From the PNAS paper about which the NatGeo article was written:"... a molecular phylogeny ... reveals that this amphibious lifestyle is an example of parallel evolution and has arisen from strictly terrestrial clades at least three separate times in the genus starting more than 6 million years ago, before the current high islands existed.....Why and how Hyposmocoma, an overwhelmingly terrestrial group, repeatedly evolved unprecedented aquatic species is unclear..."That makes it even more bizarre, in my opinion.
They must have evolved really fast sense it’s in Hawaii (a relatively new island) or maybe it has a relative on a continent
It sure looks an awful lot like a caddisfly. It also says on wiki-P that this group eats snails.
But its adult forum is completely terrestrial?