CHROMOSOMES IN 2 STILT BUG SPECIES METATROPIS-RUFESCENS HERRICH-SCHAEFFER SSP. LINNEAE WAGNER AND BERYTINUS MINOR HERRICH-SCHAEFFER (BERYTIDAE, HETEROPTERA)

The karyotypes of two stilt bug species Metatropis rufescens (Herrich- Schaeffer) ssp. linneae Wagner and Berytinus minor (Herrich-Schaeffer) (Heteroptera, Berytidae) were reinvestigated by an improved method to analyze chromosomes and their meiotic behaviour. The chromosome formu la 2n (male) = 18 + XY for M. rufescens ssp. linneae was confirmed and a novel chromosome formula for B. minor, 2n (male) 42 + X1X2X3Y, was given. This is the first finding of multiple sex chromosome system in this family. Male meiosis is chiasmatic for autosomes. Sex chromosomes undergo post-reductional meiosis. C-banding method revealed heterochr omatic bands near one of the telomeres in some but not in all chromoso mes in M. rufescens ssp. linneae. The present data on chromosomes in t he family Berytidae are discussed.