The Insects of Kushiro
Over 1,000 species of insects inhabit the Kushiro Wetlands. Many insect eggs and larvae spend the winter in stasis before hatching and emerging in late April. The warmer months of April to November are the best times to see the insects in the area.
An ideal breeding environment
The water and vegetation of the marsh support many species of insects, supplying food sources and shelter. Some species, such as the subarctic darner dragonfly (Aeshna subarctica), lay their eggs on mosses and sedges at the edges of swamps and bog ponds, where the larvae can feed on aquatic insects. Others inhabit higher ground, like the green hairstreak butterfly (Neozephyrus japonicus). It lays its eggs under the leaf buds of alder trees (Alnus japonicus), which provide shelter and food.
The sounds of summer
Over the summer months, the sounds of various insect species can be heard around the Kushiro Wetlands. The yezoharuzemi cicada (Terpnosia nigricosta) starts to sing in late May, followed by the koezozemi cicada (Lyristes bihamatus) in late July. At the end of summer, the rasp of the long-horned grasshopper (Gampsocleis ussuriensis) fills the grasslands around the wetlands.
A life’s work
The insect specimens on display at the Kushiro City Museum are part of a much larger collection assembled by Ijima Kazuo (1928–2016), an expert on the insects of eastern Hokkaido. He collected and classified insects in the area for much of his life.