Cockroaches

Insecta Blattodea

  • Nocturnal Cockroaches hide during the day in for example, cracks in walls, under electrical appliances, below sinks, around water heaters, in drains and grease traps, roof voids and gardens.
  • Commonly found in kitchens where food scraps are present.

Most Active

CockroachPeakSeason

All species are active year round but the peak activity period is in the warm summer months.

Life cycle

  • Eggs are laid in an egg case (either deposited or carried by the female)
  • Nymphs resemble the adults, but are lighter in colour and smaller
  • Nymphs go through several moults before they reach the adult stage

Damage/symptoms

Contaminate food, transmit disease (e.g. salmonella, diphtheria, staphylococcus, streptococcus), can cause allergies such as asthma and dermatitis. Evidence of infestation includes tiny faecal droppings, smudges from regurgitated food, egg cases and shed skins.

Control

  • Use a surface barrier spray with kill and control properties. Barrier sprays discourage cockroaches from entering the home. NOTE: the effectiveness of chemical control may be limited by poor hygiene.
  • When applying barrier sprays, it is important to note that cockroaches tend to aggregate in corners and confined spaces, and generally travel along the edges of walls or other surfaces.

Prevention checklist

  • Reduce available food: keep food in sealed containers; dispose of garbage regularly; ensure the house (particularly kitchen) is clean, including under appliances; do not leave pet food out overnight.
  • Reduce available water: repair leaky taps and pipes; remove unnecessary containers of water.
  • Reduce areas which could provide shelter for cockroaches: do not stack newspapers in the house, keep compost bins screened and away from the house.
  • Reduce entry points to a building: repair holes, cracks and gaps in walls and skirting boards.
Identification Description Nesting habits Feeding habits

German cockroach, Blattella germanica
image 12-15 mm Light amber brown Nymphal development: 6-12 weeks Widespread – most common species Warm, moist locations Typically infests indoors

American cockroach, Periplaneta americana
image 35-40 mm Reddish brown Nymphal development: 6-12 months Northern coastal areas Common in sewer systems and food preparation/eating facilities Typically infests outdoors

Smokybrown cockroach, Periplaneta fuliginosa
image 30-35 mm Dark brown to almost black Nymphal development: 6-12 months Coastal areas of NSW Typically infests outdoors

Australian cockroach, Periplaneta australasiae
image 30-35 mm Brown with yellow markings Nymphal development: 6-12 months Tropical and subtropical areas of QLD & NSW Typically infests outdoors

Brownbanded cockroach, Supella longipalpa
image 10-14 mm Pale brown with pale banding Nymphal development: 2-4 months Warmer Northern areas of WA, NT & QLD Typically infests indoors

Oriental cockroach. Blatta orientalis
image 20-25 mm Dark brown to black Nymphal development: 6-18 months Cool southern areas Infests outdoors & indoors