To relate stability of malaria transmission to biologic characteristics of vector mosquitoes throughout the world, we derived an index representing the contribution of regionally dominant vector mosquitoes to the force of transmission. This construct incorporated published estimates describing the proportion of blood meals taken from human hosts, daily survival of the vector, and duration of the transmission season and of extrinsic incubation. The result of the calculation was displayed globally on a 0.5° grid. We found that these biologic characteristics of diverse vector mosquitoes interact with climate to explain much of the regional variation in the intensity of transmission. Due to the superior capacity of many tropical mosquitoes as vectors of malaria, particularly those in sub-Saharan Africa, antimalaria interventions conducted in the tropics face greater challenges than were faced by formerly endemic nations in more temperate climes.

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A global index representing the stability of malaria transmission

The internal classification of genus Anopheles is updated to reflect taxonomic actions published since the classification was last reviewed in 1994. Both formal and informal taxa are included. The classification is intended to aid researchers and students who are interested in analysing species relationships, making group comparisons and testing phylogenetic hypotheses. The genus includes 444 formally named and 40 provisionally designated extant species divided between six subgenera: Anopheles, Cellia, Kerteszia, Lophopodomyia, Nyssorhynchus and Stethomyia. Subgenera Anopheles, Cellia and Nyssorhynchus are subdivided hierarchically into nested informal groups of morphologically similar species that are believed to represent monophyletic lineages based on morphological similarity. Changes to the classification include additional species, eliminated species and changes to the hierarchical organization and composition of supraspecific groups, some as a result of molecular studies.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0007485304000562

The classification of genus Anopheles (Diptera: Culicidae): a working hypothesis of phylogenetic relationships

Background: An increasing knowledge of the global risk of malaria shows that the nations of the Americas have the lowest levels of Plasmodium falciparum and P. vivax endemicity worldwide, sustained, in part, by substantive integrated vector control. To help maintain and better target these efforts, knowledge of the contemporary distribution of each of the dominant vector species (DVS) of human malaria is needed, alongside a comprehensive understanding of the ecology and behaviour of each species. Results: A database of contemporary occurrence data for 41 of the DVS of human malaria was compiled from intensive searches of the formal and informal literature. The results for the nine DVS of the Americas are described in detail here. Nearly 6000 occurrence records were gathered from 25 countries in the region and were complemented by a synthesis of published expert opinion range maps, refined further by a technical advisory group of medical entomologists. A suite of environmental and climate variables of suspected relevance to anopheline ecology were also compiled from open access sources. These three sets of data were then combined to produce predictive species range maps using the Boosted Regression Tree method. The predicted geographic extent for each of the following species (or species complex*) are provided: Anopheles (Nyssorhynchus) albimanus Wiedemann, 1820, An .( Nys.) albitarsis*, An .( Nys.) aquasalis Curry, 1932, An .( Nys.) darlingi Root, 1926, An .( Anopheles) freeborni Aitken, 1939, An .( Nys.) marajoara Galvao & Damasceno, 1942, An .( Nys.) nuneztovari*, An .( Ano.) pseudopunctipennis* and An .( Ano.) quadrimaculatus Say, 1824. A bionomics review summarising ecology and behaviour relevant to the control of each of these species was also compiled. Conclusions: The distribution maps and bionomics review should both be considered as a starting point in an ongoing process of (i) describing the distributions of these DVS (since the opportunistic sample of occurrence data assembled can be substantially improved) and (ii) documenting their contemporary bionomics (since intervention and control pressures can act to modify behavioural traits). This is the first in a series of three articles describing the distribution of the 41 global DVS worldwide. The remaining two publications will describe those vectors found in (i) Africa, Europe and the Middle East and (ii) in Asia. All geographic distribution maps are being made available in the public domain according to the open access principles of the Malaria Atlas Project.

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The dominant Anopheles vectors of human malaria in the Americas: Occurrence data, distribution maps and bionomic précis

A short fragment of mt DNA from the cytochrome c oxidase 1 (CO1) region was used to provide the first CO1 barcodes for 37 species of Canadian mosquitoes (Diptera: Culicidae) from the provinces Ontario and New Brunswick. Sequence variation was analysed in a 617-bp fragment from the 5' end of the CO1 region. Sequences of each mosquito species formed barcode clusters with tight cohesion that were usually clearly distinct from those of allied species. CO1 sequence divergences were, on average, nearly 20 times higher for congeneric species than for members of a species; divergences between congeneric species averaged 10.4% (range 0.2-17.2%), whereas those for conspecific individuals averaged 0.5% (range 0.0-3.9%).

Identifying Canadian mosquito species through DNA barcodes

The taxonomy, classification and phylogeny of family Culicidae are reviewed The application of explicit methods of phylogenetic analysis has revealed weaknesses in the traditional classification of mosquitoes, but little progress has been made to achieve a robust, stable classification that reflects evolutionary relationships The current phenetic classification is discussed in view of phylogeny reconstructions based on cladistic analyses of morphological and molecular data It is concluded that the generic and suprageneric relationships and the validity and monophyly of the generic and subgeneric groupings of Culicidae are in need of extensive reappraisal If the classification is to reflect evolutionary history, changes to the nomenclature of mosquitoes are inevitable There is strong morphological and molecular evidence that subfamily Anophelinae and tribes Aedini, Culicini and Sabethini of subfamily Culicinae are monophyletic, but the other taxonomic groupings are not demonstrably monophyletic or have not been subjected to phylogenetic analyses

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The Culicidae (Diptera): a review of taxonomy, classification and phylogeny*

A summary of the problems related to the systematics of primary and secondary Brazilian anophelines vectors of malaria is presented.

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Anopheline Species Complexes in Brazil. Current Knowledge of Those Related to Malaria Transmission

Species identification of anopheline mosquitoes (Diptera: Culicidae) can be problematic because many of them belong to complexes of morphologically similar species, often with contrasted ecology, behaviour and vectorial importance The application of DNA-based diagnostics has proved to be useful for distinguishing between such species We determined ribosomal DNA sequences of the second internal transcribed spacer (ITS2) from samples of 16 species of Anopheles captured in the Amazon Basin, Brazil Length of the ITS2 varied from 323 to 410 base pairs, with GC content ranging from 507% to 665% and sequence identity from 25% to 99% between species Maximum-likelihood paup analysis separated two distinct groups of species conforming with the recognized subgenera Anopheles (represented by eiseni, mattogrossensis, mediopunctatus and peryassui) and Nyssorhynchus (represented by 12 spp) For the latter group, the neighbour-joining tree generated from rDNA sequence ITS2 relationships is compatible with the morphological taxonomic key established for these Amazonian species: albitarsis, aquasalis, benarrochi, braziliensis, darlingi, deaneorum, dunhami, evansae, nuneztovari, oswaldoi, rangeli and triannulatus These ITS2 sequence data proved to be a useful tool for species identification and, potentially, to solve taxonomic problems

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Amazonian malaria vector anopheline relationships interpreted from ITS2 rDNA sequences.

Sequence divergence in the second internal transcribed spacer (ITS2) of ribosomal DNA was examined for female specimens of Anopheles oswaldoi Peryassu from 7 localities in South America. The lengths of ITS2 for all mosquitoes ranged from 348 to 356 nucleotides. After alignment of these sequences, similarity ranged from 87 to 100%. Divergence was within the range of interspecific differences for members of anopheline species complexes. Therefore, specimens were placed into 4 groups that may correspond to at least 4 cryptic species. One is probably related to An. oswaldoi sensu stricto and another to Anopheles konderi Galvao & Damasceno. The other 2 groups may correspond to species for which morphological identification remains to be clarified. These data provide evidence that An. oswaldoi comprise a complex of cryptic species and that DNA identification may help to resolve the taxonomic questions related to this group.

Sequence analysis of the second internal transcribed spacer of ribosomal DNA in Anopheles oswaldoi (Diptera: Culicidae).

We compared the susceptibility of Anopheles oswaldoi and An. konderi to infection by Plasmodium vivax based on the proportion of mosquitoes presenting oocysts and sporozoites. Anophelines were captured in the State of Acre and Rondonia, Brazilian Amazon, and used to obtain F1 progenies. After emergence of adults, male genitalia of mosquitoes of each family were dissected in order to identify them as either An. oswaldoi or An. konderi . F1 progenies of field-captured An. oswaldoi, An. konderi and An. darlingi (used as control) were fed simultaneously on P. vivax -infected blood. Mosquitoes were dissected on day 10–12 after feeding and examined for the presence of oocysts and sporozoites. Both An. oswaldoi and An. konderi developed oocysts in the midguts, however, the percentage of oocyst-positive mosquitoes for An. oswaldoi (13·8%) was higher than for An. konderi (3·3%), and only An. oswaldoi developed salivary infection with sporozoites (6·9% of positivity). Infection rates in An. darlingi ranged from 22·5% to 30·0% for both oocysts and sporozoites. These results indicate that An. oswaldoi can transmit P. vivax and suggest that it is more susceptible than An. konderi . Although An. oswaldoi is an exophilic and zoophilic species, it may be involved in malaria transmission as possibly occurred in the State of Acre.

Comparative susceptibility of two members of the Anopheles oswaldoi complex, An. oswaldoi and An. konderi, to infection by Plasmodium vivax.

e um mosquito ora encarado como antropofilico, oracomo zoofilico ou ecletico. Realizou-se estudo em Guapimirim, Estado doRio de Janeiro, de maio a novembro de 1992, com o intuito de se verificar afonte alimentar preferida desse anofelino atraves de teste imunologico de pre-cipitina. De 1.366 femeas capturadas em abrigos naturais, 725 estavam ingur-gitadas. O conteudo digestivo de apenas 473 delas reagiu no teste de preci-pitina, sendo que em 75,3% dos casos foi identificada apenas uma fonte ali-mentar. Mais da metade dessas femeas havia se alimentado em boi (52,2%),enquanto poucas tinham sugado homem (1,1%). Por outro lado, 24,7% dosespecimes haviam se alimentado em mais de uma fonte sanguinea, principal-mente boi e cavalo. Conclui-se que

Determinação das fontes alimentares de Anopheles aquasalis (Diptera: Culicidae) no Estado do Rio de Janeiro, Brasil, pelo teste de precipitina* Blood-meal sources of Anopheles aquasalis (Diptera: Culicidae) in a South-eastern State of Brazil

Carmen Flores-Mendoza

Papers

Anopheline Species Complexes in Brazil. Current Knowledge of Those Related to Malaria Transmission

Amazonian malaria vector anopheline relationships interpreted from ITS2 rDNA sequences.

Sequence analysis of the second internal transcribed spacer of ribosomal DNA in Anopheles oswaldoi (Diptera: Culicidae).

Comparative susceptibility of two members of the Anopheles oswaldoi complex, An. oswaldoi and An. konderi, to infection by Plasmodium vivax.

Determinação das fontes alimentares de Anopheles aquasalis (Diptera: Culicidae) no Estado do Rio de Janeiro, Brasil, pelo teste de precipitina* Blood-meal sources of Anopheles aquasalis (Diptera: Culicidae) in a South-eastern State of Brazil