Of all feeding systems we have tried, this one is the best. The oils are delivered directly to the brood with large amounts of syrup consumed by the bees. We feel this method will work during honey flows, by directing the treated syrup directly to the brood area, thus avoiding replacement by incoming nectar. A preliminary test done this fall indicated this method will work. The only problem we found with this system is that the bees chew up the wick faster than capillary action can replenish the syrups. We are currently looking for a material that the bees can't, or won't, chew up.
In our earlier experiments we found that some hives were reluctant to take some essential oil syrups while others would readily take them. After feeding several different essential oils, we found lemongrass oil to be the best for stimulating the bees. The bees take this oil extremely fast compared to other oils and syrups, and would seem to fight to get to it. Dr. Amrine looked up the chemical makeup of this oil and found that it contains some of the same natural pheromones that bees use to attract workers (such as geraniol). We mixed it with spearmint, since this oil has been giving us consistent good results. Normally, bees are repelled by spearmint if it exceeds 0.75 ml per quart. We found that most hives readily take this mixture at rates of 1 -2 ml of spearmint-lemongrass per quart.