Winter is always a difficult phase for almost all animals. To survive cold and food shortages and to ensure the preservation of the species, there are a variety of methods. In the case of wasps, the annual cycle is a particularly astonishing cost-benefit phenomenon.
Workers die in winter
Immense mobilization of forces for species conservation
Wasps, especially the colony species, go to great lengths to secure their species from year to year. The cycle can be broken down into the following stages:
- Queen founds a nest
- Breeding masses of workers
- raising sex animals
- nuptial flight and mating
- Hibernation of young queens
Spring - founding of the state and setting up a workers' army
First, in the spring, a queen wasp establishes a new colony and lays eggs in the first brood chambers. Huge numbers of individuals have to be reared until the summer, devoting their entire lives to preparing for the autumn mating season. Thus, the wasps produce the spring over one generation of workers at a time.
Late summer - emergence of the sexual animals
From August onwards, the sex animals that are important for the actual reproduction are raised - i.e. drones and new young queens. During this time, the workers have to do so much maintenance work that they develop an enormous appetite themselves and, without considering the consequences, they happily tuck into anything sweet they can get - including our ice cream cones, as most of us may have experienced or Danish pastries at the garden table.
Autumn - peak and reproduction
In autumn, the so-called nuptial flight takes place - drones and young queens leave the nest to mate with other sexual animals outside in different countries. Once this is done, the entire team that has worked towards this most important step in the annual cycle goes into it. Before they die, the animals do the final work in the nest and clean it of weak or malformed larvae. Then they have finally fulfilled their target and are no longer needed.
winter
The only wasps that don't die by winter are the fertilized young queens. They are what all the preparatory work has been invested in. In order for a young queen to survive the cold period without food, she looks for a sheltered spot that is safe from major temperature fluctuations: for example, a niche under tree bark, a rotted tree stump or a compost heap. There she crawls and assumes a huddled posture: she crosses her wings under her body and puts her legs close to the side. Some paper wasps also overwinter in groups.
In order not to freeze to death, its body produces the sugar alcohol glycerol (which, by the way, is also used in antifreeze) and allows the wasp to withstand temperatures of down to -20°C. To prevent starvation, their organism shuts down to an economy mode: breathing and heartbeat slow down significantly, so that only a minimum of energy is used.
Despite these precautions, not all young queens make it through the winter. They can be attacked by mold or be preyed on by rodents or birds.