As previously mentioned in this blog Oxalic acid has received approval from the EPA for varroa control in honey bee hives. Oxalic and formic acid are naturally occurring compounds; not synthetic pesticides and are therefore considered by some as better methods for varroa control. Oxalic acid for varroa control can be applied in two ways; via a vaporizer or via a drip method. The link provided below describes the drip method. Maybe we can get beekeeper Charles to demonstrate his homemade oxalic acid vaporizer at one of the fall bee club meetings.