| Scellus | |
|---|---|
| Scellus notatus | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Clade: | Pancrustacea |
| Class: | Insecta |
| Order: | Diptera |
| Family: | Dolichopodidae |
| Subfamily: | Hydrophorinae |
| Tribe: | Hydrophorini |
| Genus: | Scellus Loew, 1857 |
| Type species | |
| Hydrophorus spinimanus Zetterstedt, 1843 | |
Scellus is a genus of flies in the family Dolichopodidae. It is distributed in the Palearctic and Nearctic.
Males of the genus have a pair of flag-like appendages, known as "signa" (singular "signum"), that emanate laterally from between the 4th and 5th abdominal segments. These appendages are connected together by a band under the sternites, forming a U-shaped structure called the "cingulum". It has been suggested by researchers that these appendages are used for visual signalling or pheromone dispersal during courtship. The genus Hydatostega also has a cingulum, but much reduced, suggesting that Scellus and Hydatostega are closely related.