The Classroom
The Classroom – July 2024
Q Stopping sugar water fermentation
Nelson Pomeroy, in his book “Bumblebee Keeper” describes how Koppert solved the problem of fermenting syrup a long time ago: 0.05% potassium sorbate. The explanation is on page 108.
Chris May
Australia, April
A
Thanks for the information. I confess that I am answering this question prior to getting access to the book. I did a quick literature search on potassium sorbate and like you said, it appears that it is used to stop fermentation in products such as homemade wine. I could not find any information specifically related to honey bees or bumble bees. This is important because one would need to know that potassium sorbate is not toxic to honey bees. However, I did find several papers in which researchers report the results from their investigations in which they tested the ability of potassium sorbate to control chalkbrood (spoiler alert: it did not control it). Nevertheless, Nelson may be right. I really appreciate the lead. I will add this to my list of things to test as I am curious if this will keep syrup from fermenting and otherwise be innocuous to bees.
Q How far do SHB larvae crawl?
How far will small hive beetle larvae travel from a hive to pupate? For example, say a hive is on concrete 12 × 12 ft (~3.7 m). Will they drop from the hive and travel 12 feet to dirt?
Stan Gore
May
A
Yes. They absolutely can travel more than 12 feet to reach ground in which to pupate. I always tell a story to illustrate this point. I conducted my Ph.D. work at Rhodes University in South Africa. My supervisor’s laboratory was on the second floor of the building. I used one of the rooms in that laboratory to rear small hive beetles. One morning, I got to work early, and noticed beetle larvae in the hall, outside my supervisor’s laboratory. I followed the beetle larvae to see where they were going. Some were crawling through the hall, down the steps, through the next floor, and to the front door of the building. I estimate that this was 30+ yards (27+ m) in one night. I get this question quite a bit when I give lectures on small hive beetles and I always tell this story to illustrate the point that the larvae can crawl a long distance to find soil. I do not think your 12×12-foot concrete slab will be large enough to limit beetle larvae access to soil. Colleagues of mine and I calculated the speed wandering larvae crawl and multiplied that, conservatively, by the number of days the larvae have been observed to crawl. Ultimately, we derived estimates of up to 1 km as wandering distances. This has not been verified in the field, but it illustrates the point that larvae can crawl a considerable distance from hives to find soil in which to pupate.
Q Hive entrances
I have been working at learning to keep bees since ‘17 I think it was, here in the Finger Lakes of NY. I use Langstroth equipment. My mentor, who is fortunately also my next door neighbor, said you use the 3/8 inch (9.5 mm) opening for the bottom boards in winter, and the 3/4 inch (~19 mm) in summer — or screened bottom boards, which only allow 3/4 inch entrances. My mentor got me a good start in beekeeping and got out of it himself, leaving me all his equipment.
Subsequent influencers and heavy robbing pressure in ‘20, ‘21 and ‘22 had me using the 3/8 inch side only, all year long, with even further entrance restrictions. I like how clean the bottom boards are and that it seems to deter mice better. Now this past winter, 12 of my 13 colonies survived and thrived, and I am not keeping up with assembling and building the new equipment required to keep up with the expansion that I would like to happen.
An obvious solution is to dust off the ten screened bottom boards I never used and put them in service, for the time being, at least. But this brings me to my question: Why the 3/4 inch entrance? What have I missed out on these years by not using it before? I do build all my boxes with a 13/16 inch (20.6 mm) disc entrance for additional ventilation, and some colonies do use those rather heavily on busy days (just mentioning that for a possible factor in the equation.)
The new bottom boards from Dadant that I assembled last week were all reversible, and came with entrance reducers for the 3/4 inch, so I take it that the 3/4 inch side has a reason, but I have yet to see it explained.
Jered Lepp
New York, May
A
Honestly, I do not think it matters that much which size you use. I tend to leave my entrances fully open (3/4 inch) around the year. If robbing happens, I will add the wooden entrance reducers that are available for sale from the equipment supply companies. I do this to restrict the entrance and make it easier for the bees to guard. If I lived in a colder climate, I would likely reduce the entrance during winter to keep out the cold drafts of air.
It is worth noting that honey bee colonies, left to their own devices, choose nest cavities that have entrances in the 1-2 inch (~2.5 to ~5 cm) range. Consequently, the standard Langstroth entrance is…
