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A new sand fly species, Trichophoromyia jariensis n. sp. Cavalcante, Rodrigues, & Galati, from the state of Amapá, Brazil, is described based on both male and female morphology and cytochrome c oxidase subunit I DNA barcodes. The DNA barcoding analysis clearly associated males and females of this new species., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

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., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Saraiva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Aedes aegypti is associated with dengue, Zika, and chikungunya transmission. These arboviruses are responsible for national outbreaks with severe public health implications. Vector control is one of the tools used to prevent mosquito proliferation, and SumiLarv ® 2MR is an alternative commercial product based on pyriproxyfen for larval/pupal control. In this study, the residual effectiveness of SumiLarv ® 2MR in different regions of Brazil was evaluated in simulated field conditions., Methods: We conducted a multicenter study across four Brazilian states-Amapá, Pernambuco, Rio de Janeiro, and São Paulo-given the importance to the country's climatic variances in the north, northeast, and southeast regions and their influence on product efficiency. The populations of Ae. aegypti from each location were held in an insectary. Third-instar larvae (L3) were added every 2 weeks to water containers with SumiLarv ® 2MR discs in 250-, 500- and 1000-l containers in Amapá and Rio de Janeiro, and 100-l containers in Pernambuco and São Paulo, using concentrations of 0.04, 0.08, and 0.16 mg/l., Results: Adult emergence inhibition over 420 days was observed in all tests conducted at a concentration of 0.16 mg/l; inhibition for 308-420 days was observed for 0.08 mg/l, and 224-420 days for 0.04 mg/l., Conclusions: Sumilarv ® 2MR residual activity demonstrated in this study suggests that this new pyriproxyfen formulation is a promising alternative for Aedes control, regardless of climatic variations and ideal concentration, since the SumiLarv ® 2MR showed adult emergence inhibition of over 80% and residual activity greater than 6 months, a period longer than that recommended by the Ministry of Health of Brazil between product re-application in larval breeding sites., (© 2024. The Author(s).)

Insecticide resistance in Aedes aegypti poses a significant threat to disease control. One form of resistance, caused by kdr mutations in the Na V gene, hinders vector control efforts in Brazil. Despite genetic differences typically accumulating among isolated populations, this mosquito can actively and passively disperse through human transportation. Our study investigated the genetic structure and spread of kdr mutations in Ae. aegypti populations across six localities in Amapá State, Brazil, within the Amazonian Forest. Using 12 microsatellite loci and qPCR methods, we assessed genetic structure and identified three common kdr mutations (V410L, V1016I, and F1534C). High prevalence of kdr alleles was observed in all localities, indicating widespread distribution in Amapá State. Microsatellite analysis revealed differentiation among mosquito populations, dividing them into two distinct clusters supported by Bayesian and DAPC analyses. Oiapoque, located along the northern border with French Guiana, exhibited the highest kdr frequencies and genetic differentiation compared to other localities. Our findings suggest genetic structure in Ae. aegypti populations in Amapá State, with some passive gene flow between clusters. The study underscores the need for continuous surveillance of Ae. aegypti populations to monitor the spread of insecticide resistance and inform effective vector control strategies., (© 2023. Springer Nature Limited.)

Background: Most cases of malaria in Brazil are concentrated in the Amazon region. One of the vector control alternatives recommended by the WHO is the long-lasting insecticidal net (LLIN). This tool is used in the nine federal states of the Brazilian Legal Amazon, where LLINs are essential for reducing vector density and disease transmission as they prevent contact between the mosquito and the individual. The objective of this study was to evaluate the residuality and use of LLIN insecticides in different health regions in a city located in the Brazilian Amazon., Methods: A total of 17,027 LLINs were installed in the third, fifth and ninth health regions of the municipality of Porto Velho, Rondonia State, Brazil. The LLINs were of two types: Olyset (permethrin), for around the bed, and Interceptor (alphacypermethrin), for around hammocks. The residuality of 172 LLINs was evaluated using cone bioassays to verify the mortality rate of the mosquito Nyssorhynchus darlingi, over a period of 2 years. Structured questionnaires on the acceptance and use of LLINs were distributed to the participating population (n = 391), covering a total sample of 1147 mosquito nets. The mortality rate was evaluated both in terms of days after LLIN installation and the type of insecticide used. Statistical analyses were based on analysis of variance (ANOVA) and Chi-square and were performed using the SPSS statistical program., Results: For the Ny. darlingi mosquito, Interceptor-type LLINs showed residual efficacy, with mortality rates ≥ 80% during the 2-year study period, as determined by the WHO. In contrast, Olyset-type LLINs were associated with a reduction in mortality rates, with 76% and 45% mortality rates in the last two assessments, which occurred during the last 6 months of the study period. Based on the structured questionnaires, the acceptance rate, i.e. percentage of individuals accepting the permanence of the 1147 LLINs sampled, in the three health regions of Porto Velho was 93.8% (of 1076 LLINs)., Conclusion: The alphacypermethrin-impregnated LLIN was more effective than the LLIN impregnated with permethrin. The results indicate that the correct use of mosquito nets-and consequently the protection of the population-needs to be supported by health promotion actions. These initiatives are considered to be essential for the success of this vector control strategy. New studies that consider the monitoring of the placement of mosquito nets are necessary to provide effective support in the correct use of this methodology., (© 2023. The Author(s).)

Rhodnius amazonicus has been previously reported in the Brazilian states of Amazonas and Pará, as well as in French Guiana. However, this is the first recorded presence of this species in Amapá, which is situated in the northern region of Brazil. The specimen was collected from a house in the rural area of the municipality of Porto Grande. Other triatomines, such as Panstrongylus geniculatus, Rhodnius pictipes, and Eratyrus mucronatus, were also found in the same locality in different houses. These species are vectors of Trypanosoma cruzi, which causes Chagas disease. Therefore, this report may contribute to understanding transmission in the state of Amapá, where new infections and outbreaks of Chagas disease have been recorded., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 Published by Elsevier Ltd.)

Mansonia are aggressive mosquito species that are abundant in aquatic ecosystems where the macrophyte plants occur. These mosquitoes are commonly found across the Amazon/Solimões River basin. However, little is known about the oviposition behavior of these species. In the present study, we registered observations on the oviposition activity of 3 species: Mansonia amazonensis, Ma. humeralis, and Ma. cf. titillans, in 5 species of macrophytes in the vicinities of the Madeira River, Porto Velho, State of Rondônia, Brazil. Overall, 197 egg batches were collected. A greater amount of egg batches was found in Salvinia molesta as compared with other macrophytes sampled. In addition, 2 new oviposition habitats were noted in Ludwigia helmintorrhiza and Limnobium spongia. These findings will be important to understand the reproductive dynamics of these mosquitoes in the Brazilian Amazon basin., (Copyright © 2023 by The American Mosquito Control Association, Inc.)

Background: The vector species in the Amazon River Basin are regionally and locally diverse, which makes it imperative to understand and compare their roles in malaria transmission to help select appropriate methods of intervention and evaluation. The major aim of this study was to measure the vectorial capacity of five Anopheles species in three neighbouring villages, for two Plasmodium parasite species affecting humans., Methods: From 32 consecutive months of sampling in three villages, 1.5-7.0 km apart, on the Matapi River, Amapá State, Brazil, vectorial capacities (C) were estimated as time series for An. darlingi, An. marajoara, An. nuneztovari, An. triannulatus, and An. intermedius. Monthly parity measurements for each vector species were used to estimate daily survivorship and compared to estimates of survivorship from mark-release-recapture experiments. Gonotrophic cycle lengths were estimated through a time-series analysis of parity data, and durations of sporogony at study site temperatures for the two malaria parasite species were estimated from previous literature., Results: The absolute abundances of five vector species were strongly tracked by the spatial variation in C among villages. Temporally, C varied between wet and dry seasons, with An. darlingi, An. marajoara and An. triannulatus exhibiting higher C in the dry season from August to December, and An. nuneztovari its highest C early in the rainy season in January and February. Anopheles intermedius exhibited higher C in the rainy season from April to June than in the dry season. Significant differences in overall survival for each independent variable, and a significant difference in C between wet and dry seasons, among villages, and among vector species for both Plasmodium falciparum and Plasmodium vivax. A generalized linear mixed model (GLMM) analysis by village showed significant effects of vector species on C in only one village, but significant effects of parasite species in all three. Although the GLMM analysis detected no significant parasite x vector species interaction effects on C, effects on C of spline regressions of C dynamics x vector species interactions were significant in all villages., Conclusions: These detailed analyses of entomological and parasitological variables revealed hidden complexities of malaria epidemiology at local scales in neighbouring riverine villages of the Amazon Region., (© 2022. The Author(s).)

Mansonia (Diptera: Culicidae) are known to cause discomfort to the local populations of Amazon. Considering the fact that the effective control of these mosquitoes can only be obtained by understanding their ecology and behavior, entomological monitoring becomes essential. In view of this, mosquitoes of the genus Mansonia were collected by human landing catches (HLC) from 2015 to 2019, in four locations of Porto Velho, Rondônia, Brazil. The collections were performed inside and outside the homes, once in every four months, uninterrupted for 24 hr. Human bite indices/hour was used to analyze the hourly activity of the species for different seasons and environment (indoor and outdoor). Moreover, nonparametric Mann-Whitney tests were conducted to indicate if there were differences between exophagic and endophagic behavior. The seasonality of Mansonia species was also analyzed. Overall, 96,766 specimens were collected over five years of sampling. Mansonia titillans (Walker) was found to be the most abundant species (76.9%). The highest percentage of mosquitoes was collected in February (48.4%), followed by October (39.6%) and June (12.0%). The biting activity of the two most abundant species showed peak host seeking activity/behavior during twilight and night, more perceptible in the outdoor environment (peridomiciliary). In general, seasonality showed a tendency towards a reduction in the abundance of Mansonia in the years after 2015. Our results will be essential in the formulation of effective control methodology for Mansonia in the studied area., (© The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America.)

High abundance of hematophagous mosquitoes of the genus Mansonia Blanchard, 1901 (Diptera: Culicidae) threatens human and domestic animal health and well-being. Knowledge of the biology of nuisance mosquito species is necessary to understand specific ecological and biological factors to enable rapid and effective monitoring measures for sustainable control programs. The establishment and dispersion of Mansonia species are associated with the occurrence of aquatic macrophytes species, which are indispensable for the development of larvae and pupae. To increase knowledge of the host plants for Mansonia immature stages in Porto Velho, Rondonia State, Brazil, specimens of four plant species, which occur across the tributaries of the Madeira River were sampled and inspected for the presence of egg batches, larvae, and pupae. A total of 1,386 larvae and pupae of Mansonia spp. were collected attached to the roots of Eichhornia crassipes (Mart.) Solms (Commelinales: Pontederiaceae), Pistia stratiotes L. (Alismatales: Araceae), and Limnobium laevigatum (Humb. and Bonpl. Ex Willd.) Heine (Alismatales: Hydrocharitaceae). The novel association of Mansonia species with L. laevigatum is presented. Egg batches of Mansonia spp. were found only on Salvinia molesta D.S. Mitch. (Salviniales: Salviniaceae). Possible differences in the roles played by E. crassipes and S. molesta in the reproductive cycle of Mansonia spp. in the surveyed area are discussed. All species of host plants including E. crassipes, P. stratiotes, S. molesta, and L. laevigatum should be considered when planning macrophyte management for the control of Mansonia species., (© The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)