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.
Fast facts – Bush cockroaches
Scientific group – Bush cockroaches are insects in the order Blattodea.
Appearance – Most have long antennae, chewing mouthparts, spiny legs, a flattened body and a hard exoskeleton.
Size – Different species range from a few millimetres long to about 80 millimetres in large burrowing cockroaches.
Diet – Many bush cockroaches eat dead leaves, bark, rotting wood, fungi and other decaying plant material.
Habitat – Bush cockroaches live in leaf litter, fallen logs, bark, soil, burrows and other sheltered land habitats.
Life cycle – Young cockroaches are called nymphs and grow into adults through incomplete metamorphosis.
Adaptations – Their flattened bodies, long antennae, spiny legs and camouflage help them move, hide and survive in leaf litter and under bark.
Ecosystem role – Bush cockroaches help recycle dead plant material and are food for spiders, lizards, birds, frogs and other animals.
Where do bush cockroaches live?
Bush cockroaches live in many different terrestrial 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 direct sun and drying heat. Fallen leaves, bark and logs are important habitats for many small bushland invertebrates.
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.
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.
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.
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.
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.
Related fact sheets
More invertebrate fact sheets
- Invertebrate fact sheets – explore more animals without backbones that live in bushland, soil, leaf litter and water.
- Insects fact sheet – explains insect features and how bush cockroaches fit into the insect group.
- Termite fact sheet – learn about insects closely related to cockroaches that also recycle dead plant material.
- Springtail fact sheet – learn about tiny six-legged decomposers that live in damp soil, leaf litter and rotting wood.
- Common rough slater fact sheet – compare bush cockroaches with another leaf-litter animal that shelters in damp places.
- Millipede fact sheet – learn about many-legged decomposers that help break down dead plant matter.
- Centipede fact sheet – learn about a leaf-litter predator that shares habitat with bush cockroaches.
Habitats and ecosystems
- Leaf litter habitats fact sheet – explains the damp, sheltered habitat where many bush cockroaches live and feed.
- Rock and log habitats fact sheet – explores the cool, hidden shelters used by bush cockroaches and other small animals.
- Eucalypt forest fact sheet – explains the bushland ecosystem that provides leaf litter, bark and fallen logs.
- Field of Mars Reserve fact sheet – learn about the local reserve habitats that support native plants, animals and decomposers.
Attributions
References
Australian Museum. Native Cockroaches. [online] Available at: https://australian.museum/learn/animals/insects/native-cockroaches/
Australian Museum. Cockroaches: Order Blattodea. [online] Available at: https://australian.museum/learn/animals/insects/cockroaches-order-blattodea/
CSIRO. Blattodea – cockroaches. [online] Available at: https://www.ento.csiro.au/education/insects/blattodea.html
Gordon, L. and Salleh, A. Cockroaches can be smart and beautiful — and might even save the planet. ABC Science. [online] Available at: https://www.abc.net.au/news/science/2021-04-18/cockroaches-insects-reasons-love-them-environment/100053056
Australian Geographic. Our native cockroaches are beautiful. [online] Available at: https://www.australiangeographic.com.au/nature-wildlife/2018/04/our-native-cockroaches-arent-as-gross-as-you-think/
Bush Heritage Australia. Giant Burrowing Cockroaches. [online] Available at: https://www.bushheritage.org.au/species/giant-cockroaches
Field of Mars EEC. Insects fact sheet. [online] Available at: https://fieldofmar-e.schools.nsw.gov.au/fact-sheets/invertebrates/insects-fact-sheet
Field of Mars EEC. Leaf litter habitats fact sheet. [online] Available at: https://fieldofmar-e.schools.nsw.gov.au/fact-sheets/habitats/leaf-litter-habitats-fact-sheet
Field of Mars EEC. Rock and log habitats fact sheet. [online] Available at: https://fieldofmar-e.schools.nsw.gov.au/fact-sheets/habitats/rock-and-log-habitats-fact-sheet
Field of Mars EEC. Field of Mars Reserve fact sheet. [online] Available at: https://fieldofmar-e.schools.nsw.gov.au/fact-sheets/environments/field-of-mars-reserve-fact-sheet
Image attributions
A bush cockroach – Field of Mars EEC (original illustration).
Mitchell’s diurnal cockroach is one of Australia’s most colourful native cockroaches – “Mitchell’s Diurnal Cockroach” by Jean and Fred Hort. Creative Commons Attribution 2.0 Generic. Available at: https://www.flickr.com/photos/63479603@N00/15672294482
Bush cockroaches often shelter on bark, branches, logs and leaf litter – “Bronze beauty” by Jean and Fred Hort. Creative Commons Attribution 2.0 Generic. Available at: https://www.flickr.com/photos/jean_hort/5415930239/
Bush cockroaches help break down dead leaves, bark and other plant material – “Desert Racing Cockroach” by Jean and Fred Hort. Creative Commons Attribution 2.0 Generic. Available at: https://www.flickr.com/photos/jean_hort/24192890166/
Some cockroaches carry an ootheca, or egg case, before the young hatch – “Another cockroach” by Jean and Fred Hort. Creative Commons Attribution 2.0 Generic. Available at: https://www.flickr.com/photos/jean_hort/2852349136/
A Botany Bay cockroach in Dharawal Nature Reserve, New South Wales – “File:Polyzosteria limbata 2.jpg” by John Tann. Creative Commons Attribution 2.0 Generic. Available at: https://commons.wikimedia.org/wiki/File:Polyzosteria_limbata_2.jpg
Some native cockroaches feed on fungi and other organic material as it breaks down – “File:Wingless Cockroach feeding on some kind of mildew (5202469160).jpg” by gbohne. Creative Commons Attribution-ShareAlike 2.0 Generic. Available at: https://commons.wikimedia.org/wiki/File:Wingless_Cockroach_feeding_on_some_kind_of_mildew_(5202469160).jpg
Leaf litter, bark and fallen logs provide food and shelter for many decomposers – Field of Mars EEC (original image).
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