Wasps over winter: Why hibernate?

This post is not about why wasps themselves would hibernate over winter. The reasons are fairly obvious: It's cold, and there's not enough food around to survive. (Incidentally, it's only the new queen wasps that hibernate, after they have mated with the ephemeral males - who are only alive for a matter of days, their only job being to mate and then die)

No, this post is about why a person would want to actively 'hibernate' a wasp over winter. Or, even, thousands of wasps.

To explain this, I've uploaded some pictures that explain the process of hibernating a wasp. And then, a couple of paragraphs on the presumed effects that this has on the ecosystem, particularly in the context of a community with a penchant for wasp larvae. Combined, I hope that this gives a good answer to the question 'Why hibernate?' - In short, what comes around goes around, and if you want wasps next year, well, you'd better hibernate a few this year.

The pictures below explain the hibernation process. (Written explanations pop up when you move the mouse over each picture)

A 'hebo house', purpose-built for keeping wasps. The house offers protection from the heat in summer and from the cold in winter. Along the tops of the shelves, pipes made of plastic and bamboo have been placed. When the new queen wasps start to look for a place to hibernate, they head for these pipes.

During the last days of November and the first days of December (exact dates vary depending on the weather conditions each year), the pipes are checked every morning for hibernating wasps. When found, they are tapped out into a tupperware.

Then, each wasp is lifted one by one from the tupperware and placed into a purpose-built hibernation box.

This box contains dry leaves and a cabbage leaf to mimic the forest floor, where the wasps would normally spend the winter.

These boxes are kept in a place where the temperature is constant throughout the winter months, protected from predators.

Next spring, the new queens will be released into different areas of the forest - usually areas where nests have been found in previous years.

So, why go to all this trouble? Because in an area where people scour the landscape for wasp nests in both the spring and autumn seasons, and then harvest these nests before the mating season, there's quite a high possibility that this will lead to a depletion in the wasp population the following year.

Therefore, by keeping a few nests aside, ensuring that the conditions are conducive to mating and hibernation, and then keeping the hibernating queens in protected conditions throughout the winter months, one ensures that there will be queen wasps who survive until the spring. 

In this way, the wasp population (and therefore the forest ecosystem as a whole: As insect predators and flower pollinators, wasps are an essential part of the ecosystem) is maintained, year after year - and people are still able to enjoy the annual harvest of hachi-no-ko!