Soil Science

Cockroaches

Not all cockroaches are "nasties" that inspire loathsome feelings on opening the kitchen cupboard on a summer night. The wingless cockroach pictured below does not invade houses to eat what's dropped on the floor behind the stove. It was found in a rotting log where it sheltered and slowly chewed through the wood. They are fast movers once disturbed and you have to be quick to scoop them up in your hand. They are oval, hard-bodied insects with 3 pairs of legs and short antennae on the head. Some are even more flattened which allows them to move through rotting wood easily.

Two types of native Australian wingless cockroach.
Two types of native Australian wingless cockroach.

Australia has many species of native cockroaches, most of which are brown or black and wingless and live outside in gardens and the bush. The ones that are pests in houses are all introduced. What is special about Australian cockroaches is that we have the only cockroaches that burrow in soil. They emerge from their burrows at night to collect dead leaves to eat in their burrow.

Most Australian cockroaches eat dead vegetation (leaves, wood or other organic detritus). They can be quite large.

Large cockroach found in rotten rainforest log.
Large cockroach found in rotten rainforest log.

Strange but true: Australia hosts the biggest cockroach in the world! This is the enormous (for a cockroach) rhinoceros cockroach of North Queensland. It can weigh up to 30 grams and be 8 cm long. It can burrow up to 1 metre deep and is quite a friendly chap, sharing its burrow with other soil-dwellers such as silverfish, other cockroaches, beetles and even frogs.

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