Started three new hives this year to add to my present three. Two were packages and one wild caught swarm. Have had and lost hives to SHBs and have tried everything I could find. This year I started feeding early even before I got the packages or the wild swarm. Not trying to start a debate, or convince anyone of anything; just stating what I did. I feed with community feeders, (as in hanging chicken water buckets purchased from Farm Store) so my present hives received the same treatment at the new hives. When mixing the sugar water, 1lb sugar to 1lb H2O, I added essential oils: To 1/4 cup of nuked honey I added: 2 drops each of, Clove Oil, Oregano Oil, Tea Tree Oil, Lemon Grass Oil, and Eucalyptus Oil. (The honey will allow you to mix the oils with water). The new hives used this draw out cone, and the old hives fed, stored, and drew cone. I AM NOT SAVING ANY HONEY THIS YEAR, BUT AM TRYING TO GET ALL DOUBLE DEEP HIVES!
I have had terrible luck with SHBs, but as of today I have not seen one beetle in any of my 7 hives. NOT ONE SINGLE BEETLE! I had SHBs Winter over that I saw when I opened the hives this year, but they are GONE! I mean NOT ONE, not even a trace.
IT DOES NOT seem to have any effect on the bees as they are going GANG BUSTERS.
Take it for what it is worth, but I will continue to figure which Oil is the one doing all the good. I do use Essential Oils Myself daily.