Today at Bugs Below Zero we are highlighting the Insect Order Plecoptera! Also known as stoneflies, these aquatic insects are important creatures in aquatic ecosystems. To learn more about the order Plecoptera read the blog post linked below! Stay tuned for our next Insect Highlight…Chironomidae!
Written by: Hope Chappuis
Stoneflies are a covert insect in the order Plecoptera that can be hard to spot. Trout anglers are especially excited when they identify stoneflies as these insects are often a sign that trout - and good trout habitat - are nearby. Stoneflies are an excellent indicator of good water quality as they thrive in clean and cool water with stable temperatures. Despite their name, stoneflies, these insects are typically not excellent flyers.
How do I identify a Stonefly?
Stonefly nymphs (immature stages) can be identified by the two tarsal claws on the end of each of their legs. Tarsal claws help these insects clasp rough surfaces. Plecoptera are also known for their two segmented caudal filaments which are tail-like projections that extend from the end of the insect’s abdomen. The more mature nymphs can be easier to identify because they have wing pads on the thorax. The shape of these wing pads can be used to determine between families.
Where can I find Stoneflies?
Plecoptera are greater in abundance and diversity in fast flowing water that is well oxygenated. Their preferred habitats are cobble, leaf packs, and woody debris.
Quick-fire Fun Facts
Plecoptera are the most pollution sensitive aquatic insects. They are found solely in running water because of its high oxygen content.
Drumming as a pick-up line? Adult stoneflies (both male and female) use drumming to attract mates. They strike their abdomens against substrates like logs which produce a set of audible pulses and pauses that can be heard by humans and recorded. Each species has a unique vibration pattern.
The nymphal stage is long for stoneflies and can last anywhere from 6 months to 3 years, but adults only live 1-4 weeks.