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Sticker of Grannom
Bug card No. 0643 of 1,500

Grannom

Brachycentrus subnubilus
Eats: Nothing as a grown-upOther insectsPonds, rivers and shores6 legs

The grannom is a caddisfly, a small moth-like insect with hairy wings. Its babies grow up underwater in rivers and streams. Like many caddisfly larvae, they build little protective cases out of silk.

Lives in
Europe, in clean rivers and streams
Top speed
about 5 km/h (3.1 mph)
Flying, estimate
Can it hurt you?
Harmless
Harmless. It cannot bite or sting.
What does it eat?
Most grown-up caddisflies live only a short time and do not eat at all. The larvae find their food in the water.
For real!Photo of Grannom
Picture by Bruce Marlin. CC BY-SA 2.5, via Wikimedia Commons.

How fast is it?

cool stuff

Fun facts

1

Caddisflies are cousins of moths and butterflies, but they have hairs on their wings instead of scales.

2

Caddisfly larvae glue sand, tiny stones or bits of plants onto their silk cases to make them stronger.

3

Caddisflies only live in clean water, so finding them shows that a river is healthy.

4

People who fish make pretend caddisflies out of feathers and thread to catch trout.

5

One artist gave caddisfly larvae gold and gems, and they built sparkly jewel cases.

you asked

Most asked questions about Grannom

?What is a grannom?

It is a kind of caddisfly, a small insect whose young live in rivers and whose adults fly.

?Does the grannom bite?

No. It is completely harmless.

?Where do grannom larvae live?

Underwater in rivers and streams, inside little cases they make themselves.

For bug experts

Scientific name
Brachycentrus subnubilus
Group
Other insects
Family
Brachycentridae
Classification
Insecta > Trichoptera > Brachycentridae
Lives on
Europe

Where the facts come from

  1. Caddisfly (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 Bruce Marlin. CC BY-SA 2.5, Wikimedia Commons. The round sticker of this bug is cut from the same picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at hello@bugwiki.app and we will fix it.

More from the same group: Other insects

Also at home here: Ponds, rivers and shores