Autosomal polyploidy and male meiotic pattern in the bug family Nabidae (Heteroptera)

Karyotypes of 18 species of Nabidae (Heteroptera), belonging to the genera, Nabis (11), Himacerus (3), Hoplistoscelis (1), and Pagasa (1) were studied. The data on Nabis meridionalis Kerzhner 1963), N. tesquorum (Kerzhner 1968 ), N. ussuriensis (Kerzhner 1962), N, pallidus Fieber 1861, N. sareptanus D ohrn 1862, Hoplistoscelis sordidus (Reuter 1872), and Pagasa fusca (Stein 1 857) were obtained for the first time in this study. Karyotypes of Nabis pu nctatus A. Costa 1847, N. ferus (Linnaeus 1758), N. pseudoferus Remane 1949 , N. rugosus (Linnaeus 1758), N. stenoferus Hsiao 1964, N. limbatus Dahlbom 1851, N, reuteri Jakovlev 1876. N. flavomarginatus Scholtz 1847, Himacerus apterus (Fabricius 1798), H. mirmicoides (O. Costa 1834, and H. maracandic us (Reuter 1890) were re-examined. A karyotype of 2n = 18 (16 + XY), which seems to be the most characteristic of Nabidae as a whole, was found in 12 species. Nabis pallidus and N, sareptanus showed a precise numerical doubli ng of the autosomal complement compared with the modal karyotype, 2n = 34 ( 32 + XY). Autosomal polyploidy is discussed as a possible evolutionary mech anism for these species, Meiosis in males of the above species was studied in detail. Male meiosis in Nabidae was shown to follow a highly peculiar sc enario differing in many aspects from that known in the majority of the Het eroptera taxa.