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Malaria is an important public health problem, caused by Plasmodium parasites which are transmitted by female Anopheles mosquitoes that bite humans to obtain blood. The aim of this work was to identify the blood feeding sources of Anopheles female mosquitoes and calculate their entomological indices in relation to Plasmodium transmission. Mosquitoes were collected in malaria endemic localities of the Bajo Cauca and Pacific regions of Colombia using human landing catch and barrier screens, from 18:00 to 24:00 hr, in 2018-2021. Animal censuses within a radius of ∼250 m were carried out at each sampling site. A total of 2018 Anopheles specimens were collected and the most abundant species were Anopheles (Nys.) darlingi and Anopheles (Nys.) nuneztovari. The highest human biting rate was 77.5 bites per person per night (b/p/n) for An. nuneztovari in Córdoba-Pacific and 17.5 b/p/n for An. darlingi in Villa Grande-Bajo Cauca. Both species were active mainly in indoor unwalled rooms of the houses. Only An. nuneztovari from Córdoba-Pacific was infected with Plasmodium, with an entomological inoculation rate of 91.25 infective bites per year. Detection of blood feeding sources demonstrate that humans were the most common host, however, An. nuneztovari showed a preference for feeding on dogs and An. darlingi on pigs, dogs and Galliformes, rather than humans. These results contribute to entomological surveillance information and provide valuable data that can be used to tailor effective control interventions to minimize human-vector contact in these malaria endemic regions., (Copyright © 2022. Published by Elsevier B.V.)

Nyssorhynchus darlingi (Root) is the dominant malaria vector in the Brazilian Amazon River basin, with additional Anophelinae Grassi species involved in local and regional transmission. Mosquito blood-feeding behavior is an essential component to define the mosquito-human contact rate and shape the transmission cycle of vector-borne diseases. However, there is little information on the host preferences and blood-feeding behavior of Anophelinae vectors in rural Amazonian landscapes. The barrier screen sampling (BSS) method was employed to sample females from 34 peridomestic habitats in 27 rural communities from 11 municipalities in the Brazilian Amazon states of Acre, Amazonas, Pará and Rondônia, from August 2015 to November 2017. Nyssorhynchus darlingi comprised 97.94% of the females collected resting on barrier screens, and DNA sequence comparison detected 9 vertebrate hosts species. The HBI index ranged from 0.03-1.00. Results revealed the plasticity of Ny. darlingi in blood-feeding on a wide range of mainly mammalian hosts. In addition, the identification of blood meal sources using silica-dried females is appropriate for studies of human malaria vectors in remote locations., (Copyright © 2020. Published by Elsevier B.V.)

Anopheles albimanus is a major malaria mosquito vector in Colombia. In the present study, wing variability (size and shape) in An. albimanus populations from Colombian Maracaibo and Chocó bio-geographical eco-regions and the relationship of these phenotypic traits with environmental factors were evaluated. Microsatellite and morphometric data facilitated a comparison of the genetic and phenetic structure of this species. Wing size was influenced by elevation and relative humidity, whereas wing shape was affected by these two variables and also by rainfall, latitude, temperature and eco-region. Significant differences in mean shape between populations and eco-regions were detected, but they were smaller than those at the intra-population level. Correct assignment based on wing shape was low at the population level (<58%) and only slightly higher (>70%) at the eco-regional level, supporting the low population structure inferred from microsatellite data. Wing size was similar among populations with no significant differences between eco-regions. Population relationships in the genetic tree did not agree with those from the morphometric data; however, both datasets consistently reinforced a panmictic population of An. albimanus. Overall, site-specific population differentiation is not strongly supported by wing traits or genotypic data. We hypothesize that the metapopulation structure of An. albimanus throughout these Colombian eco-regions is favoring plasticity in wing traits, a relevant characteristic of species living under variable environmental conditions and colonizing new habitats., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Anopheles punctimacula s.l. is a regional malaria vector in parts of Central America, but its role in transmission is controversial due to its unresolved taxonomic status. Two cryptic species, An. malefactor and An. calderoni, have been previously confused with this taxon, and evidence for further genetic differentiation has been proposed. In the present study we collected and morphologically identified adult female mosquitoes of An. punctimacula s.l. from 10 localities across Panama and one in Costa Rica. DNA sequences from three molecular regions, the three prime end of the mitochondrial cytochrome c oxidase I gene (3' COI), the Barcode region in the five prime end of the COI (5' COI), and the rDNA second internal transcribed spacer (ITS2) were used to test the hypothesis of new molecular lineages within An. punctimacula s.l. Phylogenetic analyses using the 3' COI depicted six highly supported molecular lineages (A-F), none of which was An. malefactor. In contrast, phylogenetic inference with the 5' COI demonstrated paraphyly. Tree topologies based on the combined COI regions and ITS2 sequence data supported the same six lineages as the 3' COI alone. As a whole this evidence suggests that An. punctimacula s.l. comprises two geographically isolated lineages, but it is not clear whether these are true species. The phylogenetic structure of the An. punctimacula cluster as well as that of other unknown lineages (C type I vs C type II; D vs E) appears to be driven by geographic partition, because members of these assemblages did not overlap spatially. We report An. malefactor for the first time in Costa Rica, but our data do not support the presence of An. calderoni in Panama., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Across the Americas and the Caribbean, nearly 561,000 slide-confirmed malaria infections were reported officially in 2008. The nine Amazonian countries accounted for 89% of these infections; Brazil and Peru alone contributed 56% and 7% of them, respectively. Local populations of the relatively neglected parasite Plasmodium vivax, which currently accounts for 77% of the regional malaria burden, are extremely diverse genetically and geographically structured. At a time when malaria elimination is placed on the public health agenda of several endemic countries, it remains unclear why malaria proved so difficult to control in areas of relatively low levels of transmission such as the Amazon Basin. We hypothesize that asymptomatic parasite carriage and massive environmental changes that affect vector abundance and behavior are major contributors to malaria transmission in epidemiologically diverse areas across the Amazon Basin. Here we review available data supporting this hypothesis and discuss their implications for current and future malaria intervention policies in the region. Given that locally generated scientific evidence is urgently required to support malaria control interventions in Amazonia, we briefly describe the aims of our current field-oriented malaria research in rural villages and gold-mining enclaves in Peru and a recently opened agricultural settlement in Brazil., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Anopheles mosquitoes are routinely identified using morphological characters of the female that often lead to misidentification due to interspecies similarity and intraspecies variability. The aim of this work was to evaluate the applicability of a previously developed PCR-RFLP-ITS2 assay for accurate discrimination of anophelines in twelve localities spanning three Colombian malaria epidemiological regions: Atlantic Coast, Pacific Coast, and Uraba-Bajo Cauca-Alto Sinu region. The evaluation of the stability of the PCR-RFLP patterns is required since variability of the ITS2 has been documented and may produce discrepancies in the patterns previously reported. The assay was used to evaluate species assignation of 939 mosquitoes identified by morphology. Strong agreement between the morphological and molecular identification was found for species Anopheles albimanus, Anopheles aquasalis, Anopheles darlingi and Anopheles triannulatus s.l. (p≥0.05, kappa=1). However, disagreement was found for species Anopheles nuneztovari s.l., Anopheles neomaculipalpus, Anopheles apicimacula and Anopheles punctimacula (p≤0.05; kappa ranging from 0.33 to 0.80). The ITS2-PCR-RFLP assay proved valuable for discriminating anopheline species of northern and western Colombia, especially those with overlapping morphology in the Oswaldoi Group., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Malaria is an important public health problem in Colombia. Among the major vectors in Colombia, Anopheles albimanus is recognized for its importance on the Pacific Coast where it is the predominant species; it is also found in the Atlantic Coast, although its vectorial role in this region is not clear. We examined the occurrence of An. albimanus in four localities of the Pacific and three of the Atlantic Coast. Morphological identification of problematic specimens was confirmed by a molecular assay. All identified mosquitoes at these sites, including An. albimanus, were also tested for malaria parasite infection. From 12,189 anophelines collected, 6370 were from the Pacific Coast, and corresponded to 99% An. albimanus, 0.8% Anopheles neivai, and three other species at <0.2%. From the Atlantic Coast we identified 5819 specimens with 61% An. albimanus, 36% Anopheles triannulatus s.l. and five other species at <2%. In both coasts, species present at lower percentages included several incriminated as vectors in neighboring countries. Six Pacific Coast specimens were infected with malaria parasites: four An. albimanus, two with Plasmodium vivax VK247, one with P. vivax VK210 and one with Plasmodium falciparum; two An. neivai with P. falciparum. Our data support the continued predominance of An. albimanus in the Pacific Coast, and demonstrate that this species is the most abundant in the Atlantic Coast as well.