Plecoptera Click to enlarge image
Stonefly (Order Plecoptera) Image: Andrew Howells
© Australian Museum

What do stoneflies look like?

Size:

  • 4 mm - 60 mm in length.
  • Wingspan 10 mm - 110 mm.

Body:

  • Column-like and often flattened.
  • Appears soft and fragile.

Antennae:

  • Thread-like, with many segments.
  • Often longer than half body length.

Eyes:

  • Bulging and well separated.

Mouthparts:

  • For chewing or munching.
  • Held in front at rest.

Wings:

  • Two pairs if present.
  • Both pairs membranous and clear.
  • Most species have moderate number of wing cross-veins that form long rectangular cells.
  • Few species have numerous cross-veins and cells.
  • Hindwings are shorter and wider than the forewings.
  • At rest, wings overlap and are held flat over body or often curving around the abdomen.
  • Generally cover the abdomen though a few species have short wings.

Limbs:

  • Six short legs.
  • Fore- and midlegs held out from body and bent at 'elbows'.

Abdomen tip:

  • Two moderately long cerci (tails) with many segments.

Where are stoneflies found?

  • Close to creeks or rivers generally on adjacent vegetation, or behind bark and logs.

Stoneflies behaviour

  • They are solitary.
  • When disturbed they are reluctant to fly: often running quickly to cover, raising wings to appear larger or flying away to land again soon after.
  • They are weak flapping fliers, only flying in short bursts.
  • Most use colours and patterning to blend in with their surroundings. Though some large alpine species have brightly coloured wings.
  • They feed on plant debris, algae, lichen, rotting wood and bark.
  • They are active during either the day or night; night active species are attracted to lights.

What animals look similar to stoneflies?

  • Alderflies or dobsonflies can look a lot like stoneflies. However they can be distinguished by the fact most hold their wings tent-like, they do not have cerci (tails), and they hold their legs underneath their body.