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Sticker of Australasian giant water bug
Bug card No. 0205 of 4,939

Australasian giant water bug

Lethocerus insulanus
Eats: Other bugs and small animalsTrue bugs and cicadasPonds, rivers and shores6 legs

The Australasian giant water bug is the biggest true bug in Australia. It hides very still in the water and waits for prey to swim past. Then it grabs it fast.

Lives in
Northern and eastern Australia, Papua New Guinea and New Caledonia, in lakes, ponds and floodwaters
Length
5 to 7 cm (2 to 2.8 in)
Top speed
about 4.3 km/h (2.7 mph)
Swimming, estimate
Can it hurt you?
Can bite

Watch out! Read about its close cousin on Venom Wiki →

What does it eat?
It ambushes fish, frogs, small reptiles and other water animals.
For real!Photo of Australasian giant water bug
Picture by Canley. CC BY-SA 3.0, via Wikimedia Commons.

How big is it?

How long is it?

Australasian giant water bug about 7 cm long (2.8 in)A toy building brick about 3.2 cm (1.3 in)A crayon about 9 cm (3.5 in)A banana about 18 cm (7.1 in)
as long as 2 toy building bricks in a rowcould swim the length of a bathtub in 1.7 seconds

How big is Australasian giant water bug compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

How fast is it?

cool stuff

Fun facts

1

It breathes under water through a little tube at the end of its body, like a snorkel.

2

It has wings and flies off to find a mate or a new pond.

you asked

Most asked questions about Australasian giant water bug

?How big is the Australasian giant water bug?

About 5 to 7 centimetres long, the biggest true bug in Australia.

?What does the giant water bug eat?

Fish, frogs, small reptiles and other water animals that it catches by surprise.

For bug experts

Scientific name
Lethocerus insulanus
Group
True bugs and cicadas
Family
Belostomatidae
Classification
Insecta > Hemiptera > Belostomatidae
Lives on
Australia and Oceania
Also known as
Australian giant water bug, Electric light bug, Giant fishkiller, Toe biter

Where the facts come from

  1. Lethocerus insulanus (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
  2. Picture by Canley. CC BY-SA 3.0, Wikimedia Commons. The sticker of this bug is drawn from this picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at [email protected] and we will fix it.

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Also at home here: Ponds, rivers and shores

Beautiful demoiselleDragonflies and damselfliesGreat pond snailSnails, slugs and wormsBroad-bodied chaserDragonflies and damselfliesGolden-ringed dragonflyDragonflies and damselfliesStriped fishing spiderSpidersHorse leechSnails, slugs and worms
Honey jarfor grown-ups