The Beeman

A well known commercially available general purpose essential oil product for bees that is similar to the following recipe claims many benefits even though many of those claims have yet to be proven. But it seems to work well with my bees. They just love it
It`s the spearmint Oil that works all the magic and the Lemon grass Oil that encourages them to take it!The University Of West Virginia

has been doing a lot of research It to the effects of Varroa Mites on honey bees and the effects of Spearmint and Lemon Grass and the effect it has improving the Bees own immune system.
http://www.sciencedaily.com/releases/2007/05/070518144833.htm5 cups water
2 1/2 pounds of sugar
1 teaspoon lecithin granules (used as an emulsifier)
15 drops spearmint oil
15 drops lemongrass oil

Bring the water to a boil and stir in the sugar until it is dissolved. Once the sugar is dissolved remove the mixture from the heat and quickly add the lecithin and after cooling for a bit, then essential oils. Stir the mixture thoroughly. This solution should have a strong scent and not be left open around bees. Cool before using.

The above is a base mix you add to 1:1 Sugar Syrup

ADD 5ml per Litre

To use as a drench in a spray bottle I add 20ml Per Litre

You can use it instead of smoke and just spray the bees it keeps them calm on the frame.
Be careful when there is no nectar flow it can encourage robbing.

I find to get the best result give it to your bees once a week for 3 weeks in a row.