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Sticker of Elm seed bug
Bug card No. 1537 of 4,939

Elm seed bug

Arocatus melanocephalus
Eats: PlantsTrue bugs and cicadasHouses and farms6 legs

The elm seed bug is a dark red bug with a black head and an orange belly. It lives on elm trees. When it is bothered it gives off a strong smell, a bit like bitter almonds.

Lives in
Europe and western Asia, and now also western North America, on elm trees and sometimes inside houses
Length
8.4 mm (0.33 in)
Top speed
about 0.17 km/h (0.11 mph)
On foot, estimate
Can it hurt you?
Harmless
It does not bite or sting. It just smells bad if you squash it, so leave it be.
What does it eat?
It lives and feeds on trees such as elm, poplar, plane trees, oak and alder.
For real!Photo of Elm seed bug
Picture by This image is created by user B. Schoenmakers at Waarneming.nl , a source of nature observations in the Netherlands.. CC BY 3.0, via Wikimedia Commons.

How big is it?

How long is it?

Elm seed bug about 8.4 mm long (0.33 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 run across a dinner table in 21 seconds

How big is Elm seed bug compared to YOU?

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How fast is it?

cool stuff

Fun facts

1

It is about 8 millimetres long, roughly the size of a sunflower seed.

2

Its smell comes from small openings between its second and third pairs of legs.

3

In hot summers in northern Italy, lots of them crawl into buildings, maybe to escape the heat.

4

It became rarer in Europe when a tree disease killed many elm trees.

5

It reached North America in the 2000s and now lives in places like Washington, Oregon and Colorado.

you asked

Most asked questions about Elm seed bug

?Is the elm seed bug harmful?

No. It does not bite or sting, but it can be a nuisance when many come indoors and it smells when squashed.

?Why are elm seed bugs in my house?

In hot summers they come into buildings, maybe to hide from the heat.

?What does the elm seed bug smell like?

A strong, unpleasant smell a bit like bitter almonds.

For bug experts

Scientific name
Arocatus melanocephalus
Named by
Fabricius, 1798
Group
True bugs and cicadas
Family
Lygaeidae
Classification
Insecta > Hemiptera > Lygaeidae
Lives on
Europe, Asia, North America

Where the facts come from

  1. Arocatus melanocephalus (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 This image is created by user B. Schoenmakers at Waarneming.nl , a source of nature observations in the Netherlands.. CC BY 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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