Gastrimargus musicus

Gastrimargus musicus, the yellow-winged locust or yellow-winged grasshopper, is a common grasshopper in Australia. It only displays its yellow back wings in flight, when it also emits a loud clicking or crackling sound. When swarming, the adults become dark brown.
They are sometimes confused with the Australian plague locust, though the yellow winged locust is "stouter and larger". In north Australian savannas it remains a solitary species.
Adult females range from 35 to 50 mm, while males are smaller ranging from 25 to 35 mm.