Varroa checks

[Bobbee]

I just lost my first two colonies it is looking like to varroa. Moisture may have played a part however varroa mites I now believe were the main cause. Varroa and my not keeping their numbers down.I plan on being much more aggressive with checking and treatment next year even if I have to walk the 10 miles to the hives.
At the moment I have a couple of  questions.
 How soon should I check for mites after installing a 5 frame nuc?
Is it a bad idea to just assume mites and treat with OA ?I realize if I don't do a mite wash  I wont know if one colony has better varroa hygiene than the other. At this point I do not care.
 I just want to keep them alive and healthy.

[The15thMember]

I lost one of my colonies to varroa my first year, and it taught me a lot about managing the mites.  Like most things in beekeeping, a lot of this comes down to personal preference and your bees in your environment.  I usually only treat when I see high numbers, but I know plenty of people who treat on a schedule.  Neither is wrong.  I personally feel it's a good idea to check mite levels periodically, even if you are planning on treating regardless, just so you can gain a feel for what your mite levels are like at different times of the year, and to make sure your treatment is working sufficiently.  I usually do sugar rolls (I prefer that method to the alcohol wash) at the beginning of the spring season, before my major honey flow, after my major honey flow/before any fall treatments, and after any fall treatments, and of course any time I think a colony has a high mite load (seeing lots of pulled pupae, bees that are shiny or with messed up wings, colony not building up well, etc.).  If it were me, I'd let the nuc get good and settled in, make sure you have an established laying queen, and then check for mites to know your baseline.  Whatever you do after that, I think, is up to you, as long as you do something.  Good luck next season, and don't be too hard on yourself about first year mistakes, we all make 'em.