The locusts of Joel seem strikingly parallel with those of John’s apocalyptic vision. Why does e-watchman on the one hand identify the locusts of Joel as the future 8th king that devastates God’s people, and the locusts of Revelation as the kings of God’s kingdom?
The prophecy of Joel and Revelation both use locusts to symbolize armies of men. However, that’s where the similarity ends.
Here are a few dissimilarities: The prophecy of Joel not only depicts the invading army as a plague of devouring locust, but also they are likened to caterpillars and cockroaches. The devouring insects could not possibly represent God’s people, as the Watchtower insists. The obvious reason being that God’s people are the victims of the insect onslaught. Not only that, but Joel indicates that Jehovah intervenes to save his people from the plundering pest by driving them into the sea. (For a detailed discussion of the prophecy of Joel see the essay: Day of the Locust Attack)
Elsewhere in the Hebrew prophecies locusts are used to symbolize enemy armies. For example, the prophecy of Nahum likens the Assyrian army to locusts: “As for the locust species, it actually strips off its skin; then it flies away. Your guardsmen are like the locust, and your recruiting officers like the locust swarm. They are camping in the stone pens in a cold day. The sun itself has but to shine forth, and away they certainly flee; and their place is really unknown where they are.”
On the other hand the locust-like men symbolized in the 9th chapter of Revelation are under orders to torment the people of the world who do not have the seal of God. This is the exact same work the “two witnesses” in the 11th chapter of Revelation do, which is to say they preach a message of doom that torments the world. In view of the fact that the locusts are wearing crowns it is evident that they are the sons of kingdom, who at that point will have been given the kingdom and so will have full authority to execute Jehovah’s judgments upon the earth.