I've read adult males often live for just a single day. So if you find one in the late afternoon it may indeed be dying...without mites or other factors necessarily contributing to the process.

I found a female once in the late afternoon (attached via her ovipositor to a flower head) that was very lethargic...almost life-less.

Although somewhat similar, they don't look like the varroa images I've seen. I notice another diferently-shaped mite (or something), a bit out of focus, is perched below the two flat mites.

Okay, now that I have seen the prior post and realize what this is, let me indicate that I see what might be *a* mite on the back below the elytra.