Diet of the South American frog Leptodactylus ocellatus (Anura, Leptodactylidae) in Uruguay

The diet of Leptodactylus ocellatus (L., 1758) was studied in specimens collected at Maldonado Department (Uruguay), where monthly surveys were made between August 1998 and March 2000. A total of 143 frogs were collected, measured, sexed, and dissected, to assess stomach contents. The anurans were grouped into three age classes and four categories (considering sex and capture date). The trophic amplitude for each age class and sex-season category was quantified using Shannon-Weaver Index, and the trophic niche overlap between ages and categories by using the Pianka Index. Comparisons among treatments were made by G-tests. The most important prey items were coleopterans (IRI = 2547), and significant correlations were found between predator and prey sizes. The major differences on diet composition were found between extreme age classes (froglets and adults). Significant differences were also detected between sexes in the cold season but not in the warm season. Any of these changes in diet may be related with the availability of prey.

Three new andean species of Drosophila (Diptera, Drosophilidae) of the mesophragmatica group

Three new species of mesophragmatica group, Drosophila amaguana, Drosophila shyri and Drosophila ruminahuii from Pasochoa Forest Reserve, northern Ecuadorian Andes, are described. The two subgroups currently composing the mesophragmatica group are renamed as the mesophragmatica subgroup to which the first two species have been added, and the viracochi subgroup to which the latter species has been added. These subgroups are defined based on the direction of the basal scutellar setae, which are divergent in the species of the former subgroup and convergent in the latter.

First record of Chaunus achavali (Anura, Bufonidae) from Rio Grande do Sul, Brazil, with a key for the identification of the species in the Chaunus marinus group

The bufonid toad Chaunus achavali, a recently described species known only from Uruguay, is recorded for Brazil. This species is morphologically similar to C. ictericus and C. arenarum, and several individuals were labeled in Brazilian scientific collections under these taxa. A lectotype of C. arenarum is designated. Additional field notes on C. achavali and a key for the identification of the species in the Chaunus marinus group are presented.

Two new species of Drosophila belonging to the canalinea group (Diptera, rosophilidae)

Drosophila piratininga sp. nov. and Drosophila sampa sp. nov., belonging to the canalinea group of the subgenus Drosophila, are described based mostly on wild-caught specimens collected at a forest reserve of the Cidade Universitária "Armando de Salles Oliveira", an urban remnant of the montane Atlantic Forest located at west São Paulo city, state of São Paulo, Brazil. The two species are readily distinguished from each other mostly by having different wing patterns: the main crossveins being remarkably clouded in the first one and unclouded in the latter. Illustrations of terminalia are also provided.

Revalidation of Acanthagrion cuyabae (Odonata, Coenagrionidae) and description of the female, with a key to the Brazilian species of the viridescens group

Acanthagrion cuyabae Calvert, 1909 was described based on a male from State of Mato Grosso, Brazil. The female of this species was described based on morphological characters of four individuals collected in copula from State of Mato Grosso do Sul, and three other specimens of same locality. Acanthagrion cuyabae is here revalidated based on morphological characters of the female. Illustrated keys to the groups of Acanthagrion Selys, 1876 and species of the viridescens group occurring in Brazil are provided.

Another color morph of Sporophila Seedeater from the capuchinos group (Aves, Emberizidae)

The genus Sporophila (Cabanis, 1844) unites about 30 species of small seedeaters that predominantly inhabit open or semi-open areas in the Neotropical region. The taxonomy of this group is based on morphological studies from collected male specimens. The dynamic spatial and temporal variation in the male plumage and lack of knowledge of their vocalizations make it difficult to properly diagnose some species even today, so these two aspects account for the existing taxonomic dilemmas involving Sporophila. During a four-year field study, we investigated the natural history of a breeding population of Sporophila melanogaster (Pelzeln, 1870). This is an endemic species in Brazil, which reproduces in the high-altitude grasslands of the Atlantic Forest biome. We found four male specimens with clearly diagnosable plumage, distinct from the typical form of the species. Here we describe this previously unreported plumage form. Based on the evaluation of habitat use, vocalization, and reproductive behavior, we tested two hypotheses regarding its taxonomic status. We concluded that this is another case of an intra-specific color morph within the seedeaters of the "capuchinos" group.

Two new Neotropical species of Drosophila peruensis species group (Diptera, Drosophilidae)

The Drosophila peruensis species group was recently proposed and includes four taxa: D. atalaia Vilela & Sene, 1982, D. boraceia Vilela & Val, 2004, D. pauliceia Ratcov & Vilela, 2007, and D. peruensis Wheeler, 1959. All these species have most of setae or setulae of mesonotum arinsing from dark spots, wings with crossveins darker (except in D. atalaia) and hypandrium squared-shaped mostly fused to gonopods. Here, we describe two new species, Drosophila itacorubi sp. nov. and Drosophila paraitacorubi sp. nov., belonging to this species group. The male genitalia of these species are figured. An identification key to the D. peruensis species group is provided.

Neodrassex, a new genus of the Leptodrassex group (Araneae, Gnaphosidae) from South America

The new genus Neodrassex is proposed to include two new species of Gnaphosidae from Brazil. Neodrassex aureus sp. nov. is described from Amazonas, Paraná and Rio Grande do Sul states, and N. iguatemi sp. nov. is described from Paraná state. Neodrassex gen. nov. is characterized by small size, pale coloration, large anterior median eyes surrounded by black pigmentation, absence of a dorsal abdominal scutum in males and by the cheliceral dentition with 2-3 teeth on the promargin and 2-4 on the retromargin. The new genus is tentatively placed at the Leptodrassex group.

Formas de cultura de Trypanosoma rotatorium Mayer, 1843: isolado da rã Leptodactylus ocellatus do Brasil

Os autores estudaram o comportamento "in vitro" do Trypanosoma encontrado nas rãs brasileiras, visando critérios adicionais na caracterização específica deste grupo. Utilizaram diferentes meios de cultura (NNN, Novy e Mac Neal, SNB 9 de Diamond 1954, Boné & Steinert, 1956 Boné & Parent 1963 e Halevy & Gisry 1964) no isolamento do Trypanosoma rotatorium encontrado com certa freqüência na rã Leptodactylus com larga distribuição na região Neotropical. Observamso que o comportamento do T. rotatorium das rãs desta região em meios de cultura mostra características bem diferentes daquelas observadas com tripanosomas de outras regiões, quer seja pela dificuldade de manutenção em subcultura, quer pelas formas de divisão desenvolvidas. Empregamos os mesmos meios de cultura utilizados nos isolamentos dos tripanosomas de rã da Europa e como pode ser visto no Quadro I os resultados obtidos com material da região Neotropical são concordantes, surgerindo, pelo menos uma variação dentro da espécie.

Consideracões sobre a natureza, desenvolvimento e transmissão de Cytamoeba bacterifera Labbé, 1894 de Leptodactylus ocellatus

Com o objetivo de fornecer dados para o esclarecimento do controvertido problema da natureza de Cytamoeba bacterifera freqüentemente encontrada nos eritrócitos de Leptodactylus ocellatus, realizamos alguns testes citoquímicos. Demonstramos a presença do ácido ribonucleico e polissacarídeos não digeríveis pela ptialina em sua estrutura. Com o método de Feulgen, teste de referência para a caracterização do ácido desoxirribonucleico, obtivemos principlemnte resultados negativos; porém, um parasito com fraca e difusa positividade e algumas reações duvidosas também foram encontrados. Ao emrpegarmos o Verde Metila-Pironina, mesmo após o tratamento pela ribonuclease, e o Azul de Toluidina, também depois da ação desta enzima, não conseguimos confimar a presença de ADN. Como os elementos constituintes de C. bacterifera são minúsculos e, às vezes, não evidenciáveis, é possível que seu teor de ADN, porventura existente, seja muito pequeno e, conseqüentemente, de difícil demonstração por métodos cujos resultados são observados sob microscopia ótica, além de poder ficar facilmente encoberto por outras substâncias. Não estamos propensos a admitir uma provável natureza virótica para Cytamoeba baseados, principalmente, em alguns de seus aspectos estruturais (figs. 8, 15, 17 e 18) e na ausência de alteração no núcleo das células parasitadas. Apesar de não termos comprovado a presença de ADN, achamos possível que C. bacterifera seja um aglomerado intracitoplasmático de organismos modificados, cujas dimensões situam-se nas proximidades do limite de resolução do microscópio ótico, relacionados com as bactérias, assim como são, por exemplo, os Clamídios e as Riquétsias. Observamos o desenvolvimento de Cytamoeba em rã mantida em cativeiro por três meses e semanalmente examinada; constatamos decréscimo paulatino da parasitemia inicial e também que os seus tipos estruturais e medidas não estavam relacionadas com a etapa da infecção. Não conseguimos transmitir, por inoculação intra-peritoneal, Cytamoeba de L. ocellatus para Bufo crucifer.

Simulium argentiscutum sp. nov. (Diptera: simuliidae), a member of the S. amazonicum-group of species; description of adults, pupa and larva

The adult, pupal and larval morphology of S. argentiscutum sp. nov., a member of the S. amazonicum-group, is compared with S. amazonicum Goeldi and its distribution, biology and medical importance are discussed. S. argentiscutum is one the most important anthropophilic species in the S. amazonicum-group as it is responsible, together with S. amazonicum, for the transmission of Mansonella ozzardi in Brazil.

The microps group of Lutzomyia França with descriptions of two new species from South America (Diptera: Psychodidae: Phlebotominae)

Six species of phlebotomine sand flies in the genus Lutzomyia França from South America are included in the newly-created species group microps. References and illustrations of the species are given, including descriptions of two new forms - L. nematoducta n.sp., male and female from northern Brazil, and l. preclara n.sp. male from Colombia and Peru. The males in the species group microps are keyed.

New Phlebotomine Sandflies of the walkeri group (Diptera: Psychodidae) from Pará State, Brazil, with a pictorial key 1

The male and female of Lutzomyia carmelinoi n.sp., and the female only of L. baculus and L. williamsi, (Diptera:Psychodidae) are described and illustrated from specimens collected in Pará state, Brazil. A pictorial key is presented to these and the other members of the walkeri group.

A new Culicoides of the stigmalis group (Diptera: Ceratopogonidae)

Notes are presented on the three known Neotropical species of the Culicoides stigmalis group of boodsucking midges: alvarezi Ortiz, fluviatilis (Lutz), stigmalis Wirth, and on deanei n.sp., which is described from the state of Rio de Janeiro, Brazil. A diagnosis is given for the group, as well as a key for identification and comparative phtographs of the female wings.