Cockroach species

There are over 3,000 different species of cockroaches - some are considered pests while others are beneficial in their natural environment.

The three main types of cockroaches commonly found in homes in New Zealand include the German cockroach, Gisborne cockroach and American cockroach.

See below for facts and information on types of cockroaches common in New Zealand:

German Cockroach

(Blatella germanica)

Appearance

• Notorious for their world-wide distribution, German cockroaches are easily identifiable by 2 dark longitudinal stripes on their pronotum. Adults grow to approximately 12 – 15mm in length.

Life cycle and habits of the German Cockroach

Lifecycle

• Females carry 35 – 40 eggs in an ootheca (egg case) until they are ready to hatch.
• Hatch in 1 month.
• Nymphs take between 6 weeks to 6 months to develop into adults.
• Generally 3-4 generations per year.

Habits

• Most commonly found indoors.
• Prefers wet, humid conditions and are typically found in kitchens and bathrooms in homes and commercial properties.

American Cockroach

(Periplaneta americana)

The American cockroach is one of the largest pest cockroaches to invade homes and commercial properties.

Appearance

• 35 - 40mm long.
• Shining red–brown in color.
• Wings longer than the body in male; only just overlap abdomen in female.
• Runs (may fly at very high temperatures).

Life cycle and habits of the American Cockroach

Lifecycle

• The ootheca (egg case) containing up to 16 eggs is carried by the female for several days before being deposited. Sometimes cemented down and tend to be grouped.
• Hatch in 1 – 2 months.
• Nymphs usually develop in 6 -12 months, but it can take up to 15 months.

Habits

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

Gisborne cockroach

(Drymaplaneta semivitta)

Appearance

• Up to 45mm long
• Dark brown to black with distinctive white bands.

 Lifecycle and habits of the Gisborne Cockroach

Lifecycle

Incomplete metamorphosis. Develops to adult through nymphal stages

Habits

• It is harmless, unlike German or American cockroaches, it does not spread disease, nor can it fly.
• It typically doesn't invade food supplies, unless they're decaying. It prefers to stay outside under bark or woodchips, however will come inside if it's wet or too hot.