A.T. Robertson Commentary Revelation 9:3

"And out of the smoke came forth locusts upon the earth; and power was given them, as the scorpions of the earth have power." — Revelation 9:3 (ASV)

Locusts (ακριδες). Also verse 7 and already in Mt 3:4; Mr 1:6 (diet of the Baptist). The Israelites were permitted to eat them, but when the swarms came like the eighth Egyptian plague (Exodus 10:13ff.) they devoured every green thing. The smoke was worse than the fallen star and the locusts that came out of the smoke were worse still, "a swarm of hellish locusts" (Swete).

The scorpions (ο σκορπιο). Old name for a little animal somewhat like a lobster that lurks in stone walls in warm regions, with a venomous sting in its tail, in N.T. in Lu 10:19; 11:12; Revelation 9:3,5,10. The scorpion ranks with the snake as hostile to man.