Identification of stoneflies
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.