Karyotypes, male reproductive system, and abdominal trichobothria of the Berytidae (Heteroptera) with phylogenetic considerations

The karyotype of fourteen species of Berytidae has been investigated (ten of them in this paper). All studied Metacanthinae, except possibly Metatropis , have 2n(♂)= 14 + XY. In three examined genera of Berytinae the karyotypes are dissimilar: in Neides and Apoplymus (Berytinae) the chromosome number is 2n(♂)=14 + XY, as for Metacanthinae. In Berytinus spp. the chromosome number is very high ( B.distinguendus: 2n(♂)=30 + XY; B.clavipes: 2n(♂)=32 + XY: B.minor: 2n(♂)=40 + XY).
The structure of the male reproductive system of eleven species is studied. Apoplymus (Berytinae) has two elongate follicles per testis and two pairs of mesadenial glands (mg). Metacanthinae and Neides (Berytinae) have a single elongate follicle per testis and two pairs of mg. Berytinus spp. differ in a number of characters: follicles are shorter and wider, two in each testis; a paired and an unpaired mg.
The number and position of the abdominal trichobothria of twenty-nine species of Berytidae is discussed.
The ancestral condition of the three examined characters is found in primitive genera of both Berytinae and Metacanthinae. The genus Berytinus shows a derived condition in all of these characters.