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Sticker of Swift lousefly
Bug card No. 4259 of 4,939

Swift lousefly

Crataerina pallida
Eats: BloodFlies and mosquitoesHouses and farms6 legs

The swift lousefly is a strange flat fly that lives on swifts, the fast birds that scream over towns in summer. It spends its whole life in the swifts' nests. It drinks the birds' blood.

Lives in
Europe and Asia, in swift nests under roofs
Top speed
about 8 km/h (5 mph)
Flying, estimate
Can it hurt you?
Can bite
It is a biting fly, but it lives with swifts and hardly ever meets people.
What does it eat?
It sucks the blood of swift chicks and grown-up swifts, about 25 milligrams every 5 days.
For real!Photo of Swift lousefly
Picture by Klaus Roggel, Berlin. CC BY-SA 3.0, via Wikimedia Commons.

How fast is it?

cool stuff

Fun facts

1

Its babies spend the winter as pupae in the empty swift nest.

2

The flies hatch in spring just when the returning swifts lay their eggs.

3

It passes from the parent birds to their chicks.

4

It needs the swifts to do well, so it does little harm to the chicks' growth.

you asked

Most asked questions about Swift lousefly

?Does the swift lousefly bite people?

It is a biting fly, but it lives in swift nests and rarely meets people.

?How does the swift lousefly find swifts?

It never leaves them. It waits in the swift nest over winter and hatches when the birds come back.

For bug experts

Scientific name
Crataerina pallida
Group
Flies and mosquitoes
Family
Hippoboscidae
Classification
Insecta > Diptera > Hippoboscidae
Lives on
Europe, Asia

Where the facts come from

  1. Crataerina pallida (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 Klaus Roggel, Berlin. CC BY-SA 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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