Several red-winged grasshoppers (akabane-batta in Japanese), categorized as likely to become extinct in Japan, have been spotted in a grassland area in Nagano Prefecture, where they had not been seen in five decades, prefectural officials said.

The red-winged grasshopper is described in the Environment Ministry's red list of endangered species as critically endangered, and had not been seen anywhere in Japan since a sighting in 1986 in Niigata Prefecture.

Nagano Prefecture classified the species as extinct in its own red list in 2004.