Genimar Rebouças Julião

Insetos galhadores associados a duas espécies de plantas invasoras de áreas urbanas e peri-urbanas

Insects have been considered as important bioindicators of environmental changes and habitat quality. In spite of its sessile habit, easy localization, abundance and host specificity, insects that induce galls have not been utilized in studies of this nature. It was investigated the suitability of gall-inducing insects associated to two ruderal host plant species (Baccharis dracunculifolia and Vernonia polyanthes: Asteraceae) as bioindicators of habitat quality. The following questions were addressed: (i) is gall-inducing insect diversity influenced by different types of land use?; (ii) are the responses of galling insect communities different between host plants?; (iii) how does the biotic and physical features of the biotope influence the gall-inducing insect diversity? It was found 6,226 galls, belonging to six galling insect species on V. polyanthes and 11 galling species on B. dracunculifolia. No difference was found in galling species richness among land use types. Nevertheless, gall-forming insect abundance was statistically different among the biotopes studied. Insect galls were more numerous in biotopes with lower urbanization levels. Gall abundance showed a strong and positive relationship with the percentage of vegetal cover. Gall-forming insect communities on both host species showed differential responses to the different land use types. The results suggest that three factors may be involved with galling insect diversity in urban areas: (i) habitat structure in the biotope; (ii) resource abundance (host plant abundance and distribution); and (iii) frequency and intensity of management in reserves, parks, city squares, wastelands found at a given urban area.

Anthropic effects on sand fly (Diptera: Psychodidae) abundance and diversity in an Amazonian rural settlement, Brazil

Sand flies (Diptera: Psychodidae) are responsible for the transmission of protozoan parasites that cause leishmaniases. They are found predominantly in forests, but some species exploit environments that have been subject to deforestation and subsequent human colonization. Studies conducted in Brazil over the past 30 years show that some species are adapting to peri-urban and urban settings. We evaluated sand fly diversity and abundance in the rural settlement of Rio Pardo, Presidente Figueiredo Municipality, Amazonas State, Brazil. Settlement households were divided into four categories. These categories were determined by the human population density and the degree of deforestation in the immediate area. We used CDC light traps to sample the area surrounding 24 households (6 households in each category). Samples were taken on six occasions during September-November 2009 and June-August 2010. A total of 3074 sand fly specimens were collected, including 1163 females and 1911 males. These were classified into 13 genera and 52 species. The greatest abundance of sand flies and the greatest richness of species were observed in areas where human population density was highest. Our results show that changes in the human occupancy and vegetation management in rural settlements may affect the population dynamics and distribution of sand fly species, thereby affecting the local transmission of cutaneous leishmaniases.

Calodium hepaticum: Household Clustering Transmission and the Finding of a Source of Human Spurious Infection in a Community of the Amazon Region

Background: Calodium hepaticum (syn. Capillaria hepatica) is a worldwide helminth parasite of which several aspects of transmission still remain unclear. In the Amazon region, the mechanism of transmission based on the ingestion of eggs present in the liver of wild mammals has been suggested as the cause of the spurious infections described. We performed an epidemiological investigation to determine the incidence, risk of spurious infection and the dynamics of transmission of C. hepaticum in a community of the Brazilian Amazon. Methodology/Principal Findings: Stool samples of 135 individuals, two dog feces and liver tissue from a peccary (captured and eaten by the residents) were analyzed by conventional microscopy. Dog feces were collected from the gardens of households presenting human cases of spurious C. hepaticum infections. Community practices and feeding habits related to the transmission of the parasite were investigated. The individual incidence of spurious infection was 6.7% (95% CI: 2.08–11.24). Cases of spurious infection were observed in 7.5% of the families and the household incidence was from 50% to 83.3%. The risk of spurious infection was 10-fold greater in persons consuming the liver of wild mammals (p = 0.02). The liver tissue of a peccary and one feces sample of a dog presented eggs of C. hepaticum. The consumption of the infected liver was the cause of the spurious infections reported in one household. Conclusions/Significance: This is the first identification of a source of spurious infection by C. hepaticum in humans and we describe a high rate of incidence in household clusters related to game liver alimentary habits. The finding of a dog feces contaminating peridomiciliary ground suggests the risk of new infections. We conclude that the mechanism of transmission based on the ingestion of liver is important for the dynamics of transmission of C. hepaticum in the studied area.

Unexpected high diversity of galling insects in the Amazonian upper canopy: the savanna out there.

A relatively large number of studies reassert the strong relationship between galling insect diversity and extreme hydric and thermal status in some habitats, and an overall pattern of a greater number of galling species in the understory of scleromorphic vegetation. We compared galling insect diversity in the forest canopy and its relationship with tree richness among upland terra firme, várzea, and igapó floodplains in Amazonia, Brazil. The soils of these forest types have highly different hydric and nutritional status. Overall, we examined the upper layer of 1,091 tree crowns. Galling species richness and abundance were higher in terra firme forests compared to várzea and igapó forests. GLM-ANCOVA models revealed that the number of tree species sampled in each forest type was determinant in the gall-forming insect diversity. The ratio between galling insect richness and number of tree species sampled (GIR/TSS ratio) was higher in the terra firme forest and in seasonally flooded igapó, while the várzea presented the lowest GIR/TSS ratio. In this study, we recorded unprecedented values of galling species diversity and abundance per sampling point. The GIR/TSS ratio from várzea was approximately 2.5 times higher than the highest value of this ratio ever reported in the literature. Based on this fact, we ascertained that várzea and igapó floodplain forests (with lower GIA and GIR), together with the speciose terra firme galling community emerge as the gall diversity apex landscape among all biogeographic regions already investigated. Contrary to expectation, our results also support the “harsh environment hypothesis”, and unveil the Amazonian upper canopy as similar to Mediterranean vegetation habitats, hygrothermically stressed environments with leaf temperature at lethal limits and high levels of leaf sclerophylly.

Comparison of the performance of two spontaneous sedimentation techniques for the diagnosis of human intestinal parasites in the absence of a gold standard

Performance evaluation of diagnostic tests is critical in the search for accurate diagnoses. A gold standard test is usually absent in parasitology, thus rendering satisfactory assessment of diagnostic accuracy difficult. Moreover, reliability (assessed by the study of repeatability) is a rarely studied characteristic of diagnostic tests. This study compared and evaluated the performance (repeatability, concordance and accuracy) of the spontaneous sedimentation technique (SST) and the Paratest for the diagnosis of Giardia lamblia, Entamoeba histolytica complex, Blastocystis spp., Ascaris lumbricoides, hookworm, Trichuris trichiura and Calodium hepaticum. Fecal samples of 143 individuals were separated into three replicates for each test. Concordance and homogeneity of the results between replicates of each test and between tests were evaluated. Proportions of positives, sensitivity and specificity were estimated using a Bayesian Latent Class Model. High repeatability of both tests was found for the detection of intestinal parasites, except for Blastocystis spp. and hookworm. Concordance between tests was generally high (concordance correlation coefficient, 0.72-0.88), except for Blastocystis spp., hookworm and T. trichiura. The Paratest detected more cases of Blastocystis spp. and fewer of hookworm than the SST. The tests were quite discordant in the detection of T. trichiura. A low sensitivity (39.4-49.2% for SST, 35.8-53.8% for Paratest) and a high specificity (93.2-97.2%) were found for both tests. The Paratest presented a slightly higher sensitivity for the diagnosis of Blastocystis spp. (53.8%), and SST did so for hookworm (49.2%). This is the first study on repeatability and accuracy (using a Bayesian approach) of two spontaneous sedimentation techniques. These results suggest underdiagnosis of little dense parasitic forms due to technical limitations in both tests. We conclude that the combined study of repeatability, concordance and accuracy is a key strategy for better evaluation of the performance of tests and is also useful for the identification of technical limitations.

Diversity of sand flies in domiciliary environment of Santarém, state of Pará, Brazil: species composition and abundance patterns in rural and urban areas

AbstrAct This paper aimed to evaluate the richness, abundance and frequency of sand fly occurrence in rural and urban areas American visceral leishmaniasis -AVL is endemic in the study area of Santarem municipality, Para state. Sand flies were collected during 1995-2000, using CDC light traps placed in neighborhoods and rural areas of the municipality. A total of 53.454 individuals and 26 species of sand flies were collected. The most abundant species in both urban and rural environments was Lutzomyia longipalpis , vector of AVL in the area. The highest species richness by capture was in rural area. In all years sampled, the largest number of species of sand fly collected was always in rural areas. The species of sand flies in urban and rural area were similar in 11 species. In the rural area other 11 species were found, a total of 22 species. Shannon-Wiener index ranged from 0.12 to 0.84 at rural areas and 0.08 to 0.34 at urban ones. In general, rural localities showed higher diversity (

Measuring Mosquito Diversity Patterns in an Amazonian Terra Firme Rain Forest

ABSTRACT We reanalyzed a dataset consisting of ≈10,700 crepuscular and night-biting female mosquitoes (Culicidae) collected over 12 mo in the canopy and understorey of primary Amazonian rain forest. We investigate whether vertical habitat stratification and rainfall modified major ecological parameters of this mosquito ensemble, combining descriptive and hypothesis-testing statistics with species richness and diversity metrics in the analyses. A total of 31 species was recorded. Contrary to expectations, the host-seeking mosquito fauna was less diverse in the forest canopy than in the understorey. In particular, species diversity and evenness were higher in understorey samples, whereas species richness estimates were similar in both habitats. Only two out of 12 species tested for vertical stratification were clearly acrodendrophilic, and five preferred understorey habitats. The mosquito fauna was more diverse in the rainy than in the dry season. We propose the hypothesis that female mosquito density and host defensive behavior may promote host seeking in nonpreferred habitats by acrodendrophilic mosquito species. These results may be particularly relevant for understanding the dynamics of Plasmodium malariae/brasilianum and arboviral infections in Amazonian forested landscapes.

Rudimentary cesspits as breeding sites for Aedes aegypti in urban areas of Northern Brazil

We evaluated rudimentary cesspits as potential breeding sites for the mosquito Aedes aegypti and mosquito production compared to those officially designated common breeding sites (CBS). In November and December of 2009, immature forms of the insect were collected in water samples of cesspits as well as of CBS, the latter being any object that potentially accumulates water such as used tires, flower pots and sites of solid waste disposal. Samplings were performed in urban areas of two municipalities of Rondonia State in the Brazilian Western Amazon. Immature and adult forms of Ae. aegypti were observed in cesspits confirming these as novel breeding sites for the mosquito in that region. The proportion of cess¬pits found with Ae. aegypti immature forms in the two surveyed localities were as follows: Espigao do Oeste, 50.0% and Jaru, 27.3%. Moreover, the average number of insects did not differ significantly in the sampled cesspits and CBS. These results provides subsidies for change in the policies and strategies of dengue vector control in Brazil, taking into account the limited sanitation infrastructure and the local particularities of the Amazon Region. They also point to the urgency of investments and adequacy of efforts in systems of public sanitation in developing countries, to aid in the control of this important vector of viral diseases.

Galling Insects in the Pantanal Wetland and Amazonian Rainforest

It were collected 133 morphospecies of galling insects on 75 host plant species in the Pantanal forest patches while studies compilation pointed the interesting record of 1,549 galling morphospecies in 66 botanical families, 251 genera and 713 species of host plants in the Amazonian forests. No difference was observed in the number of galling species between Pantanal patch edge and interior. However, dissimilarity in galling species composition was verified in the patch habitats. To date, galling insect fauna of Pantanal region have not been properly sampled. In the Amazonian forests and Pantanal wetlands, galling species richness was strongly affected by hygrothermal and nutritional stress, even though mediated by soil fertility, topography, and flooding. Upper canopy of the Amazonian rainforests was the most speciose environment for galling fauna. Their microclimatic conditions, similar to scleromorphic/sclerophyllous vegetations, favor the attack by these herbivores. Besides, the Amazonian super-host and host/non-host plant diversity seems to play an important role on the richness and distribution patterns of galling insects.

Influence of Flood Levels on the Richness and Abundance of Galling Insects Associated with Trees from Seasonally Flooded Forests of Central Amazonia, Brazil

We reexamined three hypotheses - “Nutritional stress hypothesis,” “Hydric stress hypothesis,” and “Plant species richness hypothesis” – which addressed galling insect abundance and richness in the canopies of igapo and varzea forests, considering different flooding levels (high and low quota). The collections were made at the Mamiraua and Amana Reserves, Brazil. In the varzea 26,244 galls were collected, corresponding to 297 species of galling insects; 23,994 galls were sampled in the igapo and identified as 235 galling species. The forest type and habitat (flooding level) had no significant effect on galling insect abundance. However, the interaction between these explanatory variables accounted for the variance on galling insect richness (GIR). High/low igapo categories presented larger values of the ratio between galling insect richness and tree richness, when compared to high/low varzea forests. The number of tree species was responsible for 82% of the variation in varzea GIR, while in the igapo a smaller value - 70% - was observed. Our findings indicated that local nutrient availability (igapo and varzea), flood levels, and their interaction affect both insects and plants, as well as their ecological relationships.