All about invertebrates

Scorpion-flies and hanging-flies (Order Mecoptera)

What do scorpion-flies and hanging-flies look like?

An example of a hanging fly An example of a hanging fly. Photo: © B Hulbert.
Hanging-fly Hanging-fly. Illustration: A Howells © Australian Museum
Size:
Wingspan up to 50 mm across.
Body:
Column-like or widest at wing attachment ('wide shoulders') tapering past this point.
Head with a beak-like extension.
Appears soft and fragile.
Antennae:
Thread-like, with many segments and longer than half their body length.
Eyes:
Large, bulging and well separated.
Mouthparts:
For chewing or munching.
Located at the tip of beak-like extension of the head.
Held downwards at rest.
Wings:
Two pairs if present (though rarely absent).
Both pairs are similar in size, membranous, clear, and have numerous cross-veins forming mainly rectangular cells.
At rest most hold their wings tent-like above their body though some species overlap them.
Limbs:
Six legs, very long and slender.
Have large spines at joints.
Often have large claws for grabbing onto prey and plants.
Abdomen tip:
Cerci (tails) absent.
Males have claspers, which are used to hold onto the female during mating.
In some groups the abdomen is raised similar to the stinging tail of a scorpion hence the common name scorpion-fly.

Where are scorpion-flies and hanging-flies found?

  • Usually around moist environments or adjacent to open water. Some however are found in drier habitats.
  • On herbs and low shrubs that have many leaves.
  • Occasionally amongst tall grasses or on flower heads.
  • One wingless species can be found on snow (Tasmania only).

What do scorpion-flies and hanging-flies do?

  • They are solitary.
  • When disturbed they fly away, flying only in short bursts.
  • They tend to be weak, slow, flapping fliers.
  • Hanging-flies hang from plants by their forelegs waiting to catch prey with their hind legs.
  • Both hanging-flies and scorpion-flies tend to be predators preying on flies, moths, bees, spiders and various larvae. Some are also scavengers taking nectar as they hunt.
  • They are active during the day.

What looks similar?

  • Lacewings can have a beak-like extension of the head but it is never as long as you would see in a hanging-fly or a scorpion-fly. Lacewings are distinguished by the forked veins along the margins of their wings.
  • Alderflies/Dobsonflies are easily distinguished as they lack a beak-like extension of head.
  • Crane flies (order Diptera, family Tipulidae) are often confused with hanging-flies as they have long legs and have a habit of hanging on plants. Craneflies can be distinguished by only having one pair of fully functional wings.
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