Background Continuous vector surveillance and sustainable interventions are mandatory in order to prevent anopheline proliferation (or spread to new areas) and interrupt malaria transmission. Anopheline abundance and richness were evaluated in urban and peri-urban malaria foci at a medium-sized city in the Brazilian Amazon, comparing the protected human landing catch technique (PHLC) and alternative sampling methods over different seasonal periods. Additional information was assessed for female feeding behaviour and faunal composition. Methods Anophelines were sampled bimonthly in four urban and peri-urban sites in the city of Porto Velho, state of Rondônia, Brazil. The average number of captured mosquitoes was compared between an PHLC (gold standard), a tent trap (Gazetrap), and a barrier screen by means of generalized linear mixed models (GLMM), which also included season and environment (peri-urban/urban) as predictors. Results Overall, 2962 Anopheles individuals belonging to 12 species and one complex were caught; Anopheles darlingi represented 86% of the individuals. More mosquitoes were captured in the peri-urban setting, and the urban setting was more diverse. The model estimates that significantly more anophelines were collected by PHLC than by the Screen method, and Gazetrap captured fewer individuals. However, the Screen technique yielded more blood-engorged females. The peak hours of biting activity were from 6 to 7 p.m. in urban areas and from 7 to 8 p.m. in peri-urban areas. Conclusions Although peri-urban settings presented a greater abundance of anophelines, Shannon and Simpson diversities were higher in urban sites. Each technique proved to be useful, depending on the purpose: PHLC was more effective in capturing the highest anopheline densities, Gazetrap caught the greatest number of species, and the barrier screen technique captured more engorged individuals. There was no seasonal effect on Anopheles assemblage structure; however, a more diverse fauna was caught in the transitional season. Biting activity was more intense from 6 to 8 p.m., with a predominance of An. darlingi.

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Culex spp. mosquitoes have idiosyncratic characteristics and its low variability makes difficult their identification. The aim of our study was to analyze the 5' region of the cytochrome oxidase subunit I gene (coI) for the taxonomic identification of Culex species which were previously morphotyped and diagnosed in Culex and Melanoconion subgenera at the field conditions. Ten specimen sequences were analyzed by the Automatic Barcode Gap Discovery (ABGD). All sequences showed 94-99% identity when compared to other Culex species sequences available from GenBank. Five initial partitions supported 80-88 species groups. Among them, eight sets contained the specimens of the present study. Of the 10 mosquito sequences, five did not form any consistent cluster, and the remaining showed some consistency in the taxonomic diagnosis at the field conditions. Our results suggest that some coI gene sequences of specimens may belong to species of the subgenus Melanoconion, whose 5' coI sequence is unknown or unpublished in GenBank. Palavras-chave: ABGD, coI gene, HP trap, Neighbor-Joining method, Taxonomic Diagnosis. ResumoOs mosquitos Culex spp. apresentam características idiossincráticas e sua baixa variabilidade dificulta sua identificação. O objetivo do nosso estudo foi analisar a região 5 'do gene da subunidade I do citocromo oxidase (coI) para a identificação taxonômica de espécies de Culex que foram previamente diagnosticadas em subgêneros Culex e Melanoconion em condições de campo. Dez sequências de espécimes foram analisadas pelo Automatic Barcode Gap Discovery (ABGD). Todas as sequências apresentaram 94-99% de identidade quando comparadas com outras sequências de espécies de Culex disponíveis no GenBank. Cinco partições iniciais suportaram 80-88 grupos de espécies. Entre eles, oito conjuntos continham os espécimes do presente estudo. Das 10 sequências de mosquitos, cinco não formaram nenhum cluster consistente, e as demais apresentaram alguma consistência no diagnóstico taxonômico nas condições de campo. Nossos resultados sugerem que algumas sequências do gene coI de espécimes podem pertencer a espécies do subgênero Melanoconion, cuja sequência 5' coI é desconhecida ou inédita no GenBank.