Occurrence of sibling species of Lutzomyia longipalpis (Diptera : Psychodidae) in Venezuela: First evidence from reproductively isolated sympatric populations

The delimitation of cryptic species within the main vector of the American visceral leishmaniasis, Lutzomyia longipalpis, remains a topic of controversy. An analysis of generic variability based on 8 enzymatic loci revealed fixed differences in 2 diagnostic loci, adenylate kinase (Ak) and hexokinase (Hk), between sympatric and allopatric populations at 4 localities in Venezuela. The absence of heterozygotes for these 2 loci within 1 locality indicates, for the first time, the presence of 2 sympatric reproductively isolated populations or cryptic species within L. longipalpis. Significant differences were also detected between these cryptic species in the allele frequencies of glucose-6-phosphate isomerase (Gpi) and malate dehydrogenase, decarboxylating (Me). One species showed mean heterozygosities that ranged between 6.6% and 6.7%, with 1.6-1.9 alleles detected per locus, while the other had mean heterozygosities that ranged from 4.3% to 6.3%, with 1.3-1.6 alleles per locus. Comparisons of isozyme profiles with published data suggests that 1 species is similar to the L. longipalpis described in Colombian and Brazilian populations, whereas the other has not been previously reported.

Comparison of the external morphology of Rhipicephalus sanguineus (Latreille, 1806) (Acari : Ixodidae) ticks from Brazil and Argentina

In the present study the external morphology of semi-engorged Rhipicephalus sanguineus females ticks from Brazil and Argentina were compared by scanning electron microscopy. Many differences were detected among the R. sanguineus collected at the two localities, such as body size, shape of the genital pore, and morphology of the sensory structures. All these characteristics are fundamental for the diagnosis of species of the genus Rhipicephalus and thus indicate the need for further comparisons and, the taxonomical revision of this species of tick in the Neotropics. (c) 2005 Elsevier B.V. All rights reserved.

Morphometric analysis of the venom gland in worker bees of Apis mellifera (Hymenoptera : Apidae) from the pantanal region of Mato Grosso do Sul

In Apis mellifera the acid or venom gland is composed of secretory cells that surround a channel that opens into a reservoir devoid of musculature. This gland can at times present apical branching. In this study we recorded the frequency of branched venom glands in workers of Africanized bees (Apis mellifera Linnaeus) from six localities in the Pantanal region of Mato Grosso do Sul, and analyzed the relation among the length of the main duct, the length of the duct from the reservoir to the beginning of branching, the length of the branched segment (when present) and the total length of the gland. We sought to determine the probable genotypes of the bees from each population by using the model proposed by Alves-Junior. The frequency of branched glands varied from 50% to 83% in the worker bees coming from those places, indicating that this characteristic is primitive in these bees. The results of the Analysis of Discriminant Functions indicated significant differences in the morphometrical segments of the venom gland (Wilk's Lambda = 0.065; F-(27,F-30) = 4.507; P < 0.001), and permitted a differentiation of the populations studied. The genotypes inferred for the bees of each locality agree with the results obtained in the Analysis of Discriminant Functions and form three distinct groups, with some overlapping areas among them. In all of the populations considered the phenotype largevenom gland was predominant. It is inferred that bees with this phenotype (venom gland larger than S. 15 mm) have Gm(1) Gm(1) genotype, being therefore homozygotes for the major alleles and also for the modifier genes that codify this morphological trait. The high frequency of worker bees with large venom gland in all the places considered makes viable the development of a selection program in order to obtain bees with longer venom glands, aimed at the commercial production of venom by the beekeepers of the Pantanal region of Mato Grosso do Sul.

Pericentric inversion events in karyotypic distinction of Brazilian lizards of genus Phyllopezus (Squamata, Gekkonidae) detected by chromosomal banding patterns

Cytogenetic investigations based on conventional and differential staining analysis (C-and replication R-banding and Ag-staining) were carried out on eight specimens of Phyllopezus periosus, 17 of P. pollicaris pollicaris, and one of P. pollicaris przewalskii collected from different localities of Brazil. P. periosus and P. p. pollicaris share the same diploid number of 2n = 40 chromosomes, and their karyotypes are very distinctive regarding to the number of biarmed and uniarmed chromosomes. After careful side-by-side comparison of R-banded chromosomes in both taxa, pronounced homology between, at least, eight pairs was revealed. The R-banding patterns allowed us to postulate that karyotype differentiation could be due to pericentric inversion events. P. p. przewalskii (2n = 38) exhibited a very similar karyotype to that found in P. p. pollicaris, except for the presence of one metacentric pair, which probably resulted from a Robertsonian rearrangement. Single and multiple pairs of NOR-bearing chromosomes, showing variation in number and location, were detected among the three forms of Phyllopezus. Similar C-banding patterns were found in P. periosus and P. p. pollicaris. Sex chromosomes were not positively identified.

Análise morfológica da glândula de veneno de Apis mellifera L. (Hymenoptera: Apidae) em populações de Mato Grosso do Sul

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chromosome evolution in three Brazilian Leptodactylus species (Anura, Leptodactylidae), with phylogenetic considerations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cryptic sexual populations account for genetic diversity and ecological success in a widely distributed, asexual fungus-growing ant

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Obtenção e uso das plantas medicinais no distrito de Martim Francisco, Município de Mogi-Mirim, SP, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Geographic patterns in fruit colour diversity: do leaves constrain the colour of fleshy fruits?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nucleolus organizer regions in Physalaemus cuvieri (Anura, Leptodactylidae), with evidence of a unique case of Ag-NOR variability

We studied ten specimens of Physalaemus cuvieri collected at different localities in Brazil using conventional staining and banding techniques. All specimens had 2n = 22. There were karyotypic variants: distinct patterns in the number and chromosome localization of Ag-NORs as well as in the corresponding secondary constrictions. Preliminary C-banding patterns obtained for specimens From two localities are also suggestive of karyotypic differentiation in P. cuvieri.

Ocorrência e conservação de Touit melanonotus (Aves, Psittacidae) no sul do Brasil

O apuim-de-costas-pretas [Touit melanonotus (Wied, 1820)] é uma espécie florestal endêmica da Mata Atlântica Brasileira e de relevante interesse conservacionista. Trata-se de uma ave com poucas informações disponíveis acerca de sua história natural e distribuição geográfica e novas observações são importantes fontes de informação para auxiliar na conservação da espécie. Aqui reavaliamos o primeiro registro da espécie e apresentamos novas observações no estado do Paraná, sul do Brasil. As vocalizações atribuídas a T. melanonotus e que consubstanciaram sua ocorrência no estado foram examinadas com auxílio de espectrogramas e identificadas como vozes de Pionopsitta pileata (Scopoli, 1769). Não obstante, T. melanonotus ocorre com certa regularidade no Paraná, como indicado por novos registros da espécie em sete localidades distribuídas por todo o litoral do estado. Esta ave foi registrada principalmente em florestas de terras baixas e, uma vez que esta fisionomia sofre intensas pressões antrópicas, sugerimos que esforços de conservação da espécie devem priorizar a preservação desses hábitats.

Feeding of Oligosarcus hepsetus (Cuvier, 1829) (Characiformes) in the Serra do Mar State Park - Santa Virgínia Unit, São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Taxocenose de anuros de uma mata semidecídua do interior do Estado de São Paulo e comparações com outras taxocenoses do estado, sudeste do Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new species of the Dendropsophus parviceps group from the western Amazon Basin (Amphibia: Anura: Hylidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular phylogeny and karyotype differentiation in Paratelmatobius and Scythrophrys (Anura, Leptodactylidae)

Paratelmatobius and Scythrophrys are leptodactylid frogs endemic to the Brazilian Atlantic forest and their close phylogenetic relationship was recently inferred in an analysis that included Paratelmatobius sp. and S. sawayae. To investigate the interspecific relationships among Paratelmatobius and Scythrophrys species, we analyzed a mitochondrial region (approximately 2.4 kb) that included the ribosomal genes 12S and 16S and the tRNAval in representatives of all known localities of these genera and in 54 other species. Maximum parsimony inferences were done using PAUP* and support for the clades was evaluated by bootstrapping. A cytogenetic analysis using Giemsa staining, C-banding and silver staining was also done for those populations of Paratelmatobius not included in previous cytogenetic studies of this genus in order to assess their karyotype differentiation. Our results suggested Paratelmatobius and Scythrophrys formed a clade strongly supported by bootstrapping, which corroborated their very close phylogenetic relationship. Among the Paratelmatobius species, two clades were identified and corroborated the groups P. mantiqueira and P. cardosoi previously proposed based on morphological characters. The karyotypes of Paratelmatobius sp. 2 and Paratelmatobius sp. 3 described here had diploid chromosome number 2n = 24 and showed many similarities with karyotypes of other Paratelmatobius representatives. The cytogenetic data and the phylogenetic analysis allowed the proposal/corroboration of several hypotheses for the karyotype differentiation within Paratelmatobius and Scythrophrys. Namely the telocentric pair No. 4 represented a synapomorphy of P. cardosoi and Paratelmatobius sp. 2, while chromosome pair No. 5 with interstitial C-bands could be interpreted as a synapomorphy of the P. cardosoi group. The NOR-bearing chromosome No. 10 in the karyotype of P. poecilogaster was considered homeologous to chromosome No. 10 in the karyotype of Scythrophrys sp., chromosome No. 9 in the karyotype of Paratelmatobius sp. 1, chromosome No. 8 in the karyotypes of Paratelmatobius sp. 2 and of Paratelmatobius sp. 3, and chromosome No. 7 in the karyotype of P. cardosoi. A hypothesis for the evolutionary divergence of these NOR-bearing chromosomes, which probably involved events like gain in heteochromatin, was proposed.