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Sticker of Radon Saint Andrew's cross spider
Bug card No. 3472 of 4,939

Radon Saint Andrew's cross spider

Argiope radon
Eats: Other bugs and small animalsSpidersPonds, rivers and shores8 legsNot an insect, but a bug cousin

This orb web spider lives in the warm north of Australia. The female has a white, hairy body framed in black. She decorates her round web with a thick zigzag band of silk that runs from corner to corner.

Fun fact: spiders are not insects. Insects have six legs, spiders have eight. Everyone calls them bugs anyway!
Lives in
Northern Australia, along rivers and streams in tropical grassland
Length
1.8 to 2.8 cm (0.71 to 1.1 in)
the female; the male is only 5 to 9 mm
Top speed
about 2 km/h (1.2 mph)
On foot, estimate
Can it hurt you?
Harmless

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

What does it eat?
It catches flying insects in its web.
For real!Photo of Radon Saint Andrew's cross spider
Picture by Summerdrought. CC BY-SA 4.0, via Wikimedia Commons.

How big is it?

How long is it?

Radon Saint Andrew's cross spider about 2.8 cm long (1.1 in)A grain of rice about 6 mm (0.24 in)A toy building brick about 3.2 cm (1.3 in)A crayon about 9 cm (3.5 in)
as long as 5 grains of rice in a rowcould run across a dinner table in 1.8 seconds

How big is Radon Saint Andrew's cross spider compared to YOU?

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How fast is it?

cool stuff

Fun facts

1

The male is tiny next to the female. She can be three times as long as he is.

2

Its belly reflects ultraviolet light, a colour we cannot see but bees can. This helps lure insects closer.

3

A spider with a full tummy builds longer web decorations than a hungry one.

4

Many of them build their webs close together over the water, but some live alone.

5

It fixes holes in its web very fast, so its web lasts longer than the webs of most spiders.

you asked

Most asked questions about Radon Saint Andrew's cross spider

?Why does it put a zigzag in its web?

The bright silk decorations attract insects, so webs with decorations catch more food.

?How big is it?

The female's body is about 2 to 3 centimetres long. The male is much smaller.

For bug experts

Scientific name
Argiope radon
Group
Spiders
Family
Araneidae
Classification
Arachnida > Araneae > Araneidae
Lives on
Australia and Oceania
Also known as
Northern St Andrew's cross spider

Where the facts come from

  1. Argiope radon (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 Summerdrought. CC BY-SA 4.0, 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

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Honey jarfor grown-ups