Strong Microbials Inc is working on development of a biological product to control Varroa destructor mite. Our current stage is registration with Environmental Protection Agency (EPA). Although the results are very promising, the sale of this product can start only after registration is complete.
At the current moment, an effective and all-natural/non-chemical way to control Varroa destructor is with heat. Please check out this link to Bee Hive Thermal Industries and their product the Mighty Mite Killer https://www.beehivethermalindustries.com
BioVar -- Biological Control of Varroa destructor mite
BioBeetle -- Biological Control of Aethina tumida small hive beetle