Help: WASPS in the Bee Shed!

[Adie]

Freezing works a treat, three days @ -20 C killed everything when I tried it, but if you are worried just leave it for a week. Much better than using a pesticide and the kids found the nest fascinating - they even mounted the queen on a piece of cork. The fish also loved the larvae.

 

[Karol]

Karol

I assume you are aware of the weta that can repeatedly be frozen? According to Wikipedia (may or may not be correct) it has particular proteins in its haemolymph to prevent it freezing. It may be a reasonable assumption to make that a queen wasp is similar. As another points out it’s necessary for a queen to survive the winter (as is also true of a weta) so it’s worth her while making the proteins, indeed there is an evolutionary pressure making such a necessity. There is no such evolutionary advantage to a worker as it would be dead before season’s end in any event. The extra effort in making the “antifreeze” would be a selection pressure not to bother, in other words worker wasps not making the proteins have more resources for other wasp activities and would do better. As wasps have castes the biochemistry could well be different. My hypothesis based on little more than supposition would therefore be that worker wasps can be easily killed by freezing, queens cannot.
It would be interesting to see how low a temperature a queen bumble could cope with too.

If there's one thing I've come to respect about wasps more than anything else is that they are the consumate definition of biological efficiency which gives credence to your hypothesis. To some extent the construction of the nest is also testament to your hypothesis. Vespine wasps that reside in the northern hemisphere build enclosed insulated nests that they are able to regulate thermally to a greater or lesser extent. Polistes wasps which reside in warmer climates have open nests. It would not make much sense in building a thermally insulated nest if the workers could withstand freezing.

We did the research on the queens because it has direct relevance to what we do in IWM in being able to predict wasp prevalence from one season to the next. It's less of an issue for us in terms of worker wasps which is why our research didn't extend that far. That said there will be a short window during the summer when nests are full of new queens which may then survive freezing.