Hornets and Their Nests
Hornets play an important role in controlling insect populations. There are several species of hornet in Kushiro, including one of the world’s largest, the Japanese giant hornet (Vespa mandarinia japonica). Among other species in the area are the Japanese yellow hornet (Vespa simillima simillima) and Asian yellowjackets (Vespula flaviceps).
Nest building
The wetlands are rich in nest materials such as decaying logs, tree bark, and dead grasses. Different species of hornet use different materials to build their nests, but the construction process is similar. After the queen emerges from hibernation, she builds several hexagonal cells from materials she has chewed into a pulp, then lays eggs. The eggs hatch into workers that collect materials to expand the nest, then build more cells. As the worker population grows, the nest expands gradually outwards, like a balloon. Unlike bees, hornets do not store honey inside their nests.