Rev 9:3

“In the locusts he signifies spiritual and adversarial powers that we see flying around in the air in the manner of locusts for the purpose of harming humankind.”

“The "locusts" signify those who come forth from the smoke. For, like smoke, the heretics desire to rise high, since by their teachings they strive for positions of eminence, yet, again like smoke, they are dissipated. We read of this smoke, for in the person of those who are evil it was said, "Smoke is the breath in our nostrils, and reason is the sparks for moving our heart." When the impious are said to strive by sin against wisdom, that is, against the Lord Jesus Christ, they are also described as fighting against his church, harming it by their malicious mouth, while they are hindered from harming the green grass and trees.”

“And out of the smoke came forth locusts upon the earth. Just as the saints are the body of Christ, and members from a member, so also the members of the flesh of the dragon are joined together, one being born from another, and the smoke of heretical blindness generates the pride of the wicked, harming them with its mouth. But those who are shaken off by pride do not forsake earthly things. For even the smoke from which they are born, though it seeks high places, always fails in itself.”

“And power was given to them, etc. Heretics are compared to opposing powers, seemingly innocent in appearance, but holding poison within their hind parts.”

“And from the smoke there came out locusts upon the earth. It is fitting for the heretics to be represented by locusts, for just as we see locusts, neither flying perfectly like birds nor walking by steps, but making leaps, chew up the crops of the earth, so do the heretics, having neither the flight of full knowledge nor the walk of perfect work, but only moved by the leaps of pride, kill the souls of the wicked by preaching unheard-of things. So locusts come out of the smoke when heretics are born from heretics. And power was given to them, as the scorpions of the earth have power. The power of scorpions is in the tail, which is at the end of the body: so is temporality left behind as it withdraws from itself; for everything that passes is, as it were, behind, while everything that remains is before. So the locusts receive power to hurt as the scorpions of the earth because the heretics, sustained by temporal powers, hurt only with what is behind.”

“And from the smoke "locusts came out onto the earth". I believe the term "locusts" [ἀκρίδες] refers to worms, about which Isaiah says: "Their worm shall not die, and their fire shall not be quenched," (Isa. 66:24; Mark 9:48) possibly calling the worm the biting of the soul and the relentless and creeping pain. And it was said that "they were given authority", just "as the scorpions of the earth have authority".”

“But the sun now shone out a little, and, lo! I see a mighty beast like a whale, and out of its mouth fiery locusts proceeded.”