Good info for me too as a third year student , and it tells me that what I was tempted to do but had trepidation about is probably NOT right to do - reuse old/unknown-aged brood frames from a deadout of undetermined causes.
One of my two spring nuc colonies has died. About ten days ago, I was tucking my four colonies in with a last feeding and saw no activity at the door. Under the lid I found the inner cover crawling with tiny ants, and inside it looked like the whole population died in a mass event, heaped on the bottom & smelling awful. So, I figure they were dead at least a week given that plus how recently I’d seen regular traffic. All looked perfectly well during the vape treatment 3 weeks prior.
Storage was cleaned out, ostensibly from robbing after the colony began to weaken or - died suddenly? Several frames have bees in cells, head first. There were some traces of mite excrement, but not a huge amount. Some frames were moldy & I tossed those along with two plastic ones.
I moved everything across the yard and tidied up as best I could. For now, the two brood boxes and the remaining frames of otherwise nicely built combs are stacked on my side porch, protected from rain/snow and larger pests. All the points about toxic buildup plus the chance of disease weigh against reusing this equipment, except if I render the wax and then give the wooden ware a good cleaning in spring. Thoughts?
PS - I contacted my local ag extension to ask about testing, but have had no reply. Will try again.