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Sticker of Fall webworm
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Fall webworm

Hyphantria cunea
Eats: PlantsMothsGardens and meadows6 legs

The fall webworm is a fluffy white moth, but it is famous for its caterpillars. In late summer they spin big messy silk tents at the tips of tree branches. Hundreds of hairy caterpillars live and eat together inside.

Lives in
North America, and now also Europe and Asia, on trees in gardens, parks and woods
Wingspan
3.5 to 4.2 cm (1.4 to 1.7 in)
Top speed
about 14 km/h (8.7 mph)
Flying, estimate
Can it hurt you?
Harmless
Harmless. The caterpillars have prickly hairs, so it is best to watch them and not pick them up.
What does it eat?
The caterpillars munch the leaves of almost any leafy tree, from walnut and elm to fruit trees. They have been found eating more than 600 kinds of plants.
For real!Photo of Fall webworm
Picture by TampAGS , for AGS Media. CC BY-SA 3.0, via Wikimedia Commons.

How big is it?

How wide are its wings?

Fall webworm wings about 4.2 cm tip to tip (1.7 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)
wings as wide as 7 grains of rice in a rowcould fly across a whole football pitch in 27 seconds

How big is Fall webworm compared to YOU?

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

How fast is it?

cool stuff

Fun facts

1

The caterpillars wiggle all together at the same moment, like a dance. Nobody knows exactly how they keep in time.

2

The mother moth covers her eggs with hairs from her own tummy to protect them.

3

The silk tent keeps the caterpillars warm, helps them grow faster and hides them from hungry birds.

4

It came from North America and travelled to Europe and Japan in the 1940s.

5

It spends the winter as a dark brown pupa in a thin silk cocoon, hidden in bark and fallen leaves.

you asked

Most asked questions about Fall webworm

?Do fall webworms kill trees?

No. They can eat a lot of leaves, but a healthy tree grows them back.

?What does the fall webworm moth look like?

It is a small hairy moth, mostly white, sometimes with dark spots, and its front legs have yellow or orange patches.

?What do fall webworms eat?

The caterpillars eat the leaves of many trees, like walnut, elm, hickory, maple and fruit trees.

For bug experts

Scientific name
Hyphantria cunea
Group
Moths
Family
Erebidae
Classification
Insecta > Lepidoptera > Erebidae
Lives on
North America, Europe, Asia

Where the facts come from

  1. Fall webworm (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 TampAGS , for AGS Media. CC BY-SA 3.0, 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: Moths

Also at home here: Gardens and meadows