Urban beekeeping in New Mexico's largest city.
When I inspected my bees today I found a couple of bees with deformed wing virus. I am planning on doing the mineral oil with winter green treatment through a fogger. My questions is... How often should I treat with the mineral oil?
I wouldn't. From everything I've read mineral oil and wintergreen are not effective. I've had good results from oxalic acid vapor. Formic acid and thymol are pretty effective, though formic is apparently difficult to use with top-bar hives. You should also do a sugar shake or alcohol wash to get an accurate mite count. Here are some good articles to read.
Note: This article is a few years old and oxalic acid vapor is now approved in the US and Canada.
Thank you for your reply.