Composition of Anopheles Meigen (Diptera: Culicidae) in a peri-urban area of the Eastern Amazon

Malaria vector mosquitoes belong to the genus Anopheles Meigen. The Amazon has been changing due to economic activities such as mining, logging, agriculture, and urbanization, leading to changes in malaria transmission patterns in this region. Therefore, this study aimed to survey Anopheles species in a peri-urban area of Macapá, state of Amapá, Eastern Amazon, Brazil. Human landing catches (HLC) and Shannon light traps were used to collect Anopheles adults at three points. We screened breeding sites in all accessible water reservoirs within a 2 km radius of each collection point to collect immatures and found two species: Anopheles (Nyssorhynchus) albitarsis s.l. Lynch-Arribalzága (35.7%) and Anopheles (Nyssorhynchus) braziliensis (Chagas) (64.3%). A total of 267 winged specimens of Anopheles were collected: A. (N.) braziliensis (62.9%), Anopheles (Anopheles) mattogrossensis Lutz & Neiva (11.6%), Anopheles (Nyssorhynchus) triannulatus s.l. (Neiva & Pinto) (11.6%), A. (N.) albitarsis s.l. Lynch-Arribálzaga (6.7%), Anopheles (Nyssorhynchus) darlingi Root (5.2%), Anopheles (Anopheles) peryassui Dyar & Knab (1.5%), and Anopheles (Nyssorhynchus) nuneztovari Galbadón (0.4%). Considering that Macapá has autochthonous malaria cases, our findings can contribute to developing public health measures in this municipality, therefore helping to protect its habitants. &nbsp

DNA Barcodes of <i>Mansonia</i> (<i>Mansonia</i>) Blanchard, 1901 (Diptera, Culicidae)

Females of the genus Mansonia feed on the blood of humans, livestock, and other vertebrates to develop their eggs. The females’ biting behavior may cause severe disturbance to blood hosts, with a negative impact on public health and economics. Certain species have been identified as potential or effective disease vectors. The accurate species identification of field-collected specimens is of paramount importance for the success of monitoring and control strategies. Mansonia (Mansonia) morphological species boundaries are blurred by patterns of intraspecific heteromorphism and interspecific isomorphism. DNA barcodes can help to solve taxonomic controversies, especially if combined with other molecular tools. We used cytochrome c oxidase subunit I (COI) gene 5′ end (DNA barcode) sequences to identify 327 field-collected specimens of Mansonia (Mansonia) spp. The sampling encompassed males and females collected from three Brazilian regions and previously assigned to species based on their morphological characteristics. Eleven GenBank and BOLD sequences were added to the DNA barcode analyses. Initial morphospecies assignments were mostly corroborated by the results of five clustering methods based on Kimura two-parameter distance and maximum likelihood phylogeny. Five to eight molecular operational taxonomic units may represent taxonomically unknown species. The first DNA barcode records for Mansonia fonsecai, Mansonia iguassuensis, and Mansonia pseudotitillans are presented

Larvicidal Effect of Hyptis suaveolens (L.) Poit. Essential Oil Nanoemulsion on Culex quinquefasciatus (Diptera: Culicidae)

Mosquitoes can be vectors of pathogens and transmit diseases to both animals and humans. Species of the genus Culex are part of the cycle of neglected diseases, especially Culex&nbsp;quinquefasciatus, which is an anthropophilic vector of lymphatic filariasis. Natural products can be an alternative to synthetic insecticides for vector control; however, the main issue is the poor water availability of some compounds from plant origin. In this context, nanoemulsions are kinetic stable delivery systems of great interest for lipophilic substances. The objective of this study was to investigate the larvicidal activity of the Hyptis suaveolens essential oil nanoemulsion on Cx. quinquefasciatus. The essential oil showed a predominance of monoterpenes with retention time (RT) lower than 15 min. The average size diameter of the emulsions (sorbitan monooleate/polysorbate 20) was &le; 200 nm. The nanoemulsion showed high larvicidal activity in concentrations of 250 and 125 ppm. CL50 values were 102.41 (77.5253&ndash;149.14) ppm and 70.8105 (44.5282&ndash;109.811) ppm after 24 and 48 h, respectively. The mortality rate in the surfactant control was lower than 9%. Scanning micrograph images showed changes in the larvae&rsquo;s integument. This study achieved an active nanoemulsion on Cx. quinquefasciatus through a low-energy-input technique and without using potentially toxic organic solvents. Therefore, it expands the scope of possible applications of H. suaveolens essential oil in the production of high-added-value nanosystems for tropical disease vector control