#hydrellia

Another shore fly species, but this one is endemic to New Zealand. The first hostplant for the species was only identified in 2012, but the text of that paper is behind a paywall.

There are more than 240 described species in the genus. Some Hydrellia species are being investigated as biocontrols of Hydrilla verticillata in Florida - two native and one each from Pakistan and Australia. Hydrilla verticillata is a horrendously invasive aquatic plant, but success with the flies has so far been limited - possibly because the flies are themselves being parasitised by a native wasp.

An Ephydrid fly found in New Zealand and SE Australia. A pasture pest, because the larvae are leaf miners in grass. Don't ask me why they were so high up on Mt Ruapehu - there certainly wasn't any grass.