I was recently sent this intriguing question from a reader:
Dear Dr. Dolittle,
I heard in my science class that because honeybees have such high blood sugar levels, they can survive freezing...is that true?
To answer this question, I turned to expert Dr. John G. Duman from the Department of Biological Sciences at the University of Notre Dame who studies antifreeze proteins in insects. Here is what he had to say:
In short, no.
Insects generally survive subzero environmental temperatures by evolving one of two strategies. Some are freeze tolerant, meaning that they can survive the freezing of their body fluids. In contrast, those species that die if frozen must evolve seasonal adaptations that prevent freezing of their body fluids in winter, such as various antifreezes that make them freeze avoiding. (For a recent review of this topic see the book Low Temperature Biology of Insects, edited by D. L. Denlinger and R. E. Lee, Cambridge University Press, 2010). However, honeybees are neither freeze tolerant nor freeze avoiding. They die of hypothermia if their body temperatures are lowered to approximately 7 degrees C. In fact, they are endotherms. Like humans and other mammals, they control their body temperatures by producing internal heat, mainly by shivering their flight muscles. In addition, they huddle together into a large mass that conserves the heat produced by the individual bees. Individuals within the cluster move in and out between the center and the outside edge of the cluster. This combination of endothermy and clustering keeps their body temperatures well above freezing right through the winter. In one experiment, when the air temperature around the cluster was kept at 5 degrees C, bees at the center of the cluster had body temperatures of 35 degrees C and temperatures of individuals on the outside edge were approximately 19 degrees C. The center of the cluster generally stays between 30 and 35 degrees C even at outside temperatures as low as -30 degrees C.
A number of insects, especially bees, wasps, and certain large moths are endothermic during the warm months, using the heat produced as a by-product of the flight muscles to maintain their thoracic temperatures. However, very few species remain endothermic through the winter. One serious problem for maintaining endothermy at low temperatures is that it becomes very energetically costly, requiring large amounts of food. However honeybees are able to remain endothermic because the honey that they have stored generally provides a sufficient energy source to get them through the winter.
If you have a question for Dr. Dolittle, please send it to drdlttl01@gmail.com.
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I am a high school science teacher, and I really appreciate this answer. I had never thought about it but now I am prepared for interesting discussions about endothermic bees and sugar as an energy supply- Thanks!
Yes, bees hate getting cold. Once they are cold, unless they are in their box, they will surely die, because they can't warm up again.
I agree "bees hate getting cold. Once they are cold, unless they are in their box, they will surely die, because they can't warm up again"
We found a large wasps nest on the house overhang and was able to take it down in one piece. My wife wants to take it to school for her science class. i have put the whole nest in our chest freezer hoping this kill the wasps in it. Will this do the trick?? thank you Edward Randall
Apparently that will do the trick! See here: http://www.beeswaspshornets.com/does-freezing-a-bee-or-wasp-nest-kill-i…
Large wasp in my garden in freezing temp for days ( nights) today I brought him indoors. He then started to move his wings and legs. Amazed!
HOW LONG COULD YOU FREEZE A LIVE WASP SO THAT YOU COULD RETURN IT TO BEING FULLY ACTIVE AGAIN..
..I BELIEVE THAT IT IS SOME CONSIDERABLE TIME
Alright jay, no need to shout...
Anyway, Do you have a reference for what you have written about them dying of hypothermia?
All the best
Question re bees: My understanding is that bees are in danger of not surviving temperature below 5 degrees C. What about the eggs? What temperature can they withstand?
I live in an area that can get down as low as -25°F in the winter and I have just started a new bee hive this spring. Should i take added protection to the hive in the winter time like cover it up or?
Chuck: absolutely the bees need protection at temperatures below 5 degrees C. I'm no expert as you can tell from "Q" #10, but for what it's worth, keep a small# of hives in a heated 8x10 storage shed. Keep temperature between 2 @ 5 degrees C. Lower & they could freeze, higher & they'll be more active than you'd like. If she'd not available, wrap with some seriously insulated covering & moderate temperature.
Anybody got an answer to my "Q # 10?
We had a 46 degree high temperature yesterday so I noticed many bees came out of the hive - not a lot, but some. I noticed after the temperature dropped, they all were back inside. There were a few dead ones remaining on the lid, or area in front of the entrance. After a night of freezing temps, I went out this AM, & brought in one of the dead bees. We like to examine them when we see them to look for mites. There were no mites, but my husbsnd was away at the time & I thought he'd like looking at it too, so I payed it on a napkin. An hour &1/2 later he retutnrd, & low & behold, the bee was moving around on the napkin.