Libelloides ramburi (M’Lachlan, 1875) is a large insect of the order Neuroptera that inhabits good grasslands of Japan, and is a rapidly decreasing species in various places. It has been previously recorded from 12 points in Kanagawa Prefecture, but only a few records are known in recent years. Therefore, it has been regarded as an endangered species on the Kanagawa Prefecture Red List. Since confirming this species in 2017, the authors have intensively investigated distribution of this species in the prefecture. As a result, we we found the species at 20 localities, mainly in the former Fujino Town area of Midori Ward, Sagamihara City in the northern part of the prefecture. Even in a similar grassland environment, the species could not be found and its distribution was limited. The environment in which this species is distributed is grassland where artificially mowing has been continued. Such distribution environment is diverse, but its habitat stability is fragile. Although the number of localities has increased, it has become clear that the distribution is localized and threatened with extinction.
