Population ecology of the red-winged grasshopper, Celes skalozubovi akitanus (Orthoptera, Acrididae), in Japan.

The significant loss of semi-natural grasslands in Japan has led to a decline in the populations of grassland specialist insects. We studied the population structure and basic ecology of a grassland specialist, the red-winged grasshopper Celes skalozubovi akitanus, a critically endangered species in Japan, to enable conservation management of grasshoppers and their habitats. A field survey using transect counts and a mark–release–recapture survey was conducted over two years (2016 and 2017). We found that C. s. akitanus fed on a variety of grassland plants in the study area but not on the dominant species Miscanthus sinensis and Pteridium aquilinum. The recapture rate of C. s. akitanus was considerably high (approximately 68% or more), and two isolated populations were found in the studied grassland. The estimated total population size was < 120–140 individuals, indicating that the study population was extremely small. Our results show that this species exhibits a strong sedentary behaviour because most of the adults move less than 5 m in a season and prefer bare ground within the grassland. The continued implementation of the annual prescribed burning and partial mowing of the habitat is necessary to conserve C. s. akitanus. In addition, creating continuity between two populations is effective for the survival of populations in this study area. [ABSTRACT FROM AUTHOR]