Concise Bible Dictionary:

This is supposed to be the “hedge-chafer,” a species of locust. It “spoileth [or spreadeth itself out] and fleeth away.” It devours much herbage, and is used as a figure of the enemies that would destroy Nineveh (Nah. 3:15-1615There shall the fire devour thee; the sword shall cut thee off, it shall eat thee up like the cankerworm: make thyself many as the cankerworm, make thyself many as the locusts. 16Thou hast multiplied thy merchants above the stars of heaven: the cankerworm spoileth, and flieth away. (Nahum 3:15‑16); Joel 1:44That which the palmerworm hath left hath the locust eaten; and that which the locust hath left hath the cankerworm eaten; and that which the cankerworm hath left hath the caterpiller eaten. (Joel 1:4); Joel 2:2525And I will restore to you the years that the locust hath eaten, the cankerworm, and the caterpiller, and the palmerworm, my great army which I sent among you. (Joel 2:25)). The same Hebrew word is translated Caterpillar in Psalm 105:3434He spake, and the locusts came, and caterpillers, and that without number, (Psalm 105:34) and Jeremiah 51:14, 2714The Lord of hosts hath sworn by himself, saying, Surely I will fill thee with men, as with caterpillers; and they shall lift up a shout against thee. (Jeremiah 51:14)
27Set ye up a standard in the land, blow the trumpet among the nations, prepare the nations against her, call together against her the kingdoms of Ararat, Minni, and Ashchenaz; appoint a captain against her; cause the horses to come up as the rough caterpillers. (Jeremiah 51:27)