Brushleg Mayfly vs Giant Stonefly
Side-by-side species comparison
| Attribute | Brushleg Mayfly | Giant Stonefly |
|---|---|---|
| Scientific Name | Isonychia bicolor | Pteronarcys californica |
| Order | Ephemeroptera | Plecoptera |
| Family | Isonychiidae | Pteronarcyidae |
| Size | 12-18 mm | 30-50 mm body |
| Habitat | Rivers & Streams | Rivers & Streams |
| Diet | Omnivores | Herbivores |
| Regions | North America | North America |
| Conservation | Least Concern | Least Concern |
Brushleg Mayfly
A large, fast-swimming mayfly with forelegs fringed with bristles for filter feeding. Nymphs inhabit swift riffles of large streams and rivers.
Did You Know?
Unlike most mayflies, nymphs crawl out of water onto rocks to emerge as adults rather than hatching at the surface.
Giant Stonefly
Large aquatic insects whose nymphs require pristine, cold, oxygen-rich streams. Adults are poor fliers and stay near water. Important food source for trout.
Did You Know?
Stonefly nymphs are so sensitive to water pollution that their presence is used by scientists as a living indicator of water quality — no stoneflies means polluted water.