Global Distribution of Aedes aegypti and Aedes albopictus in a Climate Change Scenario of Regional Rivalry.

Arboviral mosquito vectors are key targets for the surveillance and control of vector-borne diseases worldwide. In recent years, changes to the global distributions of these species have been a major research focus, aimed at predicting outbreaks of arboviral diseases. In this study, we analyzed a global scenario of climate change under regional rivalry to predict changes to these species' distributions over the next century. Using occurrence data from VectorMap and environmental variables (temperature and precipitation) from WorldClim v. 2.1, we first built fundamental niche models for both species with the boosted regression tree modelling approach. A scenario of climate change on their fundamental niche was then analyzed. The shared socioeconomic pathway scenario 3 (regional rivalry) and the global climate model Geophysical Fluid Dynamics Laboratory Earth System Model v. 4.1 (GFDL-ESM4.1; gfdl.noaa.gov) were utilized for all analyses, in the following time periods: 2021-2040, 2041-2060, 2061-2080, and 2081-2100. Outcomes from these analyses showed that future climate change will affect Ae. aegypti and Ae. albopictus distributions in different ways across the globe. The Northern Hemisphere will have extended Ae. aegypti and Ae. albopictus distributions in future climate change scenarios, whereas the Southern Hemisphere will have the opposite outcomes. Europe will become more suitable for both species and their related vector-borne diseases. Loss of suitability in the Brazilian Amazon region further indicated that this tropical rainforest biome will have lower levels of precipitation to support these species in the future. Our models provide possible future scenarios to help identify locations for resource allocation and surveillance efforts before a significant threat to human health emerges.

Ticks (Acari: Ixodidae) and Associated Pathoge Collected From Domestic Animals and Vegetation in Stann Creek District, Southeastern Belize, Central America.

Data on the prevalence and distribution of ticks and tick-borne diseases in Belize are lacking. Ticks (n = 564) collected from dogs, horses, and vegetation in two villages in Stann Creek District in southeastern Belize in 2018, were molecularly identified and screened for tick-borne nonviral human pathogens. The identity of 417 ticks was molecularly confirmed by DNA barcoding as Rhipicephalus sanguineus (Latreille) (66.43%), Amblyomma ovale Koch (15.59%), Dermacentor nitens Neumann (11.51%), Amblyomma sp. ADB0528 (3.6%), and the remainder being small records (2.87%) of Amblyomma coelebs Neumann, Amblyomma imitator Kohls, Amblyomma tapirellum Dunn, Amblyomma auricularium Conil, and Amblyomma maculatum Koch. Individual tick extracts were screened for the presence of Rickettsia spp., Babesia spp., Babesia microti, Borrelia spp., Ehrlichia spp., and Anaplasma spp. using available conventional polymerase chain reaction (PCR) assays. Rickettsia parkeri strain Atlantic Rainforest was identified in five specimens of A. ovale, and one other unidentified tick, all collected from dogs. Another unidentified tick-also collected from a dog-tested positive for an undefined but previously detected Ehrlichia sp. With the exception of D. nitens, all eight other tick species identified in this study were collected on dogs, suggesting that dogs could be usefully employed as sentinel animals for tick surveillance in Belize.

Phylogenetic analysis of the Neotropical Albitarsis Complex based on mitogenome data.

BACKGROUND: Some of the most important malaria vectors in South America belong to the Albitarsis Complex (Culicidae; Anophelinae; Anopheles). Understanding the origin, nature, and geographical distribution of species diversity in this important complex has important implications for vector incrimination, control, and management, and for modelling future responses to climate change, deforestation, and human population expansion. This study attempts to further explore species diversity and evolutionary history in the Albitarsis Complex by undertaking a characterization and phylogenetic analysis of the mitogenome of all 10 putative taxa in the Albitarsis Complex. METHODS: Mitogenome assembly and annotation allowed for feature comparison among Albitarsis Complex and Anopheles species. Selection analysis was conducted across all 13 protein-coding genes. Maximum likelihood and Bayesian inference methods were used to construct gene and species trees, respectively. Bayesian methods were also used to jointly estimate species delimitation and species trees. RESULTS: Gene composition and order were conserved across species within the complex. Unique signatures of positive selection were detected in two species-Anopheles janconnae and An. albitarsis G-which may have played a role in the recent and rapid diversification of the complex. The COI gene phylogeny does not fully recover the mitogenome phylogeny, and a multispecies coalescent-based phylogeny shows that considerable uncertainty exists through much of the mitogenome species tree. The origin of divergence in the complex dates to the Pliocene/Pleistocene boundary, and divergence within the distinct northern South American clade is estimated at approximately 1 million years ago. Neither the phylogenetic trees nor the delimitation approach rejected the 10-species hypothesis, although the analyses could not exclude the possibility that four putative species with scant a priori support (An. albitarsis G, An. albitarsis H, An. albitarsis I, and An. albitarsis J), represent population-level, rather than species-level, splits. CONCLUSION: The lack of resolution in much of the species tree and the limitations of the delimitation analysis warrant future studies on the complex using genome-wide data and the inclusion of additional specimens, particularly from two putative species, An. albitarsis I and An. albitarsis J.

Exploring malaria vector diversity on the Amazon Frontier.

BACKGROUND: Deforestation in the Amazon and the social vulnerability of its settler communities has been associated with increased malaria incidence. The feeding biology of the most important malaria vectors in the region, notably Nyssorhynchus darlingi, compounds efforts to control vectors and reduce transmission of what has become known as "Frontier Malaria". Exploring Anophelinae mosquito diversity is fundamental to understanding the species responsible for transmission and developing appropriate management and intervention strategies for malaria control in the Amazon River basin. METHODS: This study describes Anophelinae mosquito diversity from settler communities affected by Frontier Malaria in the states of Acre, Amazonas and Rondônia by analysing COI gene data using cluster and tree-based species delimitation approaches. RESULTS: In total, 270 specimens from collection sites were sequenced and these were combined with 151 reference (GenBank) sequences in the analysis to assist in species identification. Conservative estimates found that the number of species collected at these sites was between 23 (mPTP partition) and 27 (strict ABGD partition) species, up to 13 of which appeared to be new. Nyssorhynchus triannulatus and Nyssorhynchus braziliensis displayed exceptional levels of intraspecific genetic diversity but there was little to no support for putative species complex status. CONCLUSIONS: This study demonstrates that Anophelinae mosquito diversity continues to be underestimated in poorly sampled areas where frontier malaria is a major public health concern. The findings will help shape future studies of vector incrimination and transmission dynamics in these areas and support efforts to develop more effective vector control and transmission reduction strategies in settler communities in the Amazon River basin.

Phylogenetic analysis and DNA-based species confirmation in Anopheles (Nyssorhynchus).

Specimens of neotropical Anopheles (Nyssorhynchus) were collected and identified morphologically. We amplified three genes for phylogenetic analysis-the single copy nuclear white and CAD genes, and the COI barcode region. Since we had multiple specimens for most species we were able to test how well the single or combined genes were able to corroborate morphologically defined species by placing the species into exclusive groups. We found that single genes, including the COI barcode region, were poor at confirming species, but that the three genes combined were able to do so much better. This has implications for species identification, species delimitation, and species discovery, and we caution that single genes are not enough. Higher level groupings were partially resolved with some well-supported groupings, whereas others were found to be either polyphyletic or paraphyletic. There were examples of known groups, such as the Myzorhynchella Section, which were poorly supported with single genes but were well supported with combined genes. From this we can infer that more sequence data will be needed in order to show more higher-level groupings with good support. We got unambiguously good support (0.94-1.0 Bayesian posterior probability) from all DNA-based analyses for a grouping of An. dunhami with An. nuneztovari and An. goeldii, and because of this and because of morphological similarities we propose that An. dunhami be included in the Nuneztovari Complex. We obtained phylogenetic corroboration for new species which had been recognised by morphological differences; these will need to be formally described and named.

Mosquito (Diptera: Culicidae) assemblages associated with Nidularium and Vriesea bromeliads in Serra do Mar, Atlantic Forest, Brazil.

BACKGROUND: The most substantial and best preserved area of Atlantic Forest is within the biogeographical sub-region of Serra do Mar. The topographic complexity of the region creates a diverse array of microclimates, which can affect species distribution and diversity inside the forest. Given that Atlantic Forest includes highly heterogeneous environments, a diverse and medically important Culicidae assemblage, and possible species co-occurrence, we evaluated mosquito assemblages from bromeliad phytotelmata in Serra do Mar (southeastern Brazil). METHODS: Larvae and pupae were collected monthly from Nidularium and Vriesea bromeliads between July 2008 and June 2009. Collection sites were divided into landscape categories (lowland, hillslope and hilltop) based on elevation and slope. Correlations between bromeliad mosquito assemblage and environmental variables were assessed using multivariate redundancy analysis. Differences in species diversity between bromeliads within each category of elevation were explored using the Renyi diversity index. Univariate binary logistic regression analyses were used to assess species co-occurrence. RESULTS: A total of 2,024 mosquitoes belonging to 22 species were collected. Landscape categories (pseudo-F value = 1.89, p = 0.04), bromeliad water volume (pseudo-F = 2.99, p = 0.03) and bromeliad fullness (Pseudo-F = 4.47, p < 0.01) influenced mosquito assemblage structure. Renyi diversity index show that lowland possesses the highest diversity indices. The presence of An. homunculus was associated with Cx. ocellatus and the presence of An. cruzii was associated with Cx. neglectus, Cx. inimitabilis fuscatus and Cx. worontzowi. Anopheles cruzii and An. homunculus were taken from the same bromeliad, however, the co-occurrence between those two species was not statistically significant. CONCLUSIONS: One of the main findings of our study was that differences in species among mosquito assemblages were influenced by landscape characteristics. The bromeliad factor that influenced mosquito abundance and assemblage structure was fullness. The findings of the current study raise important questions about the role of An. homunculus in the transmission of Plasmodium in Serra do Mar, southeastern Atlantic Forest.

Phylogenetic relationships among species of Anopheles (Nyssorhynchus) (Diptera, Culicidae) based on nuclear and mitochondrial gene sequences.

Phylogenetic relationships among 21 species of mosquitoes in subgenus Nyssorhynchus were inferred from the nuclear white and mitochondrial NADH dehydrogenase subunit 6 (ND6) genes. Bayesian phylogenetic methods found that none of the three Sections within Nyssorhynchus (Albimanus, Argyritarsis, Myzorhynchella) were supported in all analyses, although Myzorhynchella was found to be monophyletic at the combined genes. Within the Albimanus Section the monophyly of the Strodei Subgroup was strongly supported and within the Myzorhynchella Section Anopheles antunesi and An. lutzii formed a strongly supported monophyletic group. The epidemiologically significant Albitarsis Complex showed evidence of paraphyly (relative to An. lanei-Myzorhynchella) and discordance across gene trees, and the previously synonomized species of An. dunhami and An. goeldii were recovered as sister species. Finally, there was evidence of complexes in several species, including An. antunesi, An. deaneorum, and An. strodei.