BugWise

What do stoneflies look like?

An example of a stonefly. Photo: M Bulbert © Australian Museum.

Stonefly. Illustration: A Howells © Australian Museum.

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.

What do stoneflies do?

• 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 looks similar?

• 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.