Bush cockroach fact sheet | Field of Mars EEC

What are bush cockroaches?

Bush cockroaches are native cockroaches that live in natural habitats such as leaf litter, mulch, bark, logs and soil. They are different from the introduced cockroaches that can become pests in houses and buildings.

Australia has hundreds of native cockroach species. Many are brown or black, but some have bright colours and patterns. Most bush cockroaches are harmless to people and spend much of their time hidden in bushland.

Cockroaches belong to the insect order Blattodea. Like other insects, they have six legs, antennae and a hard exoskeleton. Their flat bodies help many species squeeze under bark, stones and fallen logs.

A bush cockroach.

Mitchell’s diurnal cockroach is one of Australia’s most colourful native cockroaches.

Where do bush cockroaches live?

Bush cockroaches live in many different land habitats. In bushland, they are often found in leaf litter, under bark, beneath logs, under stones or in loose soil. Some species live in trees, caves, animal burrows or their own burrows.

At Field of Mars Reserve, bush cockroaches are most likely to be found in moist leaf litter, rotting wood and sheltered places where they can hide from predators and drying sunlight. Fallen leaves, bark and logs are important habitat for many small bushland invertebrates.

Bush cockroaches often shelter on bark, branches, logs and leaf litter.

What do bush cockroaches eat?

Many bush cockroaches feed on dead leaves, bark, rotting wood, fungi and other decaying plant material. Some species that live in trees may feed on pollen, bark or leaves.

By feeding on dead plant material, bush cockroaches help break it into smaller pieces. Their droppings return nutrients to the soil, where they can be used again by plants, fungi and other decomposers.

Bush cockroaches help break down dead leaves, bark and other plant material.

What is the life cycle of a bush cockroach?

Bush cockroaches grow through incomplete metamorphosis. This means they do not have a caterpillar or pupal stage. Instead, young cockroaches hatch as nymphs that look like smaller versions of adults.

Many cockroaches lay eggs inside a protective case called an ootheca. In some species, the female carries or protects the egg case. Other species keep the eggs inside the body until the young hatch.

Nymphs grow by moulting. Each time a nymph moults, it sheds its old exoskeleton and forms a larger one. After several moults, the nymph becomes an adult. The time taken to grow depends on the species and its habitat.

Some cockroaches carry an ootheca, or egg case, before the young hatch.

Juvenile bush cockroaches, known as nymphs, often resemble adults, with some variation in colour or texture. Some also lack wings.

What adaptations do bush cockroaches have to help them survive?

Bush cockroaches have several adaptations that help them survive in leaf litter and bushland habitats. Their flattened bodies help them squeeze into narrow spaces under bark, rocks and logs. Their long antennae help them feel their way through dark spaces and detect food, shelter and other animals.

Many species have spiny legs that help them grip rough surfaces and move quickly through leaf litter. Brown, black or patterned colours can help them blend in with soil, bark and dead leaves. Some species are mostly active at night, which helps them avoid predators and drying heat.

Some bush cockroaches use extra defences. A few can release strong-smelling chemicals, roll into a ball, hiss or dig burrows to escape danger.

A Botany Bay cockroach in Dharawal Nature Reserve, New South Wales. Native cockroaches use camouflage, long antennae and spiny legs to move through bark, logs and leaf litter.

Why are bush cockroaches important?

Bush cockroaches are important decomposers. They help recycle dead leaves, bark, wood and fungi in bushland habitats. Without decomposers, dead plant material would build up and nutrients would be locked away instead of returning to the soil.

Bush cockroaches are also part of the food web. They are eaten by spiders, centipedes, lizards, birds, frogs and small mammals. Even though they are often hidden, they help keep bushland ecosystems working.

Some native cockroaches feed on fungi and other organic material as it breaks down.

How can you help bush cockroaches?

You can help bush cockroaches by protecting the small habitats they need. Leave leaf litter, bark and fallen logs in place where it is safe to do so. These natural materials provide shelter, food and moisture for many invertebrates.

If you look under a log or stone during a fieldwork activity, gently return it to the same position. Avoid spraying pesticides outdoors unless they are really needed. Bush cockroaches and other decomposers are important parts of healthy soil and bushland habitats.

Leaf litter, bark and fallen logs provide food and shelter for many decomposers, including bush cockroaches.

Related fact sheets

More invertebrate fact sheets

• Invertebrate fact sheets – overview
• Insects fact sheet – explains insect features and how cockroaches fit into the insect group.
• Myriapod fact sheet – many-segmented invertebrates like centipedes and millipedes.
• Gastropod fact sheet – slugs and snails that also live in moist soil and leaf litter.

Habitats and ecosystems

• Leaf litter habitat fact sheet
• Field of Mars Reserve fact sheet

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