NEW AND LITTLE-KNOWN TAXA OF RHYTIDOCHROTINAE (ACRIDIDAE, ORTHOPTERA)FROM COSTA-RICA

Three new monospecific genera are described from montane areas of Cost a Rica. Like the other three known Costa Rican rhytidochrotine genera (Hylopedetes Rehn, 1929, Scirtopaon Descamps & Rowell, 1984 and Microp aon Descamps & Rowell, 1984) they belong to the atympanate and apterou s division of the subfamily. All are apparently confined to small geog raphical areas. Exerythracris is volcanica n.sp. is a fern eater from the light, gaps and edges of montane forest, and resembles in gross mo rphology the similarly specialised Hylopedetes. It is the most norther ly representative of the subfamily so far described, extending almost to the Costa Rican/Nicaraguan border. Brackeracris varablancensis n.sp . is found in successional areas (landslips, anthropogenically altered habitats) in montane forest; its diet is unknown, but does not appare ntly include ferns; morphologically it is closest to Scirtopaon. Talam ancacris palustris n.sp. is confined to a few relict subalpine swamps and appears to eat Asteraceae preferentially; it is not obviously clos ely allied to the other genera. Additionally, new morphological, ecolo gical and biogeographic data are given for the three previously descri bed genera.