[Ecology of mosquitoes (Diptera: Culicidae) in areas of Serra da Bocaina National Park, Brazil. I. Habitat distribution]

Monthly abundance and diversity of mosquitoes (Diptera: Culicidae) in an Atlantic Forest area of Rio de Janeiro, Brazil

Several mosquito species in the Atlantic Forest are yellow fever vectors; therefore, this biome can represent a potential risk to the human population. Studies on mosquitoes from predominantly sylvatic areas produce valuable data for understanding the emergence of new epidemics. In addition, they can elucidate environmental components favoring or hindering biodiversity and species distribution. Our study aimed to evaluate the monthly distribution, composition, diversity, and influence of seasonal periods (dry and rainy) on the mosquito fauna. We used CDC light traps at different levels in a forest area bordering a Conservation Unit of Nova Iguaçu in the state of Rio de Janeiro, Brazil. Specimens were collected from August 2018 to July 2019 by installing traps in sampling sites under different vegetation covers. We detected some species of epidemiological importance in terms of arbovirus transmission. A total of 4,048 specimens representing 20 different species were collected. Among them, Aedes (Stg.) albopictus Skuse, 1894 showed recurrent association with the closest level to human residences and Haemagogus (Con.) leucocelaenus Dyar and Shannon, 1924 with the most distant levels. Since these mosquitoes are possible vectors of yellow fever, monitoring the area is extremely important. Under the studied conditions, the mosquito populations were directly influenced by dry and rainy periods, posing a risk to the nearby resident population.

Cardoso J, Gonçalves-dos-Santos ME, Oliveira RS, Aquino-Teixeira SM, Campos AAS, Almeida MAB, Simonini-Teixeira D, da P. Sevá A, Temponi AOD, Magalhães FM, da Silva Menezes AS, Lopes BT, Almeida HP, Pedroso AL, Gonçalves GP, Chaves DCC, de Menezes GG, Bernal-Valle S, Müller NFD, Janssen L, dos Santos E, Mares-Guia MA, Albuquerque GR, Romano APM, Franco AC, Ribeiro BM, Roehe PM, Lourenço-de-Oliveira R, de Abreu FVS. Yellow Fever Virus Maintained by Sabethes Mosquitoes during the Dry Season in Cerrado, a Semiarid Region of Brazil, in 2021

In recent decades, waves of yellow fever virus (YFV) from the Amazon Rainforest have spread and caused outbreaks in other regions of Brazil, including the Cerrado, a savannah-like biome through which YFV usually moves before arriving at the Atlantic Forest. To identify the vectors involved in the maintenance of the virus in semiarid environments, an entomological survey was conducted after confirmation of yellow fever (YF) epizootics at the peak of the dry season in the Cerrado areas of the state of Minas Gerais. In total, 917 mosquitoes from 13 taxa were collected and tested for the presence of YFV. Interestingly, mosquitoes of the Sabethes genus represented 95% of the diurnal captured specimens, displaying a peak of biting activity never previously recorded, between 4:30 and 5:30 p.m. Molecular analysis identified three YFV-positive pools, two from Sabethes chloropterus-from which near-complete genomes were generated-and one from Sa. albiprivus, whose low viral load prevented sequencing. Sa. chloropterus was considered the primary vector due to the high number of copies of YFV RNA and the high relative abundance detected. Its bionomic characteristics allow its survival in dry places and dry time periods. For the first time in Brazil, Sa. albiprivus was found to be naturally infected with YFV and may have played a role as a secondary vector. Despite its high relative abundance, fewer copies of viral RNA were found, as well as a lower Minimum Infection Rate (MIR). Genomic and phylogeographic analysis showed that the virus clustered in the sub-lineage YFVPA-MG, which circulated in Pará in 2017 and then spread into other regions of the country. The results reported here contribute to the understanding of the epidemiology and mechanisms of YFV dispersion and maintenance, especially in adverse weather conditions. The intense viral circulation, even outside the seasonal period, increases the importance of surveillance and YFV vaccination to protect human populations in affected areas.

Prevalence of Mosquito Populations in the Caribbean Region of Colombia with Important Public Health Implications

Mosquito studies are important for understanding their role in the transmission of pathogens including arboviruses, parasites, and protozoa. This study characterized the prevalence of Culicidae fauna in rural and peri-urban areas with human populations in the Colombian Caribbean region to establish the risk of transmission of mosquito-borne pathogens. From 2016 to 2017, adult mosquitos were collected in Turbaco (Bolívar), Sabanalarga (Atlántico) and Pueblo Bello (Cesar). The collections in rural areas were in the forest fragments using CDC, Shannon, and human bait traps. In peri-urban areas, Prokopack aspirator collections were used inside households. Entomological and ecological indicators were also calculated. A total of 11,566 mosquito specimens, from 13 genera and 63 species, were collected. The forests fragments of Sabanalarga and Turbaco had the highest species abundance and richness. Turbaco had the highest adult Aedes aegypti index. Arbovirus vectors were among the identified species, including Ae. aegypti, Culex quinquefasciatus, Haemagogus janthinomys, Sabethes chloropterus, Aedes angustivittatus, Mansonia titillans, Coquillettidia venezuelensis and the subgenera Culex Melanoconion. Overall, the diversity and abundance of mosquitoes present in these municipalities establish a potential disease transmission risk by these vectors.

Spatial distribution and interactions between mosquitoes (Diptera: Culicidae) and climatic factors in the Amazon, with emphasis on the tribe Mansoniini

This work aimed to evaluate the spatial distribution of mosquitoes in different seasonal periods and the interaction between climatic factors and the abundance of mosquitoes, especially those belonging to the tribe Mansoniini in the area surrounding the Amazon hydroelectric production region (Jirau-HP) of Rondônia state, Brazil. Mosquito specimens were collected in May, July, October, and December 2018, and April, July, September, and November 2019, over periods of three alternating days during the hours of 6:00 p.m. to 8:00 p.m. Mosquito sampling was performed using automatic CDC and Shannon light traps. Canonical correspondence analysis (CCA), combined with Monte Carlo permutations, was used to evaluate the correlation between climatic variables and species distribution. In addition, non-metric multidimensional scaling (NMDS) was used to verify the similarity among the sampled communities from the different collections. After analyzing the total mosquito fauna at all sampling points, 46,564 specimens were identified, with Mansonia dyari showing the highest relative abundance in 2018 (35.9%). In contrast, Mansonia titillans had the highest relative abundance in 2019 (25.34%), followed by Mansonia iguassuensis (24.26%). The CCA showed that maximum temperature significantly influenced the distribution of mosquito populations in the study area (p = 0.0406). The NMDS showed that sampling carried out in the rainy and dry seasons formed two distinct groups. There was a significant correlation between species richness and cumulative precipitation 15 days before the sampling period (R² = 58.39%; p = 0.0272). Thus, both temperature and precipitation affected mosquito population dynamics. The effect of rainfall on mosquito communities may be due to variations in habitat availability for immature forms.

Detection and molecular characterization of Avipoxvirus in Culex spp. (Culicidae) captured in domestic areas in Rio de Janeiro, Brazil

Avian pox is a highly contagious poultry disease that causes significant economic losses. Mosquitoes belonging to the genus Culex (Diptera: Culicidae) have a fundamental role in disseminating Avipoxvirus (Poxviridae). This study proposes investigating the presence of Avipoxvirus (APV) DNA in Culex spp. from Rio de Janeiro to determine its frequency and perform a phylogenetic analysis based on the core like the 4b protein (p4b) gene. The detection of APVs was conducted individually on four hundred Culex spp. mosquitoes. A total of 12.23% (47/384) of the Culex spp. were positive in the PCR. Sequencing the p4b gene revealed that this study’s sequences displayed 98.8–99% identity with Fowlpoxvirus (FWPW) sequences available in GenBank. In the phylogenetic analysis, these APVs were clustered in the A1 subclade together with FWPW sequences from several countries. The evolutionary distance of the p4b gene was 0.61 ± 0.21% in rural areas and 0.38 ± 0.16% in peri-urban areas. The current investigation is the first study to report the detection of APVs in field-caught mosquitoes. Moreover, a high frequency of APV DNA was observed in Culex spp. captured in domestic areas, where backyard poultry is present. This data demonstrates the importance of implementing control measures for Culex spp. to mitigate the transmission of APVs in backyard poultry in Rio de Janeiro.

Diversity of Mosquitoes (Diptera: Culicidae) in the Bom Retiro Private Natural Heritage Reserve, Rio de Janeiro State, Brazil

This study registers the diversity of Culicidae in the Bom Retiro Private Natural Heritage Reserve (RPPNBR), Rio de Janeiro state, Brazil, based on the collection of the immature stages in natural and artificial larval habitats. Larvae and pupae were collected monthly at two sites of the RPPNBR from May 2014 to July 2015 using dippers and aquatic pipettes. The diversity of the mosquito community was described using the Shannon-Wiener Diversity Index (H'), as well as diversity, richness, and dominance of species found in different larval habitats (lake, bamboos, bromeliads, and artificial vessels). The Mann-Whitney test was used to calculate differences between the two natural and artificial habitats. Overall, 15,659 specimens belonging to 25 species, ten genera, and two subfamilies were collected. The most abundant species collected at sites that were reforested recently were Culex pleuristriatus Theobald, 1903, Limatus durhamii (Theobald, 1901), Aedes albopictus (Skuse, 1895), Culex neglectus (Lutz, 1904), and Culex retrosus (Lane & Whitman, 1951). In a forest preserved site, the most abundant species were Cx. neglectus, Culex iridescens (Lutz, 1905), Sabethes identicus (Dyar & Knab, 1907), Wyeomyia arthrostigma (Lutz, 1905), and Li. durhamii. With respect to larval habitats, 0.1% of the specimens were collected along the edge of a lake, 5.5% in bamboos, 35.9% in bromeliads, and 58.4% in artificial containers. Only 5.5% of the specimens were collected in the forest preserved site, with the remaining samples from the site with altered vegetation. A greater species richness and diversity were found in forest-altered sites compared to the forest preserved site. Several species were collected in the water accumulated in the nylon lids of plastic water tanks. Such vessels can promote an increase in mosquito population density in the environment surrounding the study area.

Single-round multiplex PCR with species-specific mitochondrial primers of P. falciparum, P. vivax/P. simium and P. malariae/P. brasilianum: Comparison with standard techniques

A single-round multiplex PCR (mPCR) with species-specific primers (SSP) of three mitochondrial genes of Plasmodium, namely COX I, COX III and CYT B, was compared to microscopy and 18S rRNA semi-nested PCR, nested-PCR and Real Time PCRs (*PCRs). Each parasite has between 20 and 150 mitochondria and each mitochondria has one copy of each target gene, while 18S rRNA gene is repeated 4 to 8 times. The specificity of mPCR was assessed by testing Plasmodium from rodents and birds, parasites responsible for other endemic diseases in the country such as schistosomiasis, Chagas disease and leishmaniasis in addition to microorganisms that, like Plasmodium, can cause anemia (Bartonella henselae, Babesia vogeli, Rickettsia vini). No cross-reactions were detected. From a total of 149 specimens from suspected cases of malaria were tested, 97 were positive by microscopy (49 P. falciparum, 38 P. vivax, 6 P. malariae, 4 P. falciparum/P. vivax- mixed infections) and 52 were negative; 148 samples were positive by *PCRs (49 P. falciparum, 53 P. vivax, 7 P. malariae and 39 mixed infections) and one was negative; 146 were positive by mPCR (49 P. falciparum, 56 P. vivax, 9 P. malariae and 32 mixed infections) and three were negative. The comparison of groups found statistically significant differences between microscopy vs.*PCRs or vs. mPCR (p-values <0.0001), but no difference was found between mPCR vs. *PCRs (p=0.946). The agreement in the identification of Plasmodium species was only regular, with Kappa indices of 0.407 (microscopy vs. *PCRs), 0.433 (microscopy vs. mPCR) and 0.558 (*PCRs vs. mPCR). In conclusion, the diagnostic performance of mPCR was comparable to those of *PCRs, and superior to microscopy, although the identification of Plasmodium species showed many disagreements. In conclusion, a sensitive and specific one-round SSP multiplex PCR, capable of simultaneously detecting and identifying P. falciparum, P. vivax/P. simium and P. malariae/P. brasilianum may be useful in resource-constrained countries where quantitative amplifications are not yet fully accessible.

Composition and distribution of fishes from the Perequê-Açu river basin, Paraty, Rio de Janeiro, Southeastern Brazil

Abstract The large number of less-known coastal drainages in the Atlantic Forest still represents an important gap in the knowledge of ichthyofauna. It is evaluated the taxonomic diversity, frequency and constancy of occurrence, and the distribution of species in the various segments of the Perequê-Açu river basin, state of Rio de Janeiro, Brazil. Twelve sampling campaigns resulted in 13,423 individuals, belonging to seven orders, 10 families, 21 genera, and 23 native species. Cyprinodontiformes and Siluriformes represented about 87.2% of the total abundance, mainly due to the contribution of Phalloceros anisophallos and Schizolecis guntheri, which account for 63.2% of the total sampled individuals. The analysis of constancy of occurrence reveals that 78.3% of the drainage species are residents, with approximately 93% of the residents of the Carrasquinho River sub-basin. The Sertões River sub-basin had the largest number of species in total: 18. The rarefaction curve did not reach an asymptote, although Chao 2 and bootstrap estimate the richness of 23.9 species and 23.7 species, respectively. The results of PERMANOVA, PCoA, and SIMPER indicate that the fish composition along the catchment is not homogeneous. The conservation status of species is also discussed, regionally, nationally, and globally.

Diversity of Mosquitoes At the Itatiaia National Park, State of Rio De Janeiro, Brazil

A temporal observational study was conducted with the aim of characterizing Culicidae richness, diversity, abundance, and species similarity in fragments of Atlantic Forest within the Itatiaia National Park, state of Rio de Janeiro, Brazil. A total of 31 mosquito species were collected in 2 sampling stations, during the day and night, and the abundance index and dominance coefficient for each species were calculated. The results showed that the culicid density was higher during the day, and the time preference was directly influenced by the climate variables analyzed, which acted as limiting factors for mosquito occurrence. The mosquito fauna at the Itatiaia National Park presented high richness, including some epidemiologically important species: Anopheles cruzii, Haemagogus leucocelaenus, Aedes scapularis, and Sabethes identicus. Studies of this region supply information on biodiversity, and consequently help to understand epidemiological aspects of potential pathogen vector species.

Enzootic mosquito vector species at equine encephalitis transmission foci in the República de Panamá

The identification of mosquito vector species present at arboviral enzootic transmission foci is important to understand transmission eco-epidemiology and to propose and implement prevention and control strategies that reduce vector-borne equine encephalitis transmission. The goal of this study was to identify mosquito species potentially involved in the transmission of enzootic equine encephalitis, in relation to their abundance and diversity at three endemic regions in the República de Panamá. We sampled adult mosquitoes during the dry and rainy season of Panamá. We employed CDC light traps with octanol, EV traps with CO₂ and Trinidad 17 traps baited with live hamsters. Traps were deployed in the peridomicile and extradomicile of houses from 18:00 to 6:00 h. We estimated the abundance and diversity of sampled species. We collected a total of 4868 mosquitoes, belonging to 45 species and 11 genera, over 216 sampling nights. Culex (Melanoconion) pedroi, a major Venezuelan equine encephalitis vector was relatively rare (< 2.0% of all sampled mosquitoes). We also found Cx. (Mel) adamesi, Cx. (Mel) crybda, Cx. (Mel) ocossa, Cx. (Mel) spissipes, Cx. (Mel) taeniopus, Cx. (Mel) vomerifer, Aedes scapularis, Ae. angustivittatus, Coquillettidia venezuelensis, Cx. nigripalpus, Cx. declarator, Mansonia titillans, M. pseudotitillans and Psorophora ferox all species known to be vectorially competent for the transmission of arboviruses. Abundance and diversity of mosquitoes in the sampled locations was high, when compared with similar surveys in temperate areas. Information from previous reports about vectorial competence / capacity of the sampled mosquito species suggest that sampled locations have all the elements to support enzootic outbreaks of Venezuelan and Eastern equine encephalitides.

Development of a benthic multimetric index for the Serra da Bocaina bioregion in Southeast Brazil

Brazil faces a challenge to develop biomonitoring tools to be used in water quality assessment programs, but few multimetric indices were developed so far. This study is part of an effort to test and implement programs using benthic macroinvertebrates as bioindicators in Rio de Janeiro State. Our aim was first to test the Multimetric Index for Serra dos Órgãos (SOMI) for a different area - Serra da Bocaina (SB) - in the same ecoregion. We sampled 27 streams of different sizes and altitudes in the SB region. Despite the environmental similarities, results indicated biological differences between reference sites of the two regions. Considering these differences, we decided to develop an index specific for the SB region, the Serra da Bocaina Multimetric Index (MISB). We tested twenty-two metrics for sensitivity to impairment and redundancy, and six metrics were considered valid to integrate the MISB: Family Richness, Trichoptera Richness, % Coleoptera, % Diptera, IBE-IOC index, EPT / Chironomidae ratio. A test of the MISB in eleven sites indicated it was more related to land-use and water physico-chemical parameters than with altitude or stream width, being a useful tool for the monitoring and assessment of streams in the bioregion.

Immature mosquitoes of Serra do Mar park, Sao Paulo State, Brazil

With the objective of providing knowledge about the natural habitat of mosquito larvae, we conducted a study on the culicid fauna and identified larval habitat types at 3 different locations in the Serra do Mar State Park, Brazil, over the 12 months of 1991. We collected 1,425 larvae belonging to 23 species, of which the most frequent were Culex iridescens, Culex spp., Limatus durhami, and Trichoprosopon pallidiventer. The mosquito larval habitats presenting the greatest densities of specimens were bamboo, bromeliads, rubber boots, and streams. We observed that the culicids used a variety of containers as larval habitats and bred under a diversity of ecological conditions. Most of the habitats were natural, formed by bamboo, bromeliads, streams, and depressions in the ground and in rocks, along with artificial habitats consisting of rubber boots and abandoned metal cans. Seven species occurred preferentially in the internodes of closed bamboo stems, 6 in internodes of open stems, and 4 in bromeliads.

Aquatic macroinvertebrate diversity and composition in streams along an altitudinal gradient in Southeastern Brazil

Aquatic macroinvertebrate diversity and composition in streams along an altitudinal gradient in Southeastern Brazil. A study concerning taxonomic richness and composition of the aquatic insect fauna in streams within the same catchment basin along an altitudinal gradient in Southeast Brazil, was conducted to test the hypothesis that there is a faunal discontinuity in the biocenotic composition, related to differences in altitude and latitude. In Southeastern Brazil, around latitude 22°, this faunal transition from rhithron to potamon biocenosis should occur at 500 m above sea level. Eighteen tributaries of the Mambucaba River, at Serra da Bocaina National Park, SP-RJ, Brazil, were studied. The streams were separated into 6 altitudinal zones (zone 1: above 1500 m; zone 2: 1200-1300 m; zone 3: 900-1000 m; zone 4: 400-700 m; zone 5: 100-300 m; and zone 6: 0-100 m) each including three streams. The aquatic insects were identified at the lowest possible taxonomic level. The highest richness was observed in altitudes between 1200-1300 m, while the lowest occurred in altitudes below 100 m. The Indicator Value method indicated taxa characteristic for four of the six altitudinal zones considered in this paper. Sorensen's Index and CCA results showed that distribution and composition of aquatic insect fauna of Serra da Bocaina National Park was influenced primarily by altitude and temperature rather than stream size. The absence of indicator species and the lower abundance in altitudes between 400-700 m suggest a transition from rhithral to potamal fauna, which is distinct at 200 m.

Inventário de mosquitos (Diptera: Culicidae) da Unidade de Conservação Ambiental Desterro, Ilha de Santa Catarina, Sul do Brasil

Dois mil e sessenta e um espécimes distribuídos em 36 espécies de mosquitos foram coletadas entre agosto de 2007 e maio de 2008 na Unidade de Conservação Ambiental Desterro (localizada no Estado de Santa Catarina, Brasil). As cinco espécies mais abundantes foram: Runchomyia reversa (29,74%), Ochlerotatus scapularis (14,80%), Wyeomyia pallidoventer (9,51%), Anopheles cruzii (8,30%) e Sabethes purpureus (7,03%). São registradas dez novas espécies de Culicidae para o Estado de Santa Catarina, sendo que dessas, seis pertencentes ao gênero Wyeomyia.

Kerteszia subgenus of Anopheles associated with the Brazilian Atlantic rainforest:current knowledge and future challenges

BACKGROUND

The Atlantic rainforest ecosystem, where bromeliads are abundant, provides an excellent environment for Kerteszia species, because these anophelines use the axils of those plants as larval habitat. Anopheles (K.) cruzii and Anopheles (K.) bellator are considered the primary vectors of malaria in the Atlantic forest. Although the incidence of malaria has declined in some areas of the Atlantic forest, autochthonous cases are still registered every year, with Anopheles cruzii being considered to be a primary vector of both human and simian Plasmodium.

METHODS

Recent publications that addressed ecological aspects that are important for understanding the involvement of Kerteszia species in the epidemiology of malaria in the Atlantic rainforest in the Neotropical Region were analysed.

CONCLUSION

The current state of knowledge about Kerteszia species in relation to the Atlantic rainforest ecosystem was discussed. Emphasis was placed on ecological characteristics related to epidemiological aspects of this group of mosquitoes. The main objective was to investigate biological aspects of the species that should be given priority in future studies.

Epidemiologic aspects of the malaria transmission cycle in an area of very low incidence in Brazil

BACKGROUND

Extra-Amazonian autochthonous Plasmodium vivax infections have been reported in mountainous regions surrounded by the Atlantic Forest in Espírito Santo state, Brazil.

METHODS

Sixty-five patients and 1,777 residents were surveyed between April 2001 and March 2004. Laboratory methods included thin and thick smears, multiplex-PCR, immunofluorescent assay (IFA) against P. vivax and Plasmodium malariae crude blood-stage antigens and enzyme-linked immunosorbent assay (ELISA) for antibodies against the P. vivax-complex (P. vivax and variants) and P. malariae/Plasmodium brasilianum circumsporozoite-protein (CSP) antigens.

RESULTS

Average patient age was 35.1 years. Most (78.5%) were males; 64.6% lived in rural areas; 35.4% were farmers; and 12.3% students. There was no relevant history of travel. Ninety-five per cent of the patients were experiencing their first episode of malaria. Laboratory data from 51 patients were consistent with P. vivax infection, which was determined by thin smear. Of these samples, 48 were assayed by multiplex-PCR. Forty-five were positive for P. vivax, confirming the parasitological results, while P. malariae was detected in one sample and two gave negative results. Fifty percent of the 50 patients tested had IgG antibodies against the P. vivax-complex or P. malariae CSP as determined by ELISA. The percentages of residents with IgM and IgG antibodies detected by IFA for P. malariae, P. vivax and Plasmodium falciparum who did not complain of malaria symptoms at the time blood was collected were 30.1% and 56.5%, 6.2% and 37.7%, and 13.5% and 13%, respectively. The same sera that reacted to P. vivax also reacted to P. malariae. The following numbers of samples were positive in multiplex-PCR: 23 for P. vivax; 15 for P. malariae; 9 for P. falciparum and only one for P. falciparum and P. malariae. All thin and thick smears were negative. ELISA against CSP antigens was positive in 25.4%, 6.3%, 10.7% and 15.1% of the samples tested for "classical" P. vivax (VK210), VK247, P. vivax-like and P. malariae, respectively. Anopheline captures in the transmission area revealed only zoophilic and exophilic species.

CONCLUSION

The low incidence of malaria cases, the finding of asymptomatic inhabitants and the geographic separation of patients allied to serological and molecular results raise the possibility of the existence of a simian reservoir in these areas.

Ecosystem approaches and health in Latin America

Important environmental changes that have become increasingly pronounced in the last two centuries and that are seriously affecting human health require the development of integrated and participatory scientific approaches that can result in proposals for institutional and public policy changes. The purpose of this article is to offer some elements that can contribute to a line of reflection based on studies with ecosystem approaches in the Latin America context. The authors begin with a brief description of current scientific literature in public health that links ecosystems and human health in Latin America; next, they describe and compare the two prevailing trends that form the basis for the theoretical and methodological debates on ecosystem approaches; they also review the empirical research in Latin America or concerning Latin American countries in which an ecosystem approach has been adopted. The results point to limited scientific output on the interface between ecosystems and human health; aspects involving public participation and implementation of institutional changes and public policies are still in a rather incipient stage.

Imaturos de Culicidae (Diptera) encontrados em recipientes instalados em mata residual no munícipio de Londrina, Paraná, Brasil

Fragmentos de mata na área urbana ou periurbana podem ser locais favoráveis a procriação de Culicidae. Esse trabalho teve como objetivo levantar as espécies de culicídeos que utilizam criadouros artificiais, suas coexistência e as flutuações populacionais em uma reserva de mata localizada em Londrina - PR. Realizou-se coletas quinzenais de outubro de 1995 a setembro de 1996 em pneus e internódios de bambu armadilha que foram instalados ao nível do solo e outros internódios instalados a 2 m de altura. Coletou-se 12.656 espécimes, pertencentes a cinco gêneros e 11 espécies. As espécies mais abundantes nos criadouros foram Limatus durham Theobald, 1901, Culex eduardoi Casal & Garcia, 1968, Aedes terrens (Walker, 1856), Culex quinquefasciatus Say, 1823 e Aedes albopictus (Skuse, 1894). O maior número de indivíduos foi coletado em pneus, sendo que Limatus durham e Aedes terrens, apresentaram preferência nesse criadouro. A presença de Aedes aegypti (Linnaeus, 1762), Aedes albopictus e Haemagogus leucocelaenus (Dyar & Shannon, 1924) em diferentes coletas indica que esse tipo de ambiente não deve ser ignorado nas ações de controle de vetores, merecendo constante monitoramento.

[Spatial distribution of Anopheles pseudopunctipennis in the Yungas de Salta rainforest, Argentina]

OBJECTIVE

To compare the abundance of Anopheles pseudopunctipennis and other anopheline mosquitoes in three different wild areas, modified by human activities, and to verify how environmental differences affect the spatial distribution of these mosquitoes.

METHODS

Samples were collected monthly from December 2001 to December 2002 in Yungas de Salta, Argentina. CO2 -baited CDC light traps were placed at each sample site (forest, transition area and peridomiciliary area). In the peridomiciliary area, two agents also suctioned mosquitoes from house walls. Species diversity and abundance indices were estimated and the study sample sites were compared by ANOVA, cosine calculations and cluster analyses.

RESULTS

Anopheles pseudopunctipennis was the most abundant species. An. argyritarsis, An. nuneztovari, An. rangeli and An. strodei were also collected. Except for An. nuneztovari that was not captured in the peridomiciliary area, the other species were collected in the three different environments. There were no differences in the diversity indices and between sample sites. However, the cluster analysis showed the transition area to be more abundant for all species.

CONCLUSIONS

The highest abundance of species was found in the transition area, which, besides the peridomiciliary area, is the main area of risk for malarial transmission.

[Mosquito (Diptera, Culicidae) ecology in the Iguaçu National Park, Brazil: 1 Habitat distribution]

A study of the mosquito fauna in the Iguaçu National Park focused on population behavior in four biotopes with different types of plant cover inside the Park. Systematic bimonthly diurnal and nocturnal human bait and Shannon trap captures were conducted in both forest and domiciliary environments over the course of 24 months. A total of 20,273 adult mosquito specimens belonging to 44 species were collected: Ochlerotatus serratus (10.3%), Haemagogus leucocelaenus (9.7%), Mansonia titillans (9.6%), and Chagasia fajardoi (8.8%) were the most frequently captured mosquitoes. Anopheles cruzii, Runchomyia theobaldi, Wyeomyia aporonoma, and Wy. confusa were captured almost exclusively in well-preserved areas with dense forest cover. Culex nigripalpus, Oc. pennai, Oc. serratus, Sabethes purpureus, and Sa. albiprivus were captured in three essentially sylvatic biotopes. Species captured in the forest areas around a dam were: An. albitarsis s.l., An. galvaoi, An. evansae, An. fluminensis, Coquillettidia venezuelensis, Cq. juxtamansonia, Wy. quasilongirostris, and Onirion personatum, Ch. fajardoi, Cq. fasciolata, Cq nitens, and Ma. titillans were the most frequently captured species in a residential area.

[Ecology of mosquitoes in areas of the National Park of "Serra da Bocaina", Brazil: II - Monthly frequency and climatic factors]

OBJECTIVE

To establish the influence of climatic factors on the monthly frequency of mosquito fauna in areas of the National Park of Serra da Bocaina, Brazil.

METHODS

Human bait collections were conducted once a month, in diurnal and nocturnal hours, throughout 24 months, from January 1991 to December 1992.

RESULTS

A total of 11,808 adult mosquitoes belonging to 28 different species were collected. Anopheles cruzii, Runchomyia reversa, and Ru. frontosa were the most commonly found species each month. An. cruzii was found mostly from October to February; Ru. reversa and Ru. frontosa predominated in September. An. lutzi, Chagasia fajardoi, Coquillettidia chrysonotum, Aedes serratus, Trichoprosopon simile, Wyeomyia theobaldi, Ru. humboldti, and Ru. theobaldi are the second most prevalent species and they were found mostly throughout the hottest, rainiest and most humid months. Temperature and rainfall have positively influenced the incidence of the majority of the species.

CONCLUSIONS

The exuberant and well-preserved tropical forest of Mata Atlântica, rainfalls, and temperatures had a direct and significant contribution to the mosquito fauna in the park. In the months with greater rainfalls, temperatures and humidity, there was an increase in the density and diversity of mosquito species. The period from September to March was the most favorable for their proliferation. In the colder and drier period, from April to August, about 70% of the species showed a significant decline in number, and they were hardly found during these months.