Blood-feeding behavior of Anopheles species (Diptera: Culicidae) in the district of Ilha de Santana, state of Amapá, eastern Brazilian Amazon

ABSTRACT The present study aimed identifying the behavioral patterns of Anopheles species as well as to estimate the parity rate and natural infection analysis for Plasmodium species in the district of Ilha de Santana, state of Amapá, Brazil. The samples were obtained in four and 12-hours collections. In the intradomiciliary and peridomiciliary conditions and also in environments with the presence of animals from January/2017 to December/2018. The entomological parameters evaluated were human biting rate (HBR); Indexes of Anthropophily (IA) and Zoophily (IZ); Parity Rate (PR); Natural Infection Rate (NIR); Monthly and annual entomological inoculation rate (EIR). A total of 1,330 Anopheles specimens were collected, distributed in nine species. All captured species showed preference biting in outdoor enviroment. Anopheles darlingi was the most frequent species collected in indoor environment and the most anthropophilic (IA = 0.39) compared with the remaining species captured. It was also the unique species positive for Plasmodium vivax, had the highest anthropophily degree, highest biting activity and HBR in the first hours with a hight rate of parous females. Anopheles nuneztovari s.l. was the most zoophilic species (IZ = 0.65). These findings suggest that A. darlingi is the main malaria vector in the studied area. Anopheles albitarsis s.l. was the second species more anthropophilic (IA = 0.31) and revealed a stable pattern with a biting activity peak after sunset, consequently this species may contribute with malaria transmission in area.

First record of Aedes (Stegomyia) albopictus in the state of Amapá, northern Brazil / Primeiro registro de Aedes (Stegomyia) albopictus no Estado do Amapá, Brasil

We report the first record of Aedes albopictus (Diptera: Culicidae) in the state of Amapá, northern Brazil. Two female specimens were collected from a Shannon trap in the locality of Ilha de Santana, municipality of Santana, Amapá. The occurrence of the species was confirmed with the installation of ten ovitraps. Aedes albopictus is a species of epidemiological importance for the transmission of arboviruses. Amapá was one of two Brazilian states without any record of this species. (AU)

Relatamos o primeiro registro de Aedes albopictus (Diptera: Culicidae) no Estado do Amapá, no norte do Brasil. Dois espécimes foram coletados em uma armadilha de Shannon na localidade de "Ilha de Santana", município de Santana, no Amapá. O registro foi confirmado com a instalação de dez ovitrampas. Aedes albopictus é uma espécie com importância epidemiológica na transmissão de arboviroses. O Amapá era um de dois estados brasileiros sem registro dessa espécie.(AU)

First record of anopheles konderi Galvão & Damasceno (Diptera: Culicidae) carrying eggs of dermatobia hominis (Linnaeus Jr. ) (Diptera: oestridae), from oriximiná municipality, Pará, Brazil

Abstract INTRODUCTION: The muscoid fly Dermatobia hominis causes cutaneous myiases in mammals. Females of this species use a vector to carry their eggs to the host. This note describes Anopheles konderi acting as phoretic vector for D. hominis. METHODS: A female A. konderi carrying D. hominis was collected using light traps in Oriximiná, Pará, Brazil. The A. konderi specimen was identified at morphological and molecular levels. RESULTS: Eight eggs of D. hominis were observed on the Anopheles konderi female. CONCLUSIONS: Anopheles konderi, only the third Anopheles species recorded as a phoretic vector, may be a potential vector of D. hominis.

Composition, abundance and aspects of temporal variation in the distribution of Anopheles species in an area of Eastern Amazonia

Introduction The diverse and complex environmental conditions of the Amazon Basin favor the breeding and development of Anopheles species. This study aimed to describe the composition, abundance and temporal frequency of Anopheles species and to correlate these factors with precipitation, temperature and relative humidity. Methods The study was conducted in the District of Coração, State of Amapá, Brazil. Samples were collected monthly during three consecutive nights, from 6:00 PM to 10:00 PM, from December 2010 to November 2011. In addition, four 12-hour collections (i.e., 6:00 PM to 6:00 AM) were performed during this period. Results A total of 1,230 Anopheles specimens were collected. In the monthly collections, Anopheles darlingi was the predominant species, followed by An. braziliensis and An. albitarsis s.l., whereas An. darlingi, An. peryassui and An. braziliensis were the most frequent species collected in the 12-hour collections. The greatest number of anophelines was collected in September (the dry season). The highest frequency of anophelines was observed for An. darlingi during September, when there were the least rainfalls of the year, along with lower relative humidity and higher temperatures. There was little variation in the abundance of this species in other months, with the exception of slight increases in February, July and August. Conclusions The major malaria vectors, An. darlingi and An. albitarsis s.l. (likely An. marajoara), were the most abundant species collected in the study area. Consequently, prevention and control measures should be taken to prevent malaria outbreaks in the District of Coração. .

Evidence of two lineages of the dengue vector Aedes aegypti in the Brazilian Amazon, based on mitochondrial DNA ND4 gene sequences

Genetic variation was estimated in ten samples populations of Aedes aegypti from the Brazilian Amazon, by using a 380 bp fragment of the mitochocondrial NADH dehydrogenase subunit 4 (ND4) gene. A total of 123 individuals were analyzed, whereby 13 haplotypes were found. Mean genetic diversity was slightly high (h = 0.666 ± 0.029; π = 0.0115 ± 0.0010). Two AMOVA analyses indicated that most of the variation (~70 percent-72 percent) occurred within populations. The variation found among and between populations within the groups disclosed lower, but even so, highly significant values. F ST values were not significant in most of the comparisons, except for the samples from Pacaraima and Rio Branco. The isolation by distance (IBD) model was not significant (r = 0.2880; p = 0.097) when the samples from Pacaraima and Rio Branco were excluded from the analyses, this indicating that genetic distance is not related to geographic distance. This result may be explained either by passive dispersal patterns (via human migrations and commercial exchange) or be due to the recent expansion of this mosquito in the Brazilian Amazon. Phylogenetic relationship analysis showed two genetically distinct groups (lineages) within the Brazilian Amazon, each sharing haplotypes with populations from West Africa and Asia.

Population genetic structure of the major malaria vector Anopheles darlingi (Diptera: Culicidae) from the Brazilian Amazon, using microsatellite markers

The population genetic structure of Anopheles darlingi, the major human malaria vector in the Neotropics, was examined using seven microsatellite loci from nine localities in central and western Amazonian Brazil. High levels of genetic variability were detected (5-25 alleles per locus; H E = 0.519-0.949). There was deviation from Hardy-Weinberg Equilibrium for 59.79 percent of the tests due to heterozygote deficits, while the analysis of linkage disequilibrium was significant for only two of 189 (1.05 percent) tests, most likely caused by null alleles. Genetic differentiation (F ST = 0.001-0.095; Nm = 4.7-363.8) indicates that gene flow is extensive among locations < 152 km apart (with two exceptions) and reduced, but not absent, at a larger geographic scale. Genetic and geographic distances were significantly correlated (R² = 0.893, P < 0.0002), supporting the isolation by distance (IBD) model. The overall estimate of Ne was 202.4 individuals under the linkage disequilibrium model, and 8 under the heterozygote excess model. Analysis of molecular variance showed that nearly all variation (~ 94 percent) was within sample locations. The UPGMA phenogram clustered the samples geographically, with one branch including 5/6 of the state of Amazonas localities and the other branch the Acre, Rondônia, and remaining Amazonas localities. Taken together, these data suggest little genetic structure for An. darlingi from central and western Amazonian Brazil. These findings also imply that the IBD model explains nearly all of the differentiation detected. In practical terms, populations of An. darlingi at distances < 152 km should respond similarly to vector control measures, because of high gene flow.

Isozyme variation in four species of the Simulium perflavum species group (Diptera: Simuliidae) from the Brazilian Amazon

Electrophoretic studies of isozymes were done with four closely related species of the Simulium perflavum species group (Diptera: Simuliidade) in the Brazilian Amazon, using last-instar larvae collected in the field. Ten enzymes were studied, which yielded 11 loci. Diagnostic loci were not found between Simulium maroniense cytotype D and Simulium rorotaense. Simulium maroniense and S. rorotaense differed from Simulium trombetense by two diagnostic loci (Me and Xdh), and Simulium perflavum differed from the other three species by four diagnostic loci (Me, Xdh, Mdh, and Got). The mean number of alleles per locus ranged from 1.30 to 2.30, the percentage of polymorphic loci ranged from 18.2 to 63.6 per cent and the mean heterozygosity values observed ranged from 0.062 to 0.108. Genetic distances among the species ranged from 0.010 to 0.581. The lowest value was obtained between S. maroniense and S. rorotaense, and the highest between S. perflavum and S. trombetense. The genetic relationships among the four S. perflavum group species indicate that they are closely related. The high similarity at the isozyme level, allied to previous studies of morphology and polytene chromosomes, may suggest that the divergence time since the separation of S. maroniense and S. rorotaense is still too recent for diagnostic loci to have evolved

Biologia de anofelinos amazônicos: XII. Ocorrência de espécies de Anopheles, dinâmica da transmissäo e controle da malária na zona urbana de Ariquemes (Rondônia) / Biology of Amazonian anophelines: XII. Species of Anopheles: transmission dynamics and control of malaria in the urban area of Ariquemes (Rondônia, Brazil)

Dados sobre o grau de incidência e distribuiçäo de espécies Anopheles, em Ariquemes (RO), evidenciaram que a diversidade é maior na periferia da cidade e que Anopheles darlingi é registrada em praticamente todas as localidades de coleta. O inquérito entomológico revelou níveis diferentes de penetraçäo da espécie na área urbana, podendo-se constatar que os Setores 1 e 3 säo áreas livres de malária; Setores 2 e 4 mostram riscos na periferia; e a Area Industrial e Setor de Areas Especiais, Conjunto BNH, Setor 5 e Vila Velha constituem áreas de alto risco da malária. Nestes últimos, os índices de mosquitos por homem/hora os mais elevados, observando-se variaçöes no decorrer das amostragens e conforme a localizaçäo da área urbana. Medidas de densidade populacional revelaram mudanças estacionais, sendo os menores valores registrados no período de inverno. A transmissäo da malária é discutida, considerando-se: 1) papel de estrutura física da cidade, na época da fundaçäo, 2) os igarapés que margeam a área urbana e suas relaçöes com o ciclo de desenvolvimento dos anofelinos, 3) os padröes comportamentais da atividade de picar das espécies correlacionados a ambientes naturais e às áreas ecologicamente alteradas, e 4) a importância do manuseio ambiental no controle da malária, para reduçäo da densidade populacional. Para conter o processo migratório do vetor é proposto um cinturäo de proteçäo à cidade, constituído de mata näo densa, incluindo também proteçäo biológica para incentivar a zoofilia dos anofelinos. Os resultados de infecçäo natural, obtidos em áreas de autoctonia da malária, permitem citar A. darlingi como vetor, sendo discutida a possibilidade de que outras espécies estejam envolvidas na transmissäo