Mayflies are important as macroinvertebrates of aquatic ecosystems and are reliable bioindicators of water quality. Most mayfly nymphs feed by scraping algae from underwater rocks or by extracting food particles in the littoral and benthic zones of the water bodies. The mayfly Povilla (Languidipes) taprobanes originally described from Sri Lanka was observed in plastic lined ponds in coastal Karnataka. Not only, this is the first report of the species from Karnataka, but the unique case making behaviour of this species is also described for the first time. Additionally, the species was found damaging plastic tarpaulins of 750 gsm thickness used as lining for water storage in the tank by chewing. This chewing behaviour was responsible for damage of plastic sheets leading to water leakage. The possible loss caused and a need of alternate strategies to store water is discussed.