April mite check

I did a mite check last weekend. I used the whiteboard and sprayed it with some cooking oil. I think petroleum jelly probably works better but is messier and takes longer to apply. After three days I pulled out the board and observed almost no mites. I did this check on the hive that overwintered. I didn’t even test the new hive. Maybe I’ll do that one in a couple weeks.

There is one mystery about it though. There is a blank circle (lower right corner of picture) where almost nothing collected. I will inspect the hive again in a couple of weeks to see what is going on in the box. My best guess is that there is burr comb built across some frames, but I’m not sure.