Small-headed Stonefly vs Yellow Swarming Fly
Side-by-side species comparison
| Attribute | Small-headed Stonefly | Yellow Swarming Fly |
|---|---|---|
| Scientific Name | Perlodes microcephala | Thaumatomyia notata |
| Order | Plecoptera | Diptera |
| Family | Perlodidae | Chloropidae |
| Size | 15-22 mm body | 2-2.5 mm |
| Habitat | Rivers & Streams | Grasslands |
| Diet | Predators | Predators |
| Regions | Europe | Europe |
| Conservation | Least Concern | Least Concern |
Small-headed Stonefly
A large spring-emerging stonefly found in clean upland rivers. Nymphs are predatory, feeding on mayfly and midge larvae. An important bioindicator species.
Did You Know?
Nymphs require the cleanest, most oxygen-rich water of any stonefly, making them sensitive pollution indicators.
Yellow Swarming Fly
A tiny yellow fly famous for forming enormous hibernation aggregations in buildings, sometimes numbering millions. Larvae are predatory on root aphids in grassland.
Did You Know?
Can form hibernation clusters of millions in attic spaces, with individual aggregations weighing several kilograms.