Biogeography and evolution of Amazonian triatomines (Heteroptera: Reduviidae): implications for Chagas disease surveillance in humid forest ecoregions

An ecological-evolutionary classification of Amazonian triatomines is proposed based on a revision of their main contemporary biogeographical patterns. Truly Amazonian triatomines include the Rhodniini, the Cavernicolini, and perhaps Eratyrus and some Bolboderini. The tribe Rhodniini comprises two major lineages (pictipes and robustus). The former gave rise to trans-Andean (pallescens) and Amazonian (pictipes) species groups, while the latter diversified within Amazonia (robustus group) and radiated to neighbouring ecoregions (Orinoco, Cerrado-Caatinga-Chaco, and Atlantic Forest). Three widely distributed Panstrongylus species probably occupied Amazonia secondarily, while a few Triatoma species include Amazonian populations that occur only in the fringes of the region. T. maculata probably represents a vicariant subset isolated from its parental lineage in the Caatinga-Cerrado system when moist forests closed a dry trans-Amazonian corridor. These diverse Amazonian triatomines display different degrees of synanthropism, defining a behavioural gradient from household invasion by adult triatomines to the stable colonisation of artificial structures. Anthropogenic ecological disturbance (driven by deforestation) is probably crucial in the onset of the process, but the fact that only a small fraction of species effectively colonises artificial environments suggests a role for evolution at the end of the gradient. Domestic infestation foci are restricted to drier subregions within Amazonia; thus, populations adapted to extremely humid rainforest microclimates may have limited chances of successfully colonising the slightly drier artificial microenvironments. These observations suggest several research avenues, from the use of climate data to map risk areas to the assessment of the synanthropic potential of individual vector species.

Ecological niche modelling and differentiation between Rhodnius neglectus Lent, 1954 and Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae) in Brazil

Ecological niche modelling was used to predict the potential geographical distribution of Rhodnius nasutus Stål and Rhodnius neglectus Lent, in Brazil and to investigate the niche divergence between these morphologically similar triatomine species. The distribution of R. neglectus covered mainly the cerrado of Central Brazil, but the prediction maps also revealed its occurrence in transitional areas within the caatinga, Pantanal and Amazon biomes. The potential distribution of R. nasutus covered the Northeastern Region of Brazil in the semi-arid caatinga and the Maranhão babaçu forests. Clear ecological niche differences between these species were observed. R. nasutus occurred more in warmer and drier areas than R. neglectus. In the principal component analysis PC1 was correlated with altitude and temperature (mainly temperature in the coldest and driest months) and PC2 with vegetation index and precipitation. The prediction maps support potential areas of co-occurrence for these species in the Maranhão babaçu forests and in caatinga/cerrado transitional areas, mainly in state of Piaui. Entomologists engaged in Chagas disease vector surveillance should be aware that R. neglectus and R. nasutus can occur in the same localities of Northeastern Brazil. Thus, the identification of bugs in these areas should be improved by applying morphometrical and/or molecular methods.

Sistemática, filogenia e distribuição geográfica das espécies sul-americanas de Centris (Paracentris) Cameron, 1903 e de Centris (Penthemisia) Moure, 1950, incluindo uma análise filogenética do "grupo Centris" sensu Ayala, 1998 (Hymenoptera, Apoidea, Centridini)

Systematics, phylogeny and geographical distribution of the South American species of Centris (Paracentris) Cameron, 1903, and Centris (Penthemisia) Moure, 1950, including a phylogenetic analysis of the "Centris group" sensu Ayala, 1998 (Hymenoptera, Apoidea, Centridini). A cladistic analysis with the objective of testing the hypothesis of monophily of Centris (Paracentris) Cameron, 1903, and of studying its phylogenetic relationships with the other subgenera that belong to the Centris group, sensu Ayala, 1998, and the relationships among the species that occur in South America, is presented. Centris (Paracentris) is a group of New World bees of amphitropical distribution, especially diversified in the Andes and in the xeric areas of South and North America. Thirty-one species were included in the analysis, four considered as outgroup, and 49 characters, all from external morphology and genitalia of adult specimens. Parsimony analyses with equal weights for the characters and successive weighting were performed with the programs NONA and PAUP, and analyses of implied weighting with the program PeeWee. The strict consensus among the trees obtained in all the analyses indicates that C. (Paracentris), as previously recognized, is a paraphyletic group. In order to eliminate that condition, the subgenera C. (Acritocentris), C. (Exallocentris) and C. (Xerocentris), all described by SNELLING (1974) are synonymized under C. (Paracentris). The subgenus C. (Penthemisia) Moure, 1950, previously considered a synonym of C. (Paracentris), is reinstated, but in a more restricted sense than originally proposed and with the following species: Centris brethesi Schrottky, 1902; C. buchholzi Herbst, 1918; C. chilensis (Spinola, 1851), C. mixta mixta Friese, 1904, and C. mixta tamarugalis Toro & Chiappa, 1989. Centris mixta, previously recognized as the only South American species of the subgenus C. (Xerocentris), a group supposedly amphitropical, came out as the sister-species of C. buchholzi. The following South American species were recognized under Centris (Paracentris): Centris burgdorfi Friese, 1901; C. caelebs Friese, 1900; C. cordillerana Roig-Alsina, 2000; C. euphenax Cockerell, 1913; C. flavohirta Friese, 1900; C. garleppi (Schrottky, 1913); C. klugii Friese, 1900; C. lyngbyei Jensen-Haarup, 1908; C. mourei Roig-Alsina, 2000; C. neffi Moure, 2000; C. nigerrima (Spinola, 1851); C. toroi sp. nov.; C. tricolor Friese, 1900; C. unifasciata (Schrottky, 1913), and C. vogeli Roig-Alsina, 2000. The relationships among the subgenera of the "Centris group" were: (Xanthemisia (Penthemisia (Centris s. str. - Paracentris))). Centris xanthomelaena Moure & Castro 2001, an endemic species of the Caatinga and previously considered a C. (Paracentris), came out as the sister group of C. (Centris) s. str. A new species of C. (Paracentris) from Chile is described: Centris toroi sp. nov. Lectotypus designations and redescriptions are presented for Centris burgdorfi, C. caelebs, C. lyngbyei, C. tricolor, C. autrani Vachal, 1904 and C. smithii Friese, 1900. New synonyms proposed: C. buchholzi Herbst, 1918 = Centris wilmattae Cockerell, 1926 syn. nov.; C. caelebs Friese, 1900 = Paracentris fulvohirta Cameron, 1903. The female of C. vogeli Roig-Alsina, 2000 and the male of C. xanthomelaena are described.

As abelhas eussociais (Hymenoptera, Apidae) visitantes florais em um ecossistema de dunas continentais no médio Rio São Francisco, Bahia, Brasil

Highly eusocial bees (Hymenoptera, Apidae) flower visitors in a continental sand dune ecosystem from the medium São Francisco River, Bahia, Brazil. A community of highly eusocial bees in sand dunes, covered with caatinga vegetation, in the medium São Francisco River, Bahia (10º47' 37"S and 42º49' 25"W) was studied. The local climate is semi arid and hot, with mean temperature of 25.7 ºC and annual precipitation of 653.8 mm. Censuses took place every two months, from February to December of 2000. The bees were sampled on flowers with entomological nets, from 6:00 a.m. to 5:00 p.m. A total of 2,147 individuals of eight species of Apinae were found, of which Apis mellifera Linnaeus (40.2%), Trigona spinipes (Fabricius) (28.7%) and Frieseomelitta silvestri languida Moure (14.7%) were the predominant species. The diversity was H' = 1.53 and the evenness E' = 0.73. The bees were active during the whole year, but there was a significant variation in the monthly abundance of individuals (c2= 799.55; df= 35; p<0.0001). The daily activity was greater between 6:00 a.m. and 8:00 a.m. The low bee diversity observed is a consequence of the low richness of botanical species and of the small amount of sites for the bees' nests. The community of highly eusocial bees from the dunes presents organization patterns similar to those observed in other caatinga areas, albeit with some particularities.

A new species of Calloconophora Dietrich (Hemiptera, Membracidae) from the semi-arid region of northeastern Brazil

A new species of treehopper, Calloconophora gaudencia sp. nov., from Araruna, Paraíba State, is described and illustrated.

Duas novas espécies de Enchenopa Amyot & Serville (Hemiptera, Membracidae) do semi-árido do Estado da Paraíba, Brasil

Enchenopa eunicea sp. nov. e Enchenopa minuta sp. nov. (ambas de São José dos Cordeiros, Paraíba, Brasil ) são descritas e ilustradas.

Descrição da fêmea de Paracentronodus nevesi Barreira & Sakakibara (Hemiptera, Membracidae)

Um exemplar fêmea de Paracentronodus nevesi Barreira & Sakakibara, 2001, de São José dos Cordeiros, região de semi-árido (Caatinga), do Estado da Paraíba, é descrito e ilustrado. Até o presente, apenas o macho era conhecido.

Polinização de Vochysia lucida C. Presl (Vochysiaceae) em uma área de restinga na Bahia

As espécies de Vochysia são neotropicais e apresentam flores que podem ser visitadas por abelhas, beija-flores e borboletas. Este estudo teve como objetivo a análise das interações entre as flores de Vochysia lucida e seus visitantes florais, em uma área de restinga no Estado da Bahia, Brasil. V. lucida é uma espécie arbórea e apresenta inflorescências do tipo racemo, com cerca de 100 a 170 flores. As flores são zigomorfas, amarelas e foram consideradas melitófilas. O néctar floral é produzido e estocado em esporão, localizado no cálice. O pico de floração de V. lucida ocorreu em novembro e dezembro. Durante o estudo as flores abriam às 6:00 h, quando o estigma já estava receptivo. Na abertura da flor a antera já não estava mais presente e os grãos de pólen estavam depositados na parede do estilete, ocorrendo apresentação secundária de pólen. As pétalas caíam no final da tarde, por volta das 17:00 h. Os beija-flores embora freqüentes nas flores de V. lucida foram considerados visitantes oportunistas. Entre os visitantes florais registrados, as abelhas de grande porte foram consideradas os polinizadores mais eficientes, especialmente Xylocopa frontalis, por ter morfologia e comportamento adequados para contatar as estruturas reprodutivas da flor, durante as coletas de néctar, e por sua elevada freqüência de visita.

Comunidade de abelhas (Hymenoptera, Apoidea) e plantas em uma área do Agreste pernambucano, Brasil

O Agreste é uma região de transição entre floresta tropical úmida e caatinga no nordeste brasileiro. Nessa região, grande parte da vegetação nativa foi desmatada para a implantação de pastagens. Não é sabido se áreas degradadas mantém uma apifauna e flora melitófila diversificada, ou quais são associações entre abelhas e plantas que ocorrem nessas áreas. A cobertura vegetal atual é composta por pastos, vegetação ruderal e restos da vegetação nativa. Abelhas e plantas por elas visitadas foram coletadas mensalmente entre agosto de 2001 e julho de 2002, durante dois dias consecutivos entre 5h30 e 17h30. Foram coletados 1.004 indivíduos de abelhas pertencentes a 79 espécies. Apidae foi a família mais abundante e com maior riqueza de espécies (732 indivíduos e 43 espécies), seguida por Halictidae (194 indivíduos e 20 spp.), Megachilidae (47 indivíduos e 13 spp.), Colletidae (16 indivíduos e 2 spp.) e Andrenidae (15 indivíduos e 1 sp.). Foram registradas apenas três espécies de abelhas eussocais e cinco de Euglossini, dois grupos altamente diversificados nas florestas neotropicais. A ausência de abelhas sem ferrão nativas dos gêneros Plebeia, Frieseomelitta, Partamona, Scaptotrigona e Trigonisca, assim como de outras espécies de Euglossini, deve estar relacionada à falta de sítios de nidificação e à escassez de fontes de pólen e néctar nessa área degradada. Foram registradas 87 espécies de plantas melitófilas, a maioria ervas e arbustos. Árvores nativas isoladas, assim como plantas ornamentais e frutíferas cultivadas contribuem para manter parte da diversidade da comunidade de abelhas nativas.

The fauna of phlebotomines (Diptera, Psychodidae) in different phytogeographic regions of the state of Maranhão, Brazil

Phlebotomine specimens were captured in domiciliary and forest environments in 47 municipalities between 1982 and 2005 with the aid of CDC light traps. A total of 91 species were found, of which four belonged to genus Brumptomyia and 87 to genus Lutzomyia, distributed among the following subgenera: Evandromyia (6), Lutzomyia (5), Micropygomyia (2), Nyssomyia (9), Pintomyia (2), Pressatia (3), Psathyromyia (6), Psychodopygus (14), Sciopemyia (4), Trichophoromyia (2), Viannamyia (2); species groups: Aragaoi (2), Baityi (1), Dreisbachi (1), Migonei (12), Oswaldoi (8), Pilosa (1), Saulensis (2), Verrucarum (4) and ungrouped (1). Species diversity was greatest in areas where there was dense evergreen seasonal forest (52 species), ombrophilous forest (31) and meridional cerrados (23) and lowest in areas with mixed forest (forest with babassu palms, cerrado and caatinga). The greatest similarity index was observed for restinga and open evergreen seasonal forest (J=0.48). Dense evergreen seasonal forest had greatest similarity with ombrophilous forest (J=0.38). The phlebotomine fauna was species rich and unevenly distributed in Maranhão, reflecting the phytogeographical complexity of the state, which is a result of the great variety of ecosystems and climate zones.

Two new species of Lopesia Rübsaamen (Diptera, Cecidomyiidae) associated with Mimosa hostilis (Mimosaceae) in Brazil

Two new species of Lopesia Rübsaamen (Diptera, Cecidomyiidae) associated with Mimosa hostilis (Mimosaceae) in Brazil Two new species of Lopesia Rübsaamen (Diptera, Cecidomyiidae, Lopesiini), L. mimosae Maia, sp. nov. and L. pernambucensis Maia, sp. nov., that induce galls on Mimosa hostilis Benth. (Mimosaceae) are described and illustrated based on material from "caatinga" in Pernambuco, Brazil.

Uma nova espécie de Orthoderella Giglio-Tos (Mantodea, Mantidae, Photinainae) do Brasil

A new species of Orthoderella Giglio-Tos (Mantodea, Mantidae, Photinainae) from Brazil. The Neotropical genus Orthoderella Giglio-Tos includes four species recorded in Argentina, Bolivia, Uruguay, and from central western, southern, and southeastern Brazil. Orthoderella caatingaensis sp. nov., from the Caatinga biome in northeastern Brazil, is described here. This new species can be recognized by having a black spot on the inner face of the fore coxae, which extends to its posterior external face; phalloid apophysis of the left dorsal phallomere trapezoidal in shape with the right margin sinuous and a laminate anterior process; and a ventral phallomere with a sclerotized and rugous distal process. An identification key, in both Portuguese and English, to the five species of Orthoderella is presented.

Ant species (Hymenoptera, Formicidae) from the seasonally dry tropical forest of northeastern Brazil: a compilation from field surveys in Bahia and literature records

Ant species (Hymenoptera, Formicidae) from the seasonally dry tropical forest of northeastern Brazil: a compilation from field surveys in Bahia and literature records. The Caatingas occur predominantly in northeastern Brazil and comparatively it is the biome that received less attention than any other ecosystem in Brazil, representing the region where invertebrate groups are less known. We present here the first list of ant species of the Caatingas, compiling information from the literature, from a study of samples preserved in alcohol in the Laboratory of Entomology (Universidade Estadual de Feira de Santana), and from a field survey conducted in Milagres, Bahia, submitting standardized 1-m² samples of the leaf-litter to Winkler extractors. Summing all information, 11 subfamilies, 61 genera and 173 species (plus one subspecies) of ants are recognized in the biome. This species number does not consider morphospecies that could not be named due to the lack of reliable recent taxonomic information for some Neotropical ant genera. The list presented here for ant species of the Caatingas is therefore underestimated, but it is relevant because it allows the identification of areas to be sampled in order to improve our knowledge of the diversity of ants in this biome.

Fixação do N2 em leucena (Leucaena leucocephala) em solo da região semi-árida brasileira submetido à salinização

Com a finalidade de avaliar a tolerância de rhizobium loti em Leucaena leucocephala cv K8, submetida a níveis crescentes de salinidade, realizou-se um experimento em casa de vegetação, usando-se um Podzólico Vermelho-Amarelo textura franco-arenosa, coletado em Serra Talhada (PE). O experimento obedeceu ao arranjo fatorial 5 x 4, no delineamento em blocos ao acaso, com 3 repetições. Foram usados 5 níveis de salinidade do solo (C.E. = 1,5; 6,6; 10,1; 12,8 e 14,4 dS m-1) e 2 tratamentos inoculados (NFB 494 e SEMIA 6069), fertilização nitrogenada com 200 mg kg-1 de N (NH4NO3), e o controle sem inoculação e sem adubação nitrogenada. O incremento dos níveis crescentes de salinidade reduziu a nodulação (número e massa de nódulos), o rendimento de matéria seca e a acumulação de N na parte aérea. O tratamento com fertilização nitrogenada inibiu totalmente a nodulação em leucena, em todos os níveis de salinidade; contudo, promoveu melhores rendimentos na acumulação de N e na produção de matéria seca. Observou-se resposta significativa das plantas inoculadas com a estirpe SEMIA 6069, em todas as características avaliadas, superando os resultados obtidos com o isolado NFB 494.

Influence of tree species on the herbaceous understory and soil chemical characteristics in a silvopastoral system in semi-arid northeastern Brazil

Studies from some semi-arid regions of the world have shown the beneficial effect of trees in silvopastoral systems, by promoting the formation of resource islands and increasing the sustainability of the system. No data are available in this respect for tree species of common occurrence in semi-arid Northeastern Brazil. In the present study, conducted in the summer of 1996, three tree species (Zyziphus joazeiro, Spondias tuberosa and Prosopis juliflora: ) found within Cenchrus ciliaris pastures were selected to evaluate differences on herbaceous understory and soil chemical characteristics between samples taken under the tree canopy and in open grass areas. Transects extending from the tree trunk to open grass areas were established, and soil (0-15 cm) and herbaceous understory (standing live biomass in 1 m² plots) samples were taken at 0, 25, 50, 100, 150 and 200% of the average canopy radius (average radius was 6.6 ± 0.5, 4.5 ± 0.5, and 5.3 ± 0.8 m for Z. joazeiro, P. juliflora, and S. tuberosa , respectively). Higher levels of soil C, N, P, Ca, Mg, K, and Na were found under the canopies of Z. joazeiro and P. juliflora: trees, as compared to open grass areas. Only soil Mg organic P were higher under the canopies of S. tuberosa trees, as compared to open grass areas. Herbaceous understory biomass was significantly lower under the canopy of S. tuberosa and P. juliflora trees (107 and 96 g m-2, respectively) relatively to open grass areas (145 and 194 g m-2). No herbaceous biomass differences were found between Z. joazeiro canopies and open grass areas (107 and 87 g m-2, respectively). Among the three tree species studied, Z. joazeiro was the one that presented the greatest potential for use in a silvopastoral system at the study site, since it had a larger nutrient stock in the soil without negatively affecting herbaceous understory biomass, relatively to open grass areas.