Hosea 5:12

‘Therefore am I to Ephraim as a moth,

And to the house of Judah as rottenness (decay).'

Central to the passage (see the analysis above) is a description of what YHWH is to both Israel and Judah. To Israel He is as a moth, devouring them like clothes are devoured by moths, to Judah He is like the rottenness in fruit that spreads and spreads rendering the fruit inedible (compare the similar parallel descriptions in Job 13:28). In both cases the idea is that He is slowly executing His judgment on them because of their failure in respect of the covenant.