Hydrobiosis falcis is a species of caddisfly belonging to the family Hydrobiosidae. The species was first described by Keith Arthur John Wise in 1958, and is endemic to New Zealand.
The species was identified by Wise in 1958. The species is genetically most closely related to H. styracine, and more distantly related to H. budgei, H. copis, H. johnsi, H. parumbripennis and H. umbripennis.[1]
Wise's original text (the type description) reads as follows:
Wise noted that the species could be distinguished from other Hydrobiosis species by the inner arm of each inferior appendage being much shorter than the outer arm, something not seen in H. umbripennis or H. parumbripennis.
The species is endemic to New Zealand. Specimens have been collected from Mount Taranaki, Mount Ruapehu, and near Lake Waikaremoana.[2]