Matthew Poole and continuators on Joel 1:4

4 That which the palmer-worm hath left, hath the locust eaten; and that which the locust hath left, hath the canker-worm eaten; and that which the canker-worm hath left, hath the caterpillar eaten.

Four sorts of Insects pernicious to all sorts of Trees, Corn and Herbs, are here mentioned, which did succeed each other, and devouted all that might be a future support to the Iewes, whence ensued a grievous famine for four years together, say the Iewish Interpreters, though there is no cogent reason in what they mention for proof hereof. These insects might in the same year succeed each other, the one as is usual might come sooner, the rest successively, each in its season, and so spoil the springing of all things, which they did (I do believe) really, and though these might be Emblems of some future devastation, yet it seems most agreeable to reason, and the Context, that there should really have been such caterpillars, and other vermine, and that they did devour all that was green; and though this is no where else mentioned, as I remember, in the sacred History, yet it is likely 'twas done, as here told, and as so done was a figure of some greater devastation made by Forreign Powers, as by Tiglath-Pileser, Salmaneser, Sennacherib and Nebuchadnezzar.

Marginal references: Heb. the residue of the palmer-worm.