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The karyotype of the grasshopper Spathalium helios Rehn 1918. (Orthoptera, Acridoidea, Ommexechidae)

A. Mesa; C.S. Fontanetti; H. Costa

Instituto de Biociências, UNESP, Campus de Rio Claro, Av. 24-A s/no., 13500 Rio Claro, SP, Brasil

ABSTRACT

The karyotype of the species Spathalium helios is described and compared with that of closely related S. audouini. The similarity between the chromosomal sex-determining mechanism of the two, suggests a common origin by means of a single X-autosome fusion.
The difference in the centromere position of the Y chromosome reinforces arguments in favor of specific status in S. helios, previously questioned because of a great morphological variability in S. audouini.

Keywords: Karyotype; Spathalium helios; Orthoptera.

REFERENCES

Mesa, A. (1963). Acerca de la cariologia de Ommexechidae (Orthoptera, Acridoidea). Rev. Soc. Urug. Ent. 5: 37-43.

Mesa, A. and Ferreira, A. (1977). Cytological studies in the family Ommexechidae (Orthoptera, Ommexechidae). Acrida 6: 261-271.

Ronderos, R. (1972). Notas para una revisión dela sub-familia "Ommexechinae" II. El género Spathalium Bolivar. Rev. Mus. La Plata (N.S.) 11: 175-208.

Rehn, J.A.G. (1918). On Dermaptera and Orthoptera from South Eastern Brazil. Trans. Amer. Ent. Soc. 44: 181-222.