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

Molecular Analysis Reveals a High Diversity of Anopheline Mosquitoes in Yanomami Lands and the Pantanal Region of Brazil

Identifying the species of the subfamily Anophelinae that are Plasmodium vectors is important to vector and malaria control. Despite the increase in cases, vector mosquitoes remain poorly known in Brazilian indigenous communities. This study explores Anophelinae mosquito diversity in the following areas: (1) a Yanomami reserve in the northwestern Amazon Brazil biome and (2) the Pantanal biome in southwestern Brazil. This is carried out by analyzing cytochrome c oxidase (COI) gene data using Refined Single Linkage (RESL), Assemble Species by Automatic Partitioning (ASAP), and tree-based multi-rate Poisson tree processes (mPTP) as species delimitation approaches. A total of 216 specimens collected from the Yanomami and Pantanal regions were sequenced and combined with 547 reference sequences for species delimitation analyses. The mPTP analysis for all sequences resulted in the delimitation of 45 species groups, while the ASAP analysis provided the partition of 48 groups. RESL analysis resulted in 63 operational taxonomic units (OTUs). This study expands our scant knowledge of anopheline species in the Yanomami and Pantanal regions. At least 18 species of Anophelinae mosquitoes were found in these study areas. Additional studies are now required to determine the species that transmit Plasmodium spp. in these regions.

Kerteszia cruzii and extra-Amazonian malaria in Brazil: Challenges due to climate change in the Atlantic Forest

Kerteszia cruzii is a sylvatic mosquito and the primary vector of Plasmodium spp., which can cause malaria in humans in areas outside the Amazon River basin in Brazil. Anthropic changes in the natural environments are the major drivers of massive deforestation and local climate change, with serious impacts on the dynamics of mosquito communities and on the risk of acquiring malaria. Considering the lack of information on the dynamics of malaria transmission in areas across the Atlantic Forest biome, where Ke. cruzii is the dominant vector, and the impact of climate drivers of malaria, the present study aimed to: (i) investigate the occurrence and survival rate of Ke. cruzii based on the distinct vegetation profiles found in areas across the coastal region of the Brazilian Atlantic Forest biome; (ii) estimate the extrinsic incubation period (EIP) and survival rates of P. vivax and P. falciparum parasites in Ke. cruzii under current and future scenarios. The potential distribution of Plasmodium spp. was estimated using simulation analyses under distinct scenarios of average temperature increases from 1 °C to 3.7 °C. Our results showed that two conditions are necessary to explain the occurrence and survival of Ke. cruzii: warm temperature and presence of the Atlantic Forest biome. Moreover, both Plasmodium species showed a tendency to decrease their EIP and increase their estimated survival rates in a scenario of higher temperature. Our findings support that the high-risk malaria areas may include the southern region of the distribution range of the Atlantic Forest biome in the coming years. Despite its limitations and assumptions, the present study provides robust evidence of areas with potential to be impacted by malaria incidence in a future scenario. These areas should be monitored in the next decades regarding the occurrence of the mosquito vector and the potential for malaria persistence and increased occurrence.

Tree hole mosquito species composition and relative abundances differ between urban and adjacent forest habitats in northwestern Argentina

Water-holding tree holes are main larval habitats for many pathogen vectors, especially mosquitoes (Diptera: Culicidae). Along 3 years, the diversity and composition of mosquito species in tree holes of two neighbouring but completely different environments, a city and its adjacent forest, were compared using generalized linear mixed models, PERMANOVA, SIMPER and species association indexes. The city area (Northwest Argentina) is highly relevant epidemiologically due to the presence of Aedes aegypti L. (main dengue vector) and occurrence of dengue outbreaks; the Yungas rainforests are highly biologically diverse. In total seven mosquito species were recorded, in descending order of abundance: Ae. aegypti, Haemagogus spegazzinii Brèthes, Sabethes purpureus (Theobald), Toxorhynchites guadeloupensis Dyar and Knab, Aedes terrens Walker, Haemagogus leucocelaenus Dyar & Shannon and Sabethes petrocchiae (Shannon and Del Ponte). The seven mosquito species were recorded in both city sites and forested areas; however, their mosquito communities significantly diverged because of marked differences in the frequency and relative abundance of some species: Tx. guadeloupensis and Ae. aegypti were significantly more abundant in forest and urban areas, respectively. Positive significant associations were detected between Ae. aegypti, Hg. spegazzinii and Hg. leucocelaenus. The combined presence of Ae. aegypti, Haemagogus and Sabethes in the area also highlight a potential risk of yellow fever epidemics. Overall results show an impoverished tree hole mosquito fauna in urban environments, reflecting negative effects of urbanization on mosquito diversity.

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.

Forest litter crickets prefer higher substrate moisture for oviposition: Evidence from field and lab experiments

For insects, choosing a favorable oviposition site is a type of parental care, as far as it increases the fitness of its offspring. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate moisture. However, lab experiments with mole crickets showed a linear oviposition response to substrate moisture. Studies with the house cricket Acheta domesticus also showed a linear juvenile body growth response to water availability, thus adult ovipositing females should respond positively to substrate moisture. We used a field experiment to evaluate the relationship between oviposition preference and substrate moisture in forest litter-dwelling cricket species. We also evaluated oviposition responses to substrate moisture level in Ubiquepuella telytokous, the most abundant litter cricket species in our study area, using a laboratory study. We offered cotton substrate for oviposition which varied in substrate moisture level from zero (i.e., dry) to maximum water absorption capacity. We used two complementary metrics to evaluate oviposition preference: (i) presence or absence of eggs in each sampling unit as binary response variable, and (ii) number of eggs oviposited per sampling unit as count response variable. To test for non-linear responses, we adjusted generalized additive models (GAMM) with mixed effects. We found that both cricket oviposition probability and effort (i.e., number of eggs laid) increased linearly with substrate moisture in the field experiment, and for U. telytokous in the lab experiment. We discarded any non-linear responses. Our results demonstrate the importance of substrate moisture as an ecological niche dimension for litter crickets. This work bolsters knowledge of litter cricket life history association with moisture, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying.

Filarial nematodes with zoonotic potential in ring-tailed coatis (Nasua nasua Linnaeus, 1766, Carnivora: Procyonidae) and domestic dogs from Iguaçu National Park, Brazil

Iguaçu National Park, which contains the largest remnant of Atlantic Forest in southern Brazil and Iguaçu Falls as one of its main visiting points, is a year-round attraction for thousands of domestic and international tourists. Ring-tailed coatis are generalist, opportunistic carnivores that benefit from human association. These animals are the most abundant carnivores in this park, where they come into close contact with tourists and the resident population around the park. Moreover, as the park is surrounded by human dwellings, free roaming domestic dogs are frequently present, favoring the exchange of pathogens with wild animals. Wild carnivores are known to be infected with several pathogens, from viruses to arthropods, some of them passed on by domestic carnivores. Among the nematodes that infect wild carnivores, those of the Onchocercidae family are of concern due to their zoonotic potential. The objective of this research was to assess the prevalence of filarial nematodes in coatis and dogs in Iguaçu National Park, as well as the potential impact of infection on host health and body condition. To this end, 75 coatis and 50 adult dogs were captured in the aforementioned area. Seven species of filarioids, Dirofilaria immitis, Dirofilaria repens, Acanthocheilonema reconditum, Brugia sp., Mansonella sp. and two undetermined species, confirmed by histochemical tests, were diagnosed in the area. Knott's concentration test in coatis and dogs showed a prevalence of 81.6% and 16.0%, respectively. Seven microfilarial morphotypes were diagnosed in the coatis and two morphotypes were found in the dogs. A specific immunoassay test for Dirofilaria immitis revealed the presence of D. immitis infection in 1.33% of the coatis and 22% of the domestic dogs. The parasitic infection had negligible effects on the body condition of both dog and coati hosts, but an increase was found in eosinophil counts in coatis with filarial infection, as well as decreases in hematocrit and hemoglobin in the infected domestic dogs. These findings represent new locality and host records for all the filarioids diagnosed in the area of this study, with some of the diagnosed parasites, given their zoonotic potential, representing a health risk for park visitors and the local population.

Malaria in Brazil: what happens outside the Amazonian endemic region

Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation's territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation's malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013). The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon) or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex). The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites that seem to be (or to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon.

Notes on the occurrence and habitats of Sabethes purpureus in Salta Province, Argentina

The finding of Sabethes purpureus larvae and pupae in tree holes both in urban and forest environments in San Ramón de la Nueva Orán, Salta Province, Argentina, is reported, together with information on the larval habitat. Tree holes were sampled monthly from January to March or April of 2011, 2012, and 2013 along sidewalks, in public access areas, and in 3 sites within forested areas outside the city, selected along an urban gradient in Orán. Sabathes purpureus was most frequently found in low numbers and with other mosquito species. A higher proportion of tree holes was positive in the urban compared to the forest environment, although there were no significant differences in abundances or densities per hole. To our best knowledge, this paper reports the species for the first time breeding in an urban environment, and extends its geographical distribution from the Atlantic and Paranaense forests to the Southern Andean Yungas in northwestern Argentina.

Yellow fever vaccine-associated adverse events following extensive immunization in Argentina

As a consequence of YF outbreaks that hit Brazil, Argentina, and Paraguay in 2008-2009, a significant demand for YF vaccination was subsequently observed in Argentina, a country where the usual vaccine recommendations are restricted to provinces that border Brazil, Paraguay, and Bolivia. The goal of this paper is to describe the adverse events following immunization (AEFI) against YF in Argentina during the outbreak in the northeastern province of Misiones, which occurred from January 2008 to January 2009. During this time, a total of nine cases were reported, almost two million doses of vaccine were administered, and a total of 165 AEFI were reported from different provinces. Case study analyses were performed using two AEFI classifications. Forty-nine events were classified as related to the YF vaccine (24 serious and 1 fatal case), and 12 events were classified as inconclusive. As the use of the YF 17D vaccine can be a challenge to health systems of countries with different endemicity patterns, a careful clinical and epidemiological evaluation should be performed before its prescription to minimize serious adverse events.

Seasonal variation of the phytoplankton community structure in the São João River, Iguaçu National Park, Brazil

The limnological characteristics and the phytoplankton community of the pelagic region of the São João River, tributary of the Iguaçu River, Iguaçu National Park were analyzed from August 2008 to July 2009. 221 taxa were identified and the Bacillariophyceae class was the most representative. Bacillariophyceae and Chrysophyceae were the dominant classes in density and Bacillariophyceae in biovolume. According to the DCA carried out for phytoplankton density and biovolume, significant differences were identified between the periods, and between the sites and study periods, respectively. The highest richness of species reached 40 taxa in September 2008 at station 1. The Shannon-Wiener diversity indexes and evenness, calculated from the density of phytoplankton, were temporally heterogeneous and spatially similar. In general, the significant temporal variations in the composition of the phytoplankton community were due to variations in limnological conditions, mainly temperature, transparency and nutrients. Spatially the structure was more similar due to the proximity among the stations. Moreover, the similarity of the distribution of communities in lotic environments were due to the unidirectional flow.

Spatial and temporal variation of the phytoplankton community in a section of the Iguaçu River, Paraná, Brazil

The work aimed to show variations in the composition and structure of the phytoplankton community at high water and low water in Iguaçu Falls, Iguaçu River and to examine the influence of these waterfalls and environmental variables on the community. Phytoplankton samples were taken monthly during a year from two sampling stations in the Iguaçu River. A total of 408 taxa were identified, with Bacillariophyceae being the most strongly represented group. A large differentiation in the composition of the phytoplankton was observed between the sampling stations. The total richness and density of the phytoplankton groups was very low in both sample locations, as well as the Shannon diversity index, but the evenness value was generally high. No significant seasonal and spatial difference in the studied features of the phytoplankton community was seen. But, significant seasonal differences were observed when the density and richness of the algae classes were assessed separately. The heterogeneity of the Iguaçu River's characteristics between the sampling sites caused no significant spatial differentiation in the features of the phytoplankton community. However, the seasonal variation of the climatic conditions has significantly influenced the composition and structure of the community in the Iguaçu River.

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.

New records of mosquito species (Diptera: Culicidae) for Santa Catarina and Paraná (Brazil)

We provide eight new mosquito species records for Santa Catarina (Limatus flavisetosus Oliveira Castro 1935, Mansonia flaveola (Coquillett 1906), Ma. titillans (Walker 1848), Psorophora forceps Cerqueira 1939, Sabethes xyphydes Harbach 1994, Toxorhynchites bambusicolus (Lutz & Neiva 1913), Tx. theobaldi (Dyar & Knab 1906) and Wyeomyia lassalli Bonne-Wepster & Bonne 1921) and three for Paraná (Ochlerotatus argyrothorax Bonne-Wepster & Bonne 1920, Uranotaenia pallidoventer Theobald 1903 and Wyeomyia pilicauda Root 1928). Additionally, we list all species in these eight genera recorded previously in the two states. The known distribution and possible epidemiological implications of the new species records are discussed.

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.

Seasonal life cycle of the tropical cricket Eneoptera surinamensis (Orthoptera, Gryllidae, Eneopterinae)

The life cycle and seasonal distribution of a tropical population of Eneoptera surinamensis (De Geer, 1773) were analyzed aiming to verify whether this species life cycle is associated to the wet and dry seasons. The population studied was found at the Seasonal Alluvial Semi-deciduous Forest, Foz de Iguaçu, PR, Brazil (25º27'54.9'' S; 54º34'27.9'' W), which presents mild mesothermal and super humid climate. Field observations were made at 20- to 24-day intervals, with the first observation occurring on April 30th, 2002 and the last on April 25th, 2003. It was verified that the studied species is univoltine and cyclic with regards to the dry and wet seasons, therefore being heterodynamic and surviving the dry season as adult.

Mosquitoes (Diptera: Culicidae) near a reservoir in the Western part of the Brazilian State of Santa Catarina

Anopheline and other mosquitoes (Diptera: Culicidae) in the southern Brazilian State of Santa Catarina have been studied mostly near the Atlantic sea coast and are not well known in other regions of the state. Collections were made near a reservoir in the western portion of the state. At least 26 species were represented in the collections; 10 are recorded for the first time for the state: Coquillettidia venezuelensis, Cq. juxtamansonia, Mansonia wilsoni, Ochlerotatus fluviatilis, Psorophora ciliata, Ps. discrucians, Ps. lanei, Culex bigoti, Sabethes belisarioi and Sa. identicus, and 12 for the first time in the western portion of the state: Anopheles albitarsis, An. intermedius, An. lutzi, An. parvus, An. strodei, Chagasia fajardi, Cx. quinquefasciatus, Limatus durhamii, Sa. aurescens, Sa. melanonymphe, Trichoprosopon pallidiventer and Wyeomyia limai. The possible medical and veterinary significance of the findings is discussed.

Retrospective study of malaria prevalence and Anopheles genus in the area of influence of the Binational Itaipu Reservoir

The importance of hydroelectric dams beside the human interchange in the maintenance of malarious foci and the occurrence of the Anopheles genus on the Binational Itaipu Reservoir were the main points of this retrospective study. Data were collected from existing registrations at National, State and Municipal Health Departments and literature systematic overview, from January 1984 to December 2003. The occurrence of some outbreak of malaria, mainly by Plasmodium vivax, and the prevalence of species of the Anopheles genus different from Anopheles darlingi in the region are discussed. The malaria in the left bank of Paraná River is a focal problem, which must be approached locally through health, educational and social actions to prevent the continuity of outbreaks in the area. Concomitantly, it is necessary to plan and apply effective surveillance measures in the influence area of the Itaipu Reservoir.