We typically use Formic pro as our summer treatment, this is because you can use Formic Pro while you have honey supers on your hive. We had tested this hive and the test determined that we need to treat. For Formic Pro, you want at least the first 3 days to be 85 degrees F or below. Once the treatment is complete, we will test again.
We test again to determine how well that treatment worked. Most treatments are temperature sensitive. Additionally, testing prior to treatment we know the mite count we started with and mite count after treatment. If you don’t test and just treat, you have no idea where your mite counts are at.
For example: If I test and I have 8 mites, I treat and now I’m at 4 mites. The treatment worked, but didn’t drop to or below the mite threshold of 3. I am still at a high mite count and I would need to treat again. Without testing before and after, I don’t know how bad the mite problem actually is. In this example, if I never tested before and after, I still have a mite problem and don’t know it.
Rule of thumb: Test each month, treat when needed, test after treatment.