Jamieson, Fausset and Brown on Exodus 10:13-19

13-19. the Lord brought an east wind--The rod of Moses was again raised, and the locusts came. They are natives of the desert and are only brought by an east wind into Egypt, where they sometimes come in sun-obscuring clouds, destroying in a few days every green blade in the track they traverse. Man, with all his contrivances, can do nothing to protect himself from the overwhelming invasion. Egypt has often suffered from locusts. But the plague that followed the wave of the miraculous rod was altogether unexampled. Pharaoh, fearing irretrievable ruin to his country, sent in haste for Moses, and confessing his sin, implored the intercession of Moses, who entreated the Lord, and a "mighty strong west wind took away the locusts."