Jamieson, Fausset and Brown on Hosea 5:12

12. as a moth--consuming a garment (Job 13:28; Psa 39:11; Is 50:9).

Judah ... rottenness--Ephraim, or the ten tribes, are as a garment eaten by the moth; Judah as the body itself consumed by rottenness (Pr 12:4). Perhaps alluding to the superiority of the latter in having the house of David, and the temple, the religious center of the nation [Grotius]. As in Ho 5:13, 14, the violence of the calamity is prefigured by the "wound" which "a lion" inflicts, so here its long protracted duration, and the certainty and completeness of the destruction from small unforeseen beginnings, by the images of a slowly but surely consuming moth and rottenness.