Adam Clarke on Joel 2:25

I will restore - the years - It has already been remarked that the locusts not only destroyed the produce of that year, but so completely ate up all buds, and barked the trees, that they did not recover for some years. Here God promises that he would either prevent or remedy that evil; for he would restore the years that the locusts, cankerworm, caterpillar, and palmerworm had eaten.