Australian_Geographic_2015_07-08.

20 Australian Geographic

Cockroaches are considered

pests and often squashed under

foot without a care, yet some native

varieties are surprisingly attractive.

AUSTR ALIAN COCKROACHES

N

EXT TIME YOU reach for insecticide to

smite a cockroach out of existence, think

twice. Although some are introduced pests,

others have been here for millions of years, and are

deserving members of Australia’s intricate ecosys-

tem. There are more than 530 known species in

Australia, about 90 per cent of which are found

nowhere else – and experts believe there may be

twice that number yet to be discovered.

Cockroaches are closely related to termites and

have a characteristic flattened body. Their lives are

short but varied and often unique. Some have

elaborate mating rituals and others use chemical

sprays to defend themselves. Some species take

parental care of their young. They range in size

from the tiny Nocticola, at just 3mm long, to the

giant burrowing cockroach at a whopping 8cm and

33g – one of the world’s heaviest insects. They can

also be far more colourful than the non-native

invaders you might see darting about at night.

The dazzling greens, reds and even blues of some

species hint at the incredible diversity to be found.

Cockroaches occupy every type of terrestrial

habitat Australia has to offer, from rainforest

canopies to caves and beneath the red dirt of the

outback. There’s even an Australian aquatic

cockroach that’s yet to be properly studied.

One man who’s spent his life exploring the

secrets of these fascinating insects is entomologist

David Rentz, author of A Guide To The Cockroaches Of

Australia. “They are extremely abundant and crucial

in the breakdown of leaf matter in the Australian

environment,” says David. “They are also a major

food source for vertebrates, such as lizards, frogs

and birds, and invertebrates, such as centipedes,

scorpions and predatory beetles.” Most have

interesting life histories that we know little about.

Although it’s unlikely you’ll see the species

pictured here in your kitchen cupboards, they are

some of the more extraordinary Australian

members of this much-maligned insect family.

Beautiful

bugs

TEXT BY DAN DOWN ILLUSTRATIONS BY MICHAEL BURLEIGH

MITCHELL’S DIURNAL

COCKROACH

Polyzosteria mitchelli

Surely the most dazzling of all

Australian roaches, Mitchell’s diurnal

cockroach sports a yellow-patterned,

green-blue carapace, with striking

blue legs. It has a wide range

stretching from WA, through SA and

into NSW, and can be seen scurrying

about around shrubs during the day.

Head to the Nullarbor Plain for a

chance to spot this colourful insect.

CONFUSING SUN COCKROACH

Pseudolampra rothei

This medium-sized cockroach has

vibrant dark-red-and-yellow-striped

armour, mottled with black marks. Its

head is a rich red-brown with three

lighter stripes at the top. This

stunning species can be found in SA’s

vast Lake Eyre Basin, but hasn’t been

seen outside of the state. The

‘confusing’ part in the name refers to

the fact that it looks very similar to

other ’roaches in its genus – a

problem entomologists love to tackle.

COMMON ELLIPSIDION

Ellipsidion humerale

This colourful species varies in appearance and is

widespread, having been identified in WA, the

NT, QLD and as far afield as New Guinea. You’ll

know it when you see it because it has a striking

orange-yellow back and its antennae are often a

two-tone black-orange. The species is active

during the day and doesn’t live in leaf litter –

look for it on flowers and leaves, where you

may find it supping on pollen.

圀漀爀氀搀䴀愀最猀⸀渀攀琀圀漀爀氀搀䴀愀最猀⸀渀攀琀

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