The pallid-winged grasshopper (Trimerotropis pallidipennis) is a common grasshopper of the family Acrididae, native to the deserts of western North America. They are more active during the summer months, and their pale, mottled coloration makes them hard to see against surfaces such as the granite often found in the gravel of dry river beds. They grow to be 37 mm (1.5 inches).
In 1998, following a warm and wet monsoon season in the Phoenix Metro Area and an unusually warm and wet El Nino that affected the west coast of the United States; The PW Grasshoppers spawned and swarmed the Phoenix Metro Area. Experts following the swarm estimated 20-30 grasshoppers for every square foot of land in the Phoenix Metro Area. Several business remained closed for several days and traffic accidents severely increased during the time. Early mornings saw the worst problems due to the fact that the grasshoppers would rest in any area that was not high in traffic. When morning Rush Hours began, clouds of grasshoppers could be seen in the sky.