Bioecological Aspects of Species of the Subgenus Mansonia (Mansonia) (Diptera: Culicidae) Prior to the Installation of Hydroelectric Dams on the Madeira River, Rondônia State, Brazil.

The objective of this study was to evaluate ecological aspects of Mansonia species before the construction of hydroelectric plants on the Madeira River, and thus enable the assessment of the impact of these projects on mosquitoes. A total of 199 samplings were carried out between November 2003 and August 2004, using the technique of attraction with protection. Temporal distribution was evaluated from monthly incidence values obtained from the bite index per man/hour. Relative abundance was subsequently calculated to evaluate the spatial distribution of species, according to land use and municipal districts; furthermore, the pattern of hematophagous activity was evaluated from 12-h and 4-h samplings. The data were analyzed according to the negative binomial distribution and generalized linear models to estimate the influence of environmental factors on the presence and abundance of Mansonia. A total of 1479 specimens were collected, distributed among four species-Mansonia titillans (87%), Mansonia humeralis (6.3%), Mansonia amazonensis (6%), and Mansonia indubitans (0.5%), and spatial distribution analysis showed Ma. titillans to be dominant. Hematophagous activity had peaks between 6:00 p.m. and 8:00 p.m. and species incidence was higher during the rainy season and in areas where domestic animals are raised. Therefore, the region studied presented characteristics favorable to the reproduction of Mansonia even before the construction of the hydroelectric plants and after construction, these conditions were enhanced, due to the increase in the availability of breeding sites for immatures and blood sources for females, as a consequence of changes in the environment.

DNA barcoding suggests new species for the Mansonia subgenus (Mansonia, Mansoniini, Culicidae, Diptera) in the area surrounding the Jirau hydroelectric dam, Porto Velho municipality, Rondônia state, Brazil.

Previous studies have linked the construction of hydroelectric dams with increases in the density of mosquitoes, especially Mansonia. In Brazil, Mansonia mosquitoes are still poorly studied at the taxonomic, biological, ecological and epidemiological levels, and nothing is known about the genetic diversity and the cryptic speciation of the group. The current study analyzed the molecular taxonomy of Mansonia species captured in the area surrounding the Jirau hydroelectric dam, Rondônia state, Brazil. Samples were collected from fifteen locations between 2018 and 2019. Genomic DNA of the specimens was extracted, and the DNA barcode region of the Cytochrome Oxidase, subunit I gene was amplified with PCR and both DNA strands were sequenced. The dataset was analyzed using MEGA, Mr. Bayes and DnaSP software. The results provided COI sequences for 100 specimens collected in the area surrounding from Jirau hydroelectric dam. These belonged to five species of the Mansonia subgenus, identified morphologically as Mansonia humeralis, Mansonia amazonensis, Mansonia titillans, Mansonia dyari and Mansonia indubitans. Findings showed that the COI gene is an effective and accessible DNA barcode that provides a high-resolution tool for delimiting species within the subgenus Mansonia, with the tree construction (Bayesian Inference) well supported and non-overlapping intraspecific and interspecific (K2-P) genetic distance values. These findings also indicate the occurrence of cryptic speciation within M. dyari and near of M. titillans. This is the first study to apply molecular tools to the taxonomy of Mansonia species from Brazil.

Diversity and spatio-temporal variation of Anopheles (Diptera: Culicidae) before and after the construction of the Jirau hydroelectric plant, state of Rondônia, Brazil

ABSTRACT The objective of this study was to evaluate the effect of the construction of the Jirau hydroelectric plant on the anopheline species, in Porto Velho, Rondônia, Brazil. For this, sampling was carried out in 23 locations in the pre (2004) and 23 after construction (2018) phases in the hydroelectric dam's coverage area, performed by human landing catch between 6:00 pm and 10:00 pm. We found 14 anopheline species. In the pre-construction phase, An. darlingi (73%) was the most abundant and after construction An. braziliensis (31.5%) was the most abundant. The T test indicated that there were no differences in the indexes - diversity (H '), richness (Sjack 1), equitability (J') and dominance (d) of anophelines species - evaluated between the phases (p > 0.05). The spatio-temporal distribution of An. darlingi proved to be wide, with the highest density values observed in March ( x ¯w = 27.1) in the pre-construction phase and in the months of May ( x ¯w = 4) and July ( x ¯w = 3.1), post-construction. Differences in hematophagic activity peaks were observed between species and between phases. According to the data obtained in this study, the construction of the hydroelectric plant had little influence on the composition of anopheline species, however changes were observed in the spatio-temporal distribution of the An. darlingi and in the pattern of hematophagic activity of the species, which directly influenced the dynamics of malaria in the region.

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.

Larvicidal effects of endophytic and basidiomycete fungus extracts on Aedes and Anopheles larvae (Diptera, Culicidae).

INTRODUCTION: In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. METHODS: The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. RESULTS: The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. CONCLUSIONS: These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts.

Larvicidal effects of endophytic and basidiomycete fungus extracts on Aedes and Anopheles larvae (Diptera, Culicidae)

Introduction In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. Methods The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. Results The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. Conclusions These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts. .