Meiotic karyotypes and structure of testes of nineteen species of jumping-lice (Hemiptera, Psylloidea) from South Africa

The karyotypes of 19 species of Psylloidea from South Africa belonging to subfamilies Paurocephalinae, Euphyllurinae, Diaphorininae, Euphalerinae, Acizziinae, Ciriacreminae (Psyllidae), Calophyinae (Calophyidae) and Triozinae (Triozidae) were studied for the first time. In 16 species the modal diploid number of chromosomes was found to be 2n=24+X, while 3 species have other chromosome numbers. In Colophorina sp. the chromosomal set consists of 2n=22+X while in Peripsyllopsis speciosa 2n=8+X; the latter being one of the lowest numbers of chromosomes described in psyllids so far. On the other hand, Pauropsylla tricheata is the first species characterized by a chromosomal number higher than the modal one, 2n=26+X. The male gonads of 18 species were described. In 15 of these each testes consisted of two follicles and spermatocystes were arranged in one row. This structure is typical for the majority of psyllid species. Polymorphism in the number of testicular follicles in Calophya shini (2-3 follicles) was revealed. In two species, Trioza carvalhoi and T. thibae, each testis consists of a single follicle with spermatocystes arranged in two rows

The secondary contact zone of phylogenetic lineages of the Philaenus spumarius (Hemiptera : Aphrophoridae) : an example of incomplete allopatric speciation

Previous studies on the phylogeography of the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae) suggest the existence of a contact zone of its main phylogenetic lineages along mountain chains in Europe and western Asia. This study presents a detailed examination of the population genetics of P. spumarius within the Carpathian Mountains. The main objective was to determine whether the populations inhabiting that area consist of individuals belonging to different genetic units and whether the observed pattern could be an example of secondary contact zone which formed after incomplete allopatric speciation. Specimens from six transects across the Carpathian arc were examined. The mitochondrial phylogeography of the meadow spittlebug in the examined area clearly shows that individuals from both main clades meet and mix there. Representatives of all three main EF1-alpha clades were also found. The present distribution of the main clades with a zone of overlap along the mountain ranges may suggest that these phylogenetic lineages form a young hybrid zone. Moreover, a limited number of individuals were shown to possess heteroplasmic mitochondrial DNA, which gives additional support to intraspecific hybridization. P. spumarius could be used in future work as an excellent model species in investigating population genetics, intraspecific hybridization, and speciation in progress

Mediterranean species of the spittlebug genus "Philaenus" : modes of chromosome evolution

The evolution of karyotypes and sex determination system of Philaenus Stål (Auchenorrhyncha: Aphrophoridae) species is studied here in detail. The most plausible scenario of chromosomal rearrangements accompanying phylogenetic differentiation in Philaenus is advanced. It is postulated that the ancestral karyotype of Philaenus was 2n = 24 + X0. Karyotype changes occurred several times independently in the genus. The karyotype of 2n = 22 + X0 (P. spumarius and P. tesselatus) originated from 2n = 24 + X0 by fusion between two autosomal pairs. The neo—XY system (P. arslani, P. loukasi, P. signatus, P. maghresignus, and P. tarifa) also originated from the 24 + X0 karyotype by means of independent fusions between autosomes and the original X chromosome. The neo—X(1)X(2)Y system (P. italosignus) evolved from the 2n = 22 + neo—XY karyotype by an additional fusion between the Y chromosome and one more autosomal pair. The neo—X(n)Y system of P. italosignus is the first reported case of an evolutionarily fixed multiple sex chromosome system in Auchenorrhyncha

A new species of the genus Rhaphidosoma Amyot et Serville, 1843 (Heteroptera, Reduviidae), with data on its chromosome complement

A new species, Rhaphidosoma paganicum sp. nov. (Heteroptera: Reduviidae: Harpactorinae: Rhaphidosomatini), is described from the Dry Zone of Myanmar. It is the fifth species of Rhaphidosoma Amyot et Serville, 1843, known from the Oriental Region, and the first record of the genus for Myanmar and Indochina. The structure of the external and internal terminalia of the male and female is described and illustrated in detail. The completely inflated endosoma is described for the first time in reduviids. The complex structure of the ductus seminis is shown; it terminates with a voluminous seminal chamber which opens with a wide secondary gonopore and may be a place where spermatophores are formed. The new species is compared with all congeners from the Oriental Region and Western Asia. It is characterised by the absence of distinct tubercles on the abdominal tergites of the male, the presence only two long tubercles and small rounded ones on the abdominal tergites VII and VI, respectively, in the female, the presence of short fore wing vestiges which are completely hidden under longer fore wing vestiges, and other characters. In addition to the morphological description, an account is given of the male karyotype and the structure of testes of Rh. paganicum sp. nov. and another species of Harpactorinae, Polididus armatissimus Stål, 1859 (tribe Harpactorini). It was found that Rh. paganicum sp. nov. has a karyotype comprising 12 pairs of autosomes and a multiple sex chromosome system (2n♂=24A+X1X2X3Y), whereas P. armatissimus has a karyotype comprising five pairs of autosomes and a simple sex chromosome system (2n♂=10A+XY). The males of these species were found to have seven and nine follicles per testis, respectively. FISH mapping of 18S ribosomal DNA (major rDNA) revealed hybridisation signals on two of the four sex chromosomes (Y and one of the Xs) in Rh. paganicum sp. nov. and on the largest pair of autosomes in P. armatissimus. The presence of the canonical “insect” (TTAGG)n telomeric repeat was detected in the chromosomes of both species. This is the first application of FISH in the tribe Raphidosomatini and in the genus Polididus Stål, 1858

Additional new data proving that early publications on the polymorphism of the spittlebug of the genus Philaenus were lacking in systematics

Abstract In this comprehensive paper the importance of species is emphasized. It is demonstrated that careful biosystematic studies on the two species of the genus Philaenus known until recently, increased the number of species up to eight so far. These discoveries appear to be fundamental in explaining the expression, role, and evolution of polymorphism in this genus

Karyotype characterization of planthopper species Hysteropterum albaceticum Dlabola, 1983 and Agalmatium bilobum (Fieber, 1877) (Homoptera: Auchenorrhyncha: Issidae) using AgNOR-, C- and DAPI/CMA3 -banding techniques

Males of Hysteropterum albaceticum Dlabola, 1983 and Agalmatium bilobum (Fieber, 1877) display a chromosomal complement of 2n = 26 + X, which is a basic one of the tribe Issini (Issidae). In the present study, silver staining, C-banding and a base specific CMA3 -and DAPI-banding were used with the aim of identifying possible cytogenetic markers and distinguishing between karyotypes with the same chromosome number and no detectable inter-species differences in karyotype structure. We characterized the species studied in terms of the distribution and molecular structure of C-heterochromatin regions and the location of nucleolus organizing regions (NORs). The species are shown to differ considerably in the amount of heterochromatin, its distribution pattern along the karyotypes and its stain ability with DAPI and CMA3