On a German beekeeper and scientist convention the following has been presented. Some studies on neonics and varroa. Findings:
Insecticides affect the population dynamics of mites!
Insecticides cause stress!
Significant effects in the fall if varroa + pesticides
varroa load is higher in the A and B group (which was fed with sublethal doses of neonics
Feeding of neonicotinoids leads to the reduction of hemocytes.
Neonics affect wound closure (wound may not heal well).
For thiacloprid this effect occurs only after high doses. For Clothianidin the effects occur after low doses