Comparative study of the stridulatory sulcus,buccula and rostrum of the nymphs of Triatoma guazu Lent & Wygodzinsky, 1979 and Triatoma jurbergi Carcavallo,Galvão & Lent, 1998 by scanning electron microscopy (Hemiptera,Reduviidae)

The ultrastructural morphology of the ventral region of the head (rostrum and buccula) and proesternum (stridulatory sulcus) of nymphs from the 1st to 5th instars of Triatoma guazu Lent & Wygodzinsky, 1979 and Triatoma jurbergi Carcavallo, Galv?o & Lent, 1998 was described. Morphological differences between the two species and of the five nymphal stages development of each species were observed. These structures showed systematic differential characteristics of the studied species and may be used to increase their taxonomic range.     

Adult and nymphs of Microtriatoma trinidadensis (Lent, 1951) (Hemiptera: Reduviidae) caught from peridomestic environment in Bolivia.

This is the first report of adult and nymphs (20 nymphs of all stages and 4 adults) of Microtriatoma trinidadensis (Lent 1951) (Hemiptera: Reduviidae: Triatominae) collected in peridomestic environment, in the department of La Paz, Bolivia. These specimens were associated to Rhodnius stali Lent, Jurberg & Galv?o 1993. The exceptional finding of M. trinidadensis in peridomestic environment, illustrates the general tendency of triatominae to adapt to human dwellings and dependences.     

Morphological and histological study of eggs of six species of the Triatoma genus (Hemiptera: Reduviidae)

The objective of this study was to analyze the morphological and histological characteristics of eggs from six triatomine species in order to obtain a generic and specific characterization of this group of Trypanosoma cruzi vectors and better understand their phylogenetic and taxonomic aspects. The eggs of the respective species came from the collection of the Laboratório de Triatomíneos e Culicídeos da Faculdade de Saúde Pública/USP, from the Insetário do Servi?o Especial de Saúde de Araraquara - SESA and from the Triatomine insectary of the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos (FIOCRUZ), in Rio de Janeiro. Morphological studies were done with optical microscopy and scanning electron microscopy. Histological analyses used only optical microscopy. All of the species analyzed showed a predominance of hexagonal cells. The exchorion of Triatoma breyeri Del Ponte, T. costalimai Verano Galv?o, and T. tibiamaculata (Pinto) consists of unornamented cells, overlapping or slightly separated, with a smooth, padded appearance. Meanwhile, in T. matogrossensis Leite Barbosa, T. sherlocki Papa, Juberg, Carcavallo, Cerqueira Barata, and T. williami Galv?o, Souza Lima, the exchorion cells are ornamented on their entire surface with perforations and fissures. Egg histology showed undulations, pores, and orifices. The study helps to expand the generic and specific knowledge of the Triatominae subfamily. The characteristics identified in the exchorion of the eggshells can help separate close species. These new parameters will back the elaboration of future dichotomous keys, help to determine each vector species role and expand knowledge of the various species.     

Biology of Triatoma klugi Carcavallo,Jurberg, Lent & Galvão 2001 (Heteroptera: Reduviidae) under laboratory conditions: effects of distinct blood sources and susceptibility to Trypanosoma cruzi and Trypanosoma rangeli

The life cycle of Triatoma klugi Carcavallo, Jurberg, Lent & Galv?o 2001 was compared under laboratory conditions using two groups of the F1 generation obtained from field-collected bugs. Among the 100 nymphs weekly fed on mice (Group A) or chicken (Group B), 77% of Group A and 67% of Group B reached the adult stage, and the mean time from the first nymphal stage to adult was 190.08 +/- 28.31 days and 221.23 +/- 40.50, respectively. The average span in days for each stage per group and the number of blood meals required for each stage were also evaluated. The overall mortality rate was 23% and 33% for Groups A and B, respectively. The mean number of eggs laid per month in a three-month period was of 56.20, 51.70 and 73.20 for Group A, and 64.50, 53.50 and 38.71 for Group B. Despite the blood source, comparative analysis revealed no statistically significant differences in the life cycle of T. klugi under laboratory conditions. Infection rates over 60% were observed for both Trypanosoma cruzi strains tested. Even revealing high infection rates of the hemolymph by T. rangeli strains, T. klugi revealed no salivary gland infections and was not able to transmit the parasite.     

Rhodnius amazonicus Almeida, Santos & Sposina, 1973, bona species, close to R. pictipes Stål, 1872 (Heteroptera, Reduviidae, Triatominae)

The discovery of two atypical specimens of Rhodnius pictipes St?l, 1872 in French Guiana and the examination of the female holotype of R. amazonicus Almeida, Santos & Sposina, 1973, the only specimen of this species so far known, lead us to propose the rehabilitation of R. amazonicus synonymized with R. pictipes. The male is described for the first time and the female redescribed. Both external characters and genitalia distinguish R. amazonicus from R. pictipes. R. amazonicus shows affinities not only with pictipes but also with R. stali Lent, Jurberg & Galv?o, 1993 and R. paraensis Sherlock, Guitton & Miles, 1977. A key is provided for these four species forming, in all likelihood, a natural group, i.e. the "pictipes group".     

Insecticidal activity of cerrado plant extracts on Rhodnius milesi Carcavallo, Rocha, Galvão & Jurberg (Hemiptera: Reduviidae), under laboratory conditions

Chagas' disease is chiefly transmitted by feces of haematophagous bugs (Triatominae) that ingested Trypanosoma cruzi from blood of infected people or animals. Pyrethroids have been the main insecticides used against these insects. However, some populations of insects have shown significant levels of resistance to several pyrethroids, indicating the need of new insecticides for the control of triatomines. Insecticidal activity of 24 Cerrado plant extracts belonging to five species of four families were assayed on fourth instar nymphs of Rhodnius milesi Carcavallo, Rocha, Galv?o & Jurberg (Hemiptera: Reduviidae), under laboratory conditions. For the extract application on triatomines, 50 microg of the extract were topically applied in duplicate on dorsal tergites of ten insects. Insects topically treated with acetone, ethanol, as well as insects with no treatment were used as controls. Triatomines were observed over a 28-day period. Hexanic and ethanolic extracts of Simarouba versicolor, Guarea kunthiana, Guarea guidonia and Talauma ovata caused mortality between 20% and 95% of R. milesi in comparison with the controls, which showed no insect mortality. These preliminary data suggest that the ethanolic extract of the root bark of S. versicolor and the hexanic extract of the root of G. guidonia, responsible for a 95% and 75% insect mortality, respectively, should be chemically investigated and monitored through biological assays in order to determine their insecticidal components, that could be used as a molecular model or as biorational compounds for use in insect control programmes.     

Three new species of Peristicta Hagen in Selys (Odonata: Zygoptera: Protoneuridae) from Brazil

Three new species of Peristicta Hagen in Selys from Brazil are described and illustrated: P. janiceae from Minas Gerais State (Diamantina, Gouvêa, Lagoa Santa, Serra do Cara?a, Serra do Cipó, Urobotanga), P. jalmosi from Goiás State (Chapada dos Veadeiros, Reserva da Universidade de Brasília) and Minas Gerais State (Urobotanga, Lagoa Santa, Ponte Nova, S?o Jo?o del Rey,) and P. muzoni from Mato Grosso State (Serra da Bodoquena). An identification key for males of Peristicta is presented.     

Pterygodermatites (Paucipectines) jägerskiöldi (Nematoda: Rictulariidae) from Gracilinanus agilis and G. microtarsus (Marsupialia: Didelphidae) in Brazilian pantanal and Atlantic forest by light and scanning electron microscopy

Pterygodermatites (Paucipectines) j?gerski?ldi Lent and Freitas, 1935, a parasitic nematode of the small intestine of the marsupial Gracilinanus agilis (Mammalia: Didelphidae) from the Pantanal of Mato Grosso do Sul state, and G. microtarsus from Atlantic Forest of Rio de Janeiro state, Brazil, were analyzed by light and scanning electron microscopy. Details of the surface topography such as the oral aperture, cephalic papillae, 2 papillae in posterior end, and longitudinal cuticular elements represented by combs and spines are presented along with measurements, adding new taxonomic characters to the previous diagnostic feature of P. (P.) j?gerski?ldi based on light microscopy. In addition, two new hosts records and two new geographical distributions for this nematode are reported.     

A new species of the oliveirai complex (new designation for matogrossensis complex) from the State of Rio Grande do Sul, Brazil

The authors describe a new species of Triatominae (Hemiptera, Reduviidae) from the State of Rio Grande do Sul, Brazil. The study was made with specimens captured in basaltic formations, at an average altitude of 750 m.o.s.l. The new species is included in the oliveirai complex together with other four species T. williami, T. matogrossensis, T. guazu and T. jurbergi). The new species was compared with the most similar one, T. oliveirai, from which the main differences are on the proportions of head, ante and postocular regions, the general color pattern and the male genitalia, specially on the median process of the pygophore, the support of phallosome, the vesica and the process of the endosome.     

Seasonality and relative abundance of Tabanidae (Diptera) captured on horses in the Pantanal, Brazil.

Once a month, from June 1992 to May 1993, collections of tabanids on horse were conducted in the Nhecolandia, Pantanal State of Mato Grosso do Sul, Brazil. Tabanid catches using hand nets were conducted from sunrise to sunset at grassland and cerrad?o (dense savanna) habitats. A total of 3,442 tabanids from 21 species,12 genera, and 3 subfamilies were collected. Although species abundance varied seasonally depending on habitat, no habitat specificity was observed for the most abundant species. In the grassland, 1,625 (47.2%) tabanids belonging to 19 species were collected, while 1,817 (52.8%) tabanids from 17 species were caught in the cerrad?o. The number of tabanid species varied from 7 during winter (July/August) to 15 in the spring (October). Tabanus importunus (56%) was the most abundant species, followed by T. occidentalis (8.2%), and T. claripennis (8.1%). The tabanid peak, in October, coincided with the beginning of the rainy season. The population peak of most species, including those with higher vector potential, suggests that the rainy season can be considered as the period of potentially higher risk of mechanical transmission of pathogens by tabanids to horses in the region.     

Nyssomyia intermedia (Lutz & Neiva, 1912) and Nyssomyia neivai (Pinto, 1926) (Diptera: Psychodidae: Phlebotominae) geographical distribution and epidemiological importance

Nyssomyia intermedia (Lutz & Neiva 1912) and N. neivai (Pinto 1926) are possible vectors of tegumentary leishmaniasis in some regions of Brazil. Further, the latter was until recently, considered a junior synonym of the former. This study has the purpose of updating our knowledge of the geographical distribution of these species, based on specimens deposited at the collection of the Centro de Pesquisas René Rachou-Fiocruz, Faculdade de Saúde Pública-Universidade de S?o Paulo, and on data presented by literature as also to associate this distribution with the cutaneous leishmaniasis cases reported. It has been reported that N. intermedia occurs in the states of the Northeastern Region, in Rio de Janeiro, Espírito Santo, on the northern coast of S?o Paulo, in eastern Minas Gerais, Mato Grosso do Sul, and Goiás, close to the border with Minas Gerais and Bahia. N. neivai occurs in the Southern Region, southern coast and in western S?o Paulo, southern and western Minas Gerais, southern Goiás, and southern Pará, beyond Argentina, Bolivia, and Paraguay. It is important to highlight that N. intermedia and N. neivai occur in sympatry in Minas Gerais and S?o Paulo. N. intermedia or N. neivai are predominant or are captured abundantly in several cutaneous leishmaniasis foci in the Southeastern and Southern regions of Brazil.     

Pelecitus helicinus Railliet & Henry, 1910 (Filarioidea,Dirofilariinae) and other nematode parasites of Brazilian birds

We report Pelecitus helicinus Railliet & Henry, 1910 from 13 species of birds of 2 orders and 7 families, collected from the states of S?o Paulo and Mato Grosso, Brazil. All 13 constitute new host records for this nematode. In addition, we report the first record of Aprocta golvani Diaz-Ungria, 1963 from Brazil and Monasa nigrifrons (Bucconidae), as well as a number of other nematode records from Neotropical birds.     

Tabanidae (Diptera) of Amazônia XX. description of Tabanus pseudonebulosus n.sp

Tabanus pseudonebulosus, new species, is described based on 217 female specimens and 5 males collected in Venezuela (Guarico, Aguaio, Santa Elena, and Palmarito) and in Brazil (Parcí: Santana do Araguaia, Serra das Andorinhas in S?o Geraldo do Araguaia, Serra Norte Carajás and Gorotire; Amazonas: Canutama; Mato Grosso do Sul: Corumbá), mostly in open vegetation, scrub forest and in rocky environments. Observed intraspecific variation in the specimens is presented and related to collection localities, and morphological differences are diagnosed in relation to the similar species Tabanus nebulosus DeGeer 1776 and T. importunus Wiedemann 1828. Morphometrical data and indices for specimens in different localities are provided. Drawings and photo of the new species are presented.     

Autosomal and sex chromosomal polymorphisms with multiple rearrangements and a new karyotype in the genus Rhipidomys (Sigmodontinae, Rodentia)

Two diploid numbers and five karyomorphs were found in ten specimens of Rhipidomys (Sigmodontinae, Rodentia) from three states in Brazil: 2n = 50 from Amazonas, and 2n = 44 from Mato Grosso and Bahia. CBG, GTG, and RBG-banding and Ag-NOR analyses were performed, as well as fluorescence in situ: hybridization with (T2AG3)7 probes. The new diploid number of 2n = 50 was associated with two different fundamental numbers (FN = 71 and 72) as a result of pericentric inversions and addition/deletion of constitutive heterochromatin. The samples from two localities (Aripuan? and Vila Rica) in the state of Mato Grosso shared 2n = 44 and FN = 52, but their karyotypes differed because of pericentric inversions. Although the single specimen from Bahia had the same diploid number as the samples from Mato Grosso, its karyotype and FN were completely distinctive. Karyological comparison of GTG-banding patterns revealed total homology between the karyotypes of the specimens from Bahia and Mato Grosso, implying the occurrence of 14 autosomal pericentric inversions. Homologies between ten of the autosomes in the karyotypes with 2n = 50 (FN = 72) and 2n = 44 (from Vila Rica, MT) were demonstrated. The differentiation between 2n = 44 and 2n = 50 involved five pericentric inversions, addition/deletion of constitutive heterochromatin in both autosomes and sex chromosomes, at least one Robertsonian rearrangement and other not detected rearrangements. Despite the remarkable number of rearrangements, interstitial telomeric sites (ITS) were not detected. Sex chromosomes also exhibited polymorphism in size and morphology.     

Genotype by environment interaction in Nelore cattle from five Brazilian states

Records from 75,941 Nelore cattle were used to determine the importance of genotype by environment interaction (GEI) in five Brazilian states. (Co)variance components were estimated by single-trait analysis (with yearling weight, W450, considered to be the same trait in all states) and multiple-trait analysis (with the record from each state considered to be a different trait). The direct heritability estimates for yearling weight were 0.51, 0.39, 0.44, 0.37 and 0.41 in the states of Goiás, Mato Grosso, São Paulo, Mato Grosso do Sul and Minas Gerais, respectively. The across-state genetic correlation estimates between Goiás and Mato Grosso, Goiás and Minas Gerais, São Paulo and Minas Gerais, and Mato Grosso do Sul and Minas Gerais ranged from 0.67 to 0.75. These estimates indicate that GEIs are biologically important. No interactions were observed between Goiás and São Paulo, Goiás and Mato Grosso do Sul, Mato Grosso and São Paulo, Mato Grosso and Mato Grosso do Sul, Mato Grosso and Minas Gerais, or São Paulo and Mato Grosso do Sul (0.82 to 0.97). Comparison of single and multiple-trait analyses showed that selection based on the former was less efficient in the presence of GEI, with substantial losses (up to 10%) during selection.     

Prevalence and level of antibodies to the circumsporozoite protein of human malaria parasites in five states of the Amazon region of Brazil

The aim of this study was to determine the prevalence of malaria infection and antibodies against the repetitive epitopes of the circumsporozoite (CS) proteins of Plasmodium falciparum, P. malariae, P. vivax VK210, P. vivax VK247, and P. vivax-like in individuals living in the states of Rond?nia, Pará, Mato Grosso, Amazonas, and Acre. Active malaria transmission was occurring in all studied sites, except in Acre. P. falciparum was the predominant species in Pará and Rond?nia and P. vivax in Mato Grosso. Infection by P. malariae was low but this Plasmodium species was detected in Rond?nia (3.5%), Mato Grosso (2.5%), and Pará (0.8%). High prevalence and levels of serological reactivity against the CS repeat peptides of P. falciparum were detected in Rond?nia (93%) and Pará (85%). Sera containing antibodies against the CS repeat of P. malariae occurred more frequently in Rond?nia (79%), Pará (76%), and Amazonas (68%). Antibodies against the repeat epitope of the standard CS protein of P. vivax VK210, P. vivax VK247, and P. vivax-like were more frequent in Rond?nia, Pará, and Mato Grosso. The high frequency of reactions to P. malariae in most of the areas suggests that the infection by this Plasmodium species has been underestimated in Brazil.     

Polymorphism of the ITS-2 region of the ribosomal DNA of the Triatominae Rhodnius domesticus, R. pictipes, R. prolixus and R. stali

Abstract The polymerase chain reaction?restriction fragment length polymorphism technique (PCR?RFLP) was used to compare Rhodnius domesticus (Neiva & Pinto), R. pictipes (Stal), R. prolixus (Stal) and R. stali (Lent, Jurberg & Galvão) (Hemiptera: Reduviidae). The enzyme BstUI differentiated R. domesticus, R. pictipes and R. prolixus, and HhaI differentiated R. domesticus, R. pictipes and R. stali. With the fingerprinting analysis generated by these two enzymes, it was possible to clearly identify all four species in the study.     

Campylocentrum benellii and C. paludosum spp. nov. (Angraecinae–Orchidaceae): two new leafless species from Brazil

The leafless condition is present in two neotropical epiphyte genera of Orchidaceae, Campylocentrum and Dendrophylax. Only the first one is reported from Brazil, where seven leafless species are recorded, and four of them are endemic. This study describes two new species of Campylocentrum from the Atlantic forest of São Paulo state and Amazon forest of Acre, Mato Grosso and Rondônia states. It also provides a key to the Brazilian species of leafless Campylocentrum, illustrations, and a discussion of the affinities of the new species with allied ones.     

A new species of Triatominae from Tamil Nadu, India

Abstract A new species of the genus Linshcosteus Distant, 1904 (Hemiptera: Reduviidae: Triatominae) is described from specimens collected near Kalakkadu, Tamil Nadu state, southern India. Specimens were found in deep crevices between rocks, in a region of semi‐arid scrub jungle. The distinctiveness of the new species was demonstrated by a morphometric analysis including the five previously described species of Linshcosteus, all from India. Nine measurements of the head were used in an isometric size‐free principal component analysis. In terms of discrete morphology the new species, Linshcosteus karupus sp.n. Galvão, Patterson, Rocha & Jurberg differs from the most similar one, L. kali Lent & Wygodzinsky, 1979 , by its very prominent anterolateral projections of the pronotum, by the length to width ratio of the pronotum, by the pilosity of the head and several other characters, including phallic structures. A revised key is presented for the six species of the genus.