When we first mentioned that we would be posting detailed follow-ups of the talks we attended at the Michigan Beekeepers Association Spring 2017 Conference, there was a particular request from a reader for a report on Dr. Seeley’s presentation on plastic foundation, Plastic Foundation: Good for Beekeepers? Good for Bees?, and the interesting thing we non-users learned. Months later we finally present that report.
Plastic foundation is food grade plastic covered in a very thin layer of beeswax1. It is available in two forms, as sheets to be inserted into wooden frames just as wax foundation is and as complete one-piece plastic frame including foundation. The general conclusion is that it has advantages for the beekeeper.
- Frame assembly is made simpler, especially if already part of a one-piece frame.
- The plastic back makes strong combs that do not blow out in a centrifugal extractor.
- It is better for pre-supering.2 Practiced in apiaries that are hard to visit frequently, this is the procedure of adding supers of undrawn comb far in advance of a nectar flow. Wax foundation thus used gets dry and nibbled.
But Dr. Seeley had questions about disadvantages for the bees.
- Does it hinder comb building?
- Does it reduce honey production?
- Does it interfere with waggle dancing?
The answer to the first two is ‘yes, but there is a fix’, the first part of which is to paint a thicker layer of beeswax on the plastic sheet3. Dr. Seeley suggests using disposable foam brushes. That may suffice but one can also try to establish ideal conditions for comb building: a heavy nectar flow and hive full of brood and nectar. The middle-aged bees, which are the nectar-receivers and wax-producers, will be strongly motivated to draw out comb to make room for the incoming flood.
That leaves the question of whether or not it is a fully suitable substrate for waggling. And here comes the information we found so interesting, if only because of the many hours spent so long ago surrounded by electronics equipment in physics labs . The comb consists of relatively thin cell walls rising from the foundation and having a thicker rim at the top. A waggle-dancing bee shakes this rim to attract followers, producing vibrations centering around two frequencies, 15 Hz with its body and 250 Hz with its wings. Followers of the dance detect vibrations in air and through the comb with the subgenual organ in each leg, seemingly over a greater distance on open comb than on closed comb.
In one of his few experiments not involving watching individually marked bees in an observation hive placed in a contrived environment, Dr. Seeley used an oscillator in a lab to find that comb on plastic foundation dampens the 250 Hz signal but not the 15 Hz component.4 But then he returned to his habitual tricks to observe in the field that there was no difference in recruiting effectiveness for any of wax foundation, plastic foundation in wooden frame, and one-piece plastic frame with foundation.
One question raised by the audience that was not investigated was whether the plastic outgassed significantly to harm the bees or build up in the wax. But then Dr. Seeley’s focus is honeybee communication rather than general health and that investigation would have required an entirely different array of laboratory equipment.
In conclusion plastic foundation has advantages for the beekeeper and, even with different acoustic properties than wax, no disadvantages for the bees if the beekeeper makes an effort to get them to draw comb upon it.
1Very, very thin. Jokes were made about the nearly monomolecular, almost homeopathic thinness of the wax coating.
2An audience member pointed this out.
3The same audience member pointed out that a version with thicker wax coating is available.
4It is common for higher frequencies to be more attenuated than lower due to acoustic heating of the medium.