Heterochromatin characterization and ribosomal gene location in two monotypic genera of bloodsucker bugs (Cimicidae, Heteroptera) with holokinetic chromosomes and achiasmatic male meiosis.

Members of the family Cimicidae (Heteroptera: Cimicomorpha) are temporary bloodsuckers on birds and bats as primary hosts and humans as secondary hosts. Acanthocrios furnarii (2n=12=10+XY, male) and Psitticimex uritui (2n=31=28+X1X2Y, male) are two monotypic genera of the subfamily Haematosiphoninae, which have achiasmatic male meiosis of collochore type. Here, we examined chromatin organization and constitution of cimicid holokinetic chromosomes by determining the amount, composition and distribution of constitutive heterochromatin, and number and location of nucleolus organizer regions (NORs) in both species. Results showed that these two bloodsucker bugs possess high heterochromatin content and have an achiasmatic male meiosis, in which three regions can be differentiated in each autosomal bivalent: (i) terminal heterochromatic regions in repulsion; (ii) a central region, where the homologous chromosomes are located parallel but without contact between them; and (iii) small areas within the central region, where collochores are detected. Acanthocrios furnarii presented a single NOR on an autosomal pair, whereas P. uritui presented two NORs, one on an autosomal pair and the other on a sex chromosome. All NORs were found to be associated with CMA3 bright bands, indicating that the whole rDNA repeating unit is rich in G+C base pairs. Based on the variations in the diploid autosomal number, the presence of simple and multiple sex chromosome systems, and the number and location of 18S rDNA loci in the two Cimicidae species studied, we might infer that rDNA clusters and genome are highly dynamic among the representatives of this family.

[Host plants of Cerambycidae (Coleoptera) from northwest and central Argentina]. / Plantas hospedadoras y biogeografía de Cerambycidae (Coleoptera) del noroeste y centro de la Argentina.

Seventy four species of Cerambycidae (Coleoptera) were reared from forty eight host plants found into Yungas, Chaco and Prepuna phytogeografical provinces. The host plants belong Anacardiaceae, Asclepiadaceae, Bignoniaceae, Cactaceae, Cucurbitaceae, Euphorbiaceae, Juglandaceae, Leguminosae sensu lato (Caesalpinaceae, Fabaceae, Mimosaceae), Loranthaceae, Rhamnaceae, Rutaceae, Salicaceae, Sapindaceae, Solanaceae, Ulmaceae and Vitaceae. Some species of Cerambycidae and their host plants show similar distribution patterns: from northeastern Brazil through Paraguay and reach the Argentina at both sides of the Chaco Provine: at the east, along the river systems through Buenos Aires, and the at the west into forests of the Yungas Province or into North Sierra Chaco, a probably relictual community. Others species are restricted to the South America area of Prosopis, that comprise the Chaco, Monte and Espinal biogeographical provinces, and live in host plants of chaquenian lineage mainly Leguminosae sensu lato and Ulmaceae.

[Host plants of Cerambycidae (Coleoptera) species in Espinal and Buenos Aires Province, Argentina]. / Plantas hospedadoras de Cerambycidae (Coleoptera) en el Espinal periestépico y en la provincia de Buenos Aires, Argentina.

The host plants of Cerambycidae (Coleoptera) in the Province of Espinal (Chaquenian Dominion) and the province of Buenos Aires are mainly exotics, cultivated or naturalized, the last ones growing spontaneously and forming little forests. Forty two species of Cerambycidae are reported using these plants and other native species as hosts. Hylotrupes bajulus, originally introduced and a serious pest of furniture, is reported for first time in spontaneous pine forests in Sierra de la Ventana, south of the province of Buenos Aires.

[Host plants of Cerambycidae (Coleoptera) in the northeast of Argentina]. / Plantas hospedadoras de Cerambycidae (Coleoptera) en el noreste de Argentina.

New host plants and localities are recorded for 84 species of Cerambycidae of Chaco Province (Chaquenian Dominion) and Paranaense Province (Amazonian Dominion) in northeastern Argentina and Brazil. Host plants belong to Anacardiaceae, Asclepiadaceae, Apocynaceae, Bignoniaceae, Bombacaceae, Cactaceae, Caesalpinaceae, Capparidaceae, Casuarinaceae, Fabaceae, Mimosaceae, Moraceae, Nyctaginaceae, Polygonaceae, Rhamnaceae, Rutaceae, Sapindaceae, Sapotaceae and Ulmaceae. First records for Argentina and host plants: Compsocerus barbicornis Serville 1834, Desmiphora lenkoi (Lane 1959), Neocompsa serrana (Martins 1962) and Trachysomus dromedarius (Voet 1778). First host plants records of rare or uncommon Argentine species of Cerambycidae are Methia tubuliventris Gounelle 1913, Paraleptidea femorata Gounelle 1913 and Oncideres pepotinga Martins 1981.