PROC. ENTOMOL. SOC. WASH. 102(1). 2000, pp. 120-128 COMPARATIVE STUDY OF SPERMATHECAE IN ELEVEN RHAMMATOCERUS SAUSSURE 1861 GRASSHOPPER SPECIES (ORTHOPTERA: ACRIDIDAE: GOMPHOCERINAE: SCYLLININI) Cristiane Vieira de Assis-Pujol and Michel Lecoq (CVAP) Museu Nacional, UFRJ, Departamento de Entomologia, Quinta da Boa Vista, Sao Cristovao, 29.940-040, Rio de Janeiro, Brazil (e-mail: [email protected]); (ML) Cen-tre de cooperation intemationale en recherche agronomique pour le developpement, Prifas, BP 5035, 34032, Montpellier Cedex 1, France (e-mail: [email protected]) Abstract. — The spermathecae of 1 1 Rhammatocerus Saussure 1861 grasshopper species are described [R. brasiliensis (Bruner 1904), R. brunneh (Giglio-Tos 1895), R. cyanipes (Fabricius 1775), R. giierrai Assis-Pujol, 1997, R. palustris Carbonell 1988, R. pictiis (Bruner 1900), R. pratensis (Bruner 1904), R. pseudocyanipes Assis-Pujol 1997, R. schis-tocercoides (Rehn 1906), R. sujfusus (Rehn 1906) and R. viatorius viatoriiis (Saussure 1861)]. This taxonomic character, which has never been assessed in the tribe Scyllinini, is critical for determining grasshopper species. It also may be helpful in a taxonomic reclassification of species and provide a basis for reviewing the genus Rhammatocerus and the entire tribe Scyllinini. Key Words: Acrididae, Scyllinini, Rhammatocerus, spermatheca In most taxonomic analyses of acridians, the phallic complex is the main morpholog-ical character used to distinguish species (Dirsh 1956, 1961). However, this character sometimes proves impracticable, e.g., for diagnosing some Gomphocerinae genera (Carbonell 1995). In such cases, the female genitalia, especially the spermatheca, may provide a basis for determination. Slifer (1939) described this distinguishing feature for many acridian species, and to a lesser extent by Dirsh (1957) and other authors, but these studies are almost solely descrip-tive. Spermatheca design has never been used as a basis for a review of current tax-onomic groups. Nevertheless, as early as 1939, Slifer (1939) stated that the sperma-theca would be a relevant criterion for de-termining families and subfamilies. Uvarov (1966) point out that the distal part of the spermathecal duct is subject to considerable variations, characteristic for some taxonom-ic groups. Amedegnato (in litt.) noted that the spermatheca and diverticula are useful diagnostic characters and could even pro-vide a basis for a phylogenic reclassifica-tion. However, Dirsh (1957) regard the spermatheca as a subsidiary taxonomic character of the higher categories to be used with caution. In fact, very few studies have been carried out to assess the potential rel-evance of spermatheca design for differen-tiating species within an Acrididae genus. Grasshoppers of the genus Rhammato-cerus Saussure 1861 are distributed from southern USA to Argentina (Otte 1981). This group is characterized by high intra-specific variation and a relatively hetero-geneous external morphology. The econom-ic impact of these grasshoppers has in-creased markedly over the last 15 years in Brazil and other South American countries.