Bug Wiki
Sticker of Secondary screwworm fly
Bug card No. 3786 of 4,939

Secondary screwworm fly

Cochliomyia macellaria

The secondary screwworm is a blowfly with a shiny blue-green body and a red-orange head. It is drawn to dead animals and rubbish. Its maggots help clean up nature, but they can also get into the wounds of animals.

Lives in
The United States, southern Canada and the American tropics
Length
5 to 8 mm (0.2 to 0.31 in)
Top speed
about 8 km/h (5 mph)
Flying, estimate
Can it hurt you?
Dangerous: look, do not touch
It can spread germs to people and farm animals, and its maggots can get into wounds. Look, do not touch, and tell a grown-up if you see many flies near food.
What does it eat?
It feeds on dead animals and rubbish, and its maggots eat dead flesh.
For real!Photo of Secondary screwworm fly
Picture by xpda. CC BY-SA 4.0, via Wikimedia Commons.

How big is it?

How long is it?

Secondary screwworm fly about 8 mm long (0.31 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 47 secondsmoves 280 times its own body length every second

How big is Secondary screwworm fly compared to YOU?

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

How fast is it?

cool stuff

Fun facts

1

It has three black stripes down its shiny blue-green back.

2

It is called secondary because its maggots usually move into wounds after other flies have been there first.

3

It is often found at markets and slaughterhouses in warm countries.

4

It is an important clean-up worker, helping dead animals break down.

you asked

Most asked questions about Secondary screwworm fly

?What does the secondary screwworm eat?

Dead animals and rubbish. That makes it an important cleaner in nature.

For bug experts

Scientific name
Cochliomyia macellaria
Group
Flies and mosquitoes
Family
Calliphoridae
Classification
Insecta > Diptera > Calliphoridae
Lives on
North America, South America
Also known as
Secondary screwworm

Where the facts come from

  1. Cochliomyia macellaria (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 xpda. CC BY-SA 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.

Bug Wiki honey jar For grown-ups: Bug Wiki is free, with no ads and no tracking. A small tip helps keep it online.Leave a tip

More from the same group: Flies and mosquitoes

Also at home here: Houses and farms

Honey jarfor grown-ups