In Otsu City, which faces Lake Biwa, the largest in Japan, there starts a problem in November, because a lot of giant chironomids occur. Along the shores, it is hated by people such as at restaurants.

People call this “the Lake Biwa midge”. The scientific name is Propsilocerus akamusi .

About 20 years ago, I saw a full of buckets of this in front of convenience stores, but these days it’s not so many.

The larvae live on the bottom of the lake. Since it is an environmental indicator species of strong pollution, this may mean that the lake has been cleaned.

Recommended time: November

Recommended place for observation: Biwako-Hamaotsu Station etc. anywhere along the lake