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pipette with essential oil


August 7, 2019

There’s a thread running through all our work, and that’s this skill we have of taking research from some of the best minds in bee science and weaving it into our own work. This way we know that our ideas, no matter how brilliant, aren’t just ours — they’re backed up by the work of some of the best minds around.

We’ve mentioned Peter Kevan before, since his research was so influential in our early explorations. We’re leaning on it even more heavily now, as we begin to determine exactly the right essential oils and percentages that will be safe for bees but adverse for mites.

And Peter Kevan has been focusing on the efficacy and toxicity of essential oils for decades:

However, there must be a balance between toxicity to hive pests and toxicity (safety) to the bees. We focused on adult bee toxicity when testing ten products: cineole, clove oil, formic acid, marjoram oil, menthol, oregano oil, oxalic acid, sage oil, thymol, and wintergreen. Each product was tested at several concentrations in a sugar syrup fed to bees over several days, and dead bees were counted daily. Oxalic acid was the most toxic of the products tested. Menthol and cineole had mortality levels no different from controls fed plain syrup after 8 days of treatment.

We’ll start with Peter’s essential oil testing percentages and continue testing in increments down from those percentages. We want the minimum amount necessary to be effective, so we can be absolutely sure it’s bee friendly.

And now that we’re moving from a liquid to a fondant reward solution, what was relatively straightforward with the oil solution needs more refining. The past couple weeks, Jim has been working with a fantastic chemist at Bayer named Mike Neunam, who’s helping us determine the best ways to add essential oil to our fondant.

Mike suggests mixing by volume rather than by weight, so we’re sure to get the same result every time. It’s these kinds of Science Things that seem so obvious if you’re a researcher, but that we furiously write down in our notebooks. He suggests we mix a small amount of lecithin with the oil, because lecithin attracts both water and fat and is therefore superb at smoothing textures, emulsifying, and homogenizing liquid mixtures.

With the fondant formula nearly complete, Jim is writing up a test protocol for the first test. He’s mixing the UV dye into the new, water-based red dye to prepare for testing (fingers very tightly crossed the bees don’t hate the water-based dye). Mitch will send new wicking felt to Jim, and Carissa and Joe will ship out the lecithin and the lemongrass and peppermint oils to Jim.

We have to say...everything smells really good right now.