My advice base from on my experience with MAQS is DO NOT USE FORMIC ACID products......PERIOD! Formic acid is extremely toxic to honey bees. Typical responses from formic acid products I have used such as MAQS is that the queen will immediately shut down and stop laying, it is not uncommon for the queen to die, the entire hive stops foraging, and about the only activity I observed was nurse bees dragging out large numbers of dead bees and larva.
I have tried MAQS twice. I followed the directions to the LETTER and applied them in low 70 to upper 60 degree temperatures. The entrance reducers were removed and an upper entrance opening for more than adequate ventilation. BOTH times my hives experienced what I consider to be excessive bee & brood kills, a couple of hive absonded and I am waiting and watching to observe if the surviving hives still have queens.
NOD customer support is of NO help and in my opinion takes a combative stand that is akin to attacking the customer and covering their corporate backside.
In my opinion and experience, I don't believe formic acid products are safe to use on honey bees as each and every time I have, the hive just stops nearly all activity other than cleaning out the dead bees and larva. No foraging or anything like that, the queens stop laying, and in more than a few cases die. I treated about 50 hives this season with these disastrous results and similar results last season but only a few hives. Fortunately I did not treat all of my hives with MAQS and the next day when I checked on the treated hives and observed the disaster that ensued, I immediately stopped and went back to OAV. I decided to give MAQS another try this season because I treated with MAQS at about 78 degrees last season thinking perhaps I treated them when it was too warm. By the way ALL of the hives that I treated with OAV are doing fantastic. I will NEVER use MAQS, Formic Pro, or any formic acid product again.........ever. The primary reason I used MAQS both times was that I commitments that did not allow me the time to do thermal or repeated OAV treatements.
I will continue on with OAV and thermal treatment.
My suspicion is that the MAQS are not being properly stored at or below 77 degrees as per NOD instructions in some cases by the retailer or perhaps the user. Storing MAQS in elevated temperatures I believe accelerates the formic acid's degradation of the paper wrappers around the MAQS and destroys the wrapper's ability to properly regulate the release of the formic acid vapor. This I believe to be the case whether or not the MAQS container has expired or not. (On edit) This may account for the wide variance in the experiences for MAQS users.
Again, I STRONGLY recommend NOT to use MAQS, Formic Pro, or any other formic acid product as there is no way to tell if they have been properly stored or not and retailers are selling them only a few weeks from the package expiration date without warning the customer about using expried MAQS. There are a more than enough Varroa Mite treatment products out there that are not nearly as harmful or destructive to your bees as well as risking the crap shoot of whether you may have purchased and improperly stored container of MAQS or use them close to or slightly after the expiration date. Would you buy personal medications or food for yourself or your family with a track record of problems like MAQS???
Repeat after me.......JUST SAY NO!