Trends of Mansonia (Diptera, Culicidae, Mansoniini) in Porto Velho: Seasonal patterns and meteorological influences.

Entomological research is vital for shaping strategies to control mosquito vectors. Its significance also reaches into environmental management, aiming to prevent inconveniences caused by non-vector mosquitoes like the Mansonia Blanchard, 1901 mosquito. In this study, we carried out a five-year (2019-2023) monitoring of these mosquitoes at ten sites in Porto Velho, Rondônia, using SkeeterVac SV3100 automatic traps positioned between the two hydroelectric complexes on the Madeira River. Throughout this period, we sampled 153,125 mosquitoes, of which the Mansonia genus accounted for 54% of the total, indicating its prevalence in the region. ARIMA analysis revealed seasonal patterns of Mansonia spp., highlighting periods of peak density. Notably, a significant decreasing trend in local abundance was observed from July 2021 (25th epidemiological week) until the end of the study. Wind speed was observed to be the most relevant meteorological factor influencing the abundance of Mansonia spp. especially in the Joana D'Arc settlement, although additional investigation is needed to comprehensively analyze other local events and gain a deeper understanding of the ecological patterns of this genus in the Amazon region.

Change in the faunal composition of mosquitoes (Diptera: Culicidae) along a heterogeneous landscape gradient in the Brazilian Amazon.

This study aimed to evaluate the influence of different anthropic landscape profiles on the diversity and distribution of mosquito species in a rural settlement of the Brazilian Amazon. Eight field collections were conducted at 18 sampling points interspersed throughout 2020-2021. Plastic containers, bamboo internodes, and tires were used as traps to capture immature mosquitoes in three distinct habitats: forest, forest edge, and peridomicile. A total of 15,547 individuals, distributed in 26 species of culicids, were collected. The most abundant species were Culex urichii (8,376 specimens), Culex (Melanoconion) (2,473 specimens), and Aedes albopictus (1,252 specimens). Forest habitat showed the highest abundance, and forest edge showed the highest species richness. Different types of environments influenced both the abundance and richness of mosquitoes. The species composition was also significantly different between the analyzed sites, mainly between forest and peridomicile environments. The change in species dominance could largely explain this change in mosquito community composition. Haemagogus janthinomys, an important sylvatic arbovirus vector, was found in peridomicile habitats and Ae. albopictus, a vector associated with human environments, was found in forest habitats, thus providing evidence of species spillover. Our results indicated that landscape changes affect mosquito communities, influencing their richness and abundance. These changes may have implications for future arboviral outbreaks in this rural settlement due to the possible establishment of sylvatic vector species in anthropic environments.

Exploring deeper genetic structures: Aedes aegypti in Brazil.

Aedes aegypti, being the principal vector of dengue (DENV1 to 4), chikungunya and Zika viruses, is considered as one of the most important mosquito vectors. In Brazil, despite regular vector control programs, Ae. aegypti still persists with high urban density in all the states. This study aimed to estimate the intra and inter population genetic diversity and genetic structure among 15 Brazilian populations of Ae. aegypti based on 12 microsatellite loci. A total of 510 specimens were analyzed comprising eight locations from northern (Itacoatiara, Manaus, Novo Airão, Boa Vista, Rio Branco, Porto Velho, Guajará-Mirim and Macapá), three from southeastern (Araçatuba, São José de Rio Preto and Taubaté), one from southern (Foz do Iguaçu), one from central west (Cuiabá) and two from northeastern (Campina Grande and Teresina) regions of Brazil. Genetic distances (pairwise values of FST and Nm) and the analysis of molecular variance (AMOVA) were statistically significant, independent of geographic distances among the sites analyzed, indicating that them are under a complex dynamic process that influence the levels of gene flow within and among regions of the country. Bayesian analysis in STRUCTURE revealed the existence of two major genetic clusters, as well as there was genetic substructure within them; these results were confirmed by AMOVA, BAPS and DAPC analyses. This differentiation is the cumulative result of several factors combined as events of multiple introduction, passive dispersal, environmental and climatic conditions, use of insecticides, cycles of extinction and re-colonization followed by microevolutionary processes throughout the country. Isolation by distance also contributed to this differentiation, especially among geographically closer localities. These genetic differences may affect its vector competence to transmit dengue, chikungunya, Zika and the response to vector control programs.

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 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)