 15mm.

Lifecycle

  • Female German cockroaches carry 35 – 40 eggs in an egg case (ootheca) until the eggs are ready to hatch in 1 month.
  • Nymphs develop into adults between 6 weeks to 6 months.
  • Approximately 3-4 generations of German cockroaches per year.

Habits

  • German cockroaches prefer humid conditions with areas of constant heat and moisture. They are commonly found in kitchens of homes, laundry's and bathrooms (mainly found indoors).

Smoky Brown Cockroach

(Periplaneta fuliginosa)

Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org

Appearance

  • 3-35 mm in length.
  • Dark brown shiny colour.
  • Wings overlap abdomen in female and are longer than the body in male.
  • Run and may fly in very high temperatures.

Lifecycle

  • Smoky Brown females deposit the egg case (ootheca) containing 22-26 eggs a day after production.
  • Nymphs develop into adults between 6-12 months.
  • The lack of wings in the young is the noticeable difference between nymphs and adults (apart from size).

Habits

  • Smoky Brown cockroaches lives under bark, in hollow trees, under floors, and enter homes of a night.
  • They are nocturnal and generally hide during the day in cracks and crevices, especially where it is warm.
  • Commonly known for entering houses and contaminating food with regurgitated salivary fluid, excrement, and potentially harmful bacteria.