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Sticker of Common marine caddisfly
Bug card No. 1096 of 4,939

Common marine caddisfly

Philanisus plebeius
Name means: “plebeius means common”
Eats: PlantsOther insectsPonds, rivers and shores6 legs

The common marine caddisfly is a small, tawny insect that looks a bit like a little moth, with feelers much longer than its body. It is one of the very few insects that live in the sea. Its young grow up in rock pools by the seashore.

Lives in
The coasts of New Zealand and New South Wales in Australia, in rock pools
Length
5.3 to 5.8 mm (0.21 to 0.23 in)
males
Top speed
about 5.3 km/h (3.3 mph)
Flying, estimate
Can it hurt you?
Harmless
Harmless. It does not bite or sting.
What does it eat?
Its young eat seaweed and tiny bits of old plant and animal stuff in the rock pools.
For real!Photo of Common marine caddisfly
Picture by Steve Kerr. CC BY 4.0, via Wikimedia Commons.

How big is it?

How long is it?

Common marine caddisfly about 5.8 mm long (0.23 in)A grain of rice about 6 mm (0.24 in)A toy building brick about 3.2 cm (1.3 in)
small enough to sit on your fingernailcould fly across a whole football pitch in 71 secondsmoves 250 times its own body length every second

How big is Common marine caddisfly compared to YOU?

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How fast is it?

cool stuff

Fun facts

1

It cannot live in fresh water, only by the sea.

2

The mother lays her eggs inside a starfish called a cushion star.

3

Its young build a little tube-shaped case to live in, made of seaweed and bits of sand or shell.

4

The young grow through seven stages in the rock pools before they become grown-ups with wings.

5

Scientists first described it in 1852 from just one male.

you asked

Most asked questions about Common marine caddisfly

?Where does the common marine caddisfly live?

On the coasts of New Zealand and New South Wales in Australia. Its young live in rock pools.

?Where does the marine caddisfly lay its eggs?

Inside starfish called cushion stars.

For bug experts

Scientific name
Philanisus plebeius
Named by
Walker, 1852
Group
Other insects
Family
Chathamiidae
Classification
Insecta > Trichoptera > Chathamiidae
Lives on
Australia and Oceania

Where the facts come from

  1. Philanisus plebeius (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 Steve Kerr. CC BY 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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More from the same group: Other insects

Also at home here: Ponds, rivers and shores

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