Vol. 105, No. 2, March & April, 1994 1 1 1 KARYOTYPIC DATA ON THIRTEEN SPECIES OF NEARCTIC CARABID BEETLES (COLEOPTERA) 1 J. Galian, A.S. Ortiz, J. Serrano^ ABSTRACT: Mitotic and meiotic chromosomes of thirteen Nearctic species of cara-bid beetles have been studied. The male haploid chromosome number varies between n=ll+X and n=21+X. The results obtained allow the following conclusions: (1) The 2n=37 karyotype has been found in eight species, one of them belongs to the Limbata Stylifera group, thus corroborating its widespread occurrence among the main lineages of the fam-ily. (2) Data on Amara (Celia) moerens, 2n=37, fit the hypothesis about the ancestrality of this number for the genus Amara. (3) The trend towards low-numbered karyotypes observed in the tribe Lebiini has much progressed in Cymindis chevrolati, 2n=24. The chromosome number is already known for more than 750 spe-cies of the family Carabidae. Most cytogenetic studies on the Nearctic fauna have been concerned with the genus Bernbidion (160 species: Maddison, 1985; Smith, 1953). The chromosome number of other groups of Carabidae from this region were described in 50 species and compiled in Smith and Virkki (1978) and Serrano and Yadav (1984). New results on Nearctic species have been added by Galian et al. (1990a, 1992). The aim of this work is to increase the basic knowledge of the cytotaxonomy of North American carabids, by adding the results obtained in 13 Canadian and Mexican species, and discussing briefly their cytotaxo-nomic significance. MATERIALS AND METHODS The species analyzed were collected in the localities listed in Table 1. Results were obtained from one to four male adults per species. Identi-fications were made by G.E. Ball and D. Shpeley (Edmonton, Canada) and P. Moret (Paris, France). The beetles are deposited in the Departa-mento de Biologia Animal, Universidad de Murcia (Spain). Specimens of the three unnamed species of Platynus are also deposited in the U.S.N.M., Smithsonian Institution, Washington, D.C. Karyological analyses were carried out on testes using a routine orcein-squashing method described elsewhere (Galian et al., 1990). Chromosomes were tentatively arranged in pairs by size and shape (karyogram) in order to show gross features such as symmetry of the karyotype, occurrence of heteromorphic chromosomes, etc. 1 Received June, 1993. Accepted October 3, 1993 2 Departamento de Biologi'a Animal, Facultad de Veterinaria, Universidad de Murcia, Apdo. 4021, Murcia 30071, Spain ENT. NEWS 105(2): 111-118. March & April, 1994
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