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Background: Triatomines are biological vectors of Trypanosoma cruzi, the etiological agent of Chagas Disease (CD) and have various mammalian hosts. This study evaluated the entomological indicators and food sources of triatomines in Petrolina in the semi-arid region of Brazil, where CD is endemic., Methods: Triatomines were captured indoors and outdoors through an active search and entomological indices (household and natural infections) were calculated. Parasitological analyses were performed through microscopic visualization using Giemsa-stained insect feces, and DNA sequencing was employed to identify food sources from the gut contents of 82 insects (9.05%) that were better preserved., Results: We captured triatomines (906) in peridomicile (807) and intradomicile (99): Triatoma brasiliensis (84.7%, 767 specimens), Triatoma spp. (8.2%, 74 specimens), T. pseudomaculata (6.5%, 59 specimens), Rhodnius spp. (0.4%, four specimens), R. nasutus (0.1%, one specimen), and T. sordida (0.1%, one specimen). The household infestation index is 11.8%. Thirty-five triatomines were infected (33 T. brasiliensis and two T. pseudomaculata), corresponding to a natural infection index of 3.8%. The identified food sources were human T. pseudomaculata and T. brasiliensis, dogs for T. brasiliensis and rodents (Mus musculus) for T. brasiliensis., Conclusions: The results reinforce the need to intensify CD diagnosis, surveillance, and control actions, as an increase in entomological indices was recorded. Blood from humans and domestic and synanthropic animals was detected in the infected triatomines, suggesting a risk of CD vector transmission in Petrolina. As CD is a zoonosis, multidisciplinary and intersectoral CD surveillance must be conducted in the context of the One Health.

Background: Monitoring and analysing the infection rates of the vector of Trypanosoma cruzi, that causes Chagas disease, helps assess the risk of transmission., Objectives: A study was carried out on triatomine in the State of Paraná, Brazil, between 2012 and 2021 and a comparison was made with a previous study. This was done to assess the risk of disease transmission., Methods: Ecological niche models based on climate and landscape variables were developed to predict habitat suitability for the vectors as a proxy for risk of occurrence., Findings: A total of 1,750 specimens of triatomines were recorded, of which six species were identified. The overall infection rate was 22.7%. The areas with the highest risk transmission of T. cruzi are consistent with previous predictions in municipalities. New data shows that climate models are more accurate than landscape models. This is likely because climate suitability was higher in the previous period., Main Conclusion: Regardless of uneven sampling and potential biases, risk remains high due to the wide presence of infected vectors and high environmental suitability for vector species throughout the state and, therefore, improvements in public policies aimed at wide dissemination of knowledge about the disease are recommended to ensure the State remains free of Chagas disease.

Background: Triatomine bugs transmit Chagas disease across Latin America, where vector control-surveillance is increasingly decentralized. Locally run systems often deal with highly diverse native-vector faunas-plus, in some areas, domestic populations of non-native species. Flexible entomological-risk indicators that cover native and non-native vectors and can support local decision-making are therefore needed., Methods: We present a local-scale entomological-risk score ("TriatoScore") that leverages and builds upon information on the ecology-behavior and distribution-biogeography of individual triatomine bug species. We illustrate our approach by calculating TriatoScores for the 417 municipalities of Bahia state, Brazil. For this, we (i) listed all triatomine bug species recorded statewide; (ii) derived a "species relevance score" reflecting whether each species is native/non-native and, if native, whether/how often it invades/colonizes dwellings; (iii) mapped each species' presence by municipality; (iv) for native vectors, weighted presence by the proportion of municipal territory within ecoregions occupied by each species; (v) multiplied "species relevance score" × "weighted presence" to get species-specific "weighted scores"; and (vi) summed "weighted scores" across species to get municipal TriatoScores. Using standardized TriatoScores, we then grouped municipalities into high/moderate/low entomological-risk strata., Results: TriatoScores were higher in municipalities dominated by dry-to-semiarid ecoregions than in those dominated by savanna-grassland or, especially, moist-forest ecoregions. Bahia's native triatomines can maintain high to moderate risk of vector-borne Chagas disease in 318 (76.3%) municipalities. Historical elimination of Triatoma infestans from 125 municipalities reduced TriatoScores by ~ 27% (range, 20-44%); eight municipalities reported T. infestans since Bahia was certified free of Trypanosoma cruzi transmission by this non-native species. Entomological-risk strata based on TriatoScores agreed well with Bahia's official disease-risk strata, but TriatoScores suggest that the official classification likely underestimates risk in 42 municipalities. Of 152 municipalities failing to report triatomines in 2006-2019, two and 71 had TriatoScores corresponding to, respectively, high and moderate entomological risk., Conclusions: TriatoScore can help control-surveillance managers to flexibly assess and stratify the entomological risk of Chagas disease at operationally relevant scales. Integrating eco-epidemiological, demographic, socioeconomic, or operational data (on, e.g., local-scale dwelling-infestation or vector-infection frequencies, land-use change and urbanization, housing conditions, poverty, or the functioning of control-surveillance systems) is also straightforward. TriatoScore may thus become a useful addition to the triatomine bug control-surveillance toolbox., (© 2021. The Author(s).)

Background: Meccus' taxonomy has been quite complex since the first species of this genus was described by Burmeister in 1835 as Conorhinus phyllosoma. In 1859 the species was transferred to the genus Meccus and in 1930 to Triatoma. However, in the twentieth century, the Meccus genus was revalidated (alteration corroborated by molecular studies) and, in the twenty-first century, through a comprehensive study including more sophisticated phylogenetic reconstruction methods, Meccus was again synonymous with Triatoma. Events of natural hybridization with production of fertile offspring have already been reported among sympatric species of the T. phyllosoma subcomplex, and experimental crosses demonstrated reproductive viability among practically all species of the T. phyllosoma subcomplex that were considered as belonging to the genus Meccus, as well as between these species and species of Triatoma. Based on the above, we carried out experimental crosses between T. longipennis (considered M. longipennis in some literature) and T. mopan (always considered as belonging to Triatoma) to evaluate the reproductive compatibility between species of the T. phyllosoma complex. In addition, we have grouped our results with information from the literature regarding crosses between species that were grouped in the genus Meccus with Triatoma, in order to discuss the importance of experimental crosses to confirm the generic reorganization of species., Results: The crosses between T. mopan female and T. longipennis male resulted in viable offspring. The hatching of hybrids, even if only in one direction and/or at low frequency, demonstrates reproductive compatibility and homeology between the genomes of the parents., Conclusion: Considering that intergeneric crosses usually do not result in viable offspring in Triatominae, the reproductive compatibility observed between the T. phyllosoma subcomplex species considered in the Meccus genus with species of the Triatoma genus shows that there is "intergeneric" genomic compatibility, which corroborates the generic reorganization of Meccus in Triatoma.

Direct test over the gut material from triatomine vectors and xenodiagnosis over mammalian hosts are classical techniques for Trypanosoma cruzi parasitological diagnosis. Nevertheless, negative results can be a source of uncertainty. Experimental models have allowed evaluating the tissue invasion of different strains of T. cruzi, but conventional techniques for tissue biopsies involve time-consuming and elaborated procedures and have low sensitivity. Gut material of collected triatomines (microscopically negative) (n = 114), material of mammal xenodiagnoses (microscopically negative) (n = 138), and biopsy material (microscopically negative) from experimentally infected animals (n = 34) with isolates from endemic areas of Chagas' disease from Venezuela were used for DNA extraction and PCR for the amplification of kinetoplast DNA (kDNA) and satellite DNA (sDNA) of T. cruzi. Positive PCR was observed in 53.6% of collected triatomine material, 15.8% of parasitological negative xenodiagnosis material, and 70.6% in biopsies, revealing underestimation by the parasitological tests and the valour of this analysis with preserved material. Anzoátegui was the state with the highest percentage of infection, and the triatomine species Rhodnius prolixus and Panstrongylus geniculatus had the highest percentages of infection. Didelphis marsupialis and Canis familiaris were the most infected by T. cruzi revealed by PCR of xenodiagnosis material. In addition, the PCR technique allowed demonstrating the invasion of T. cruzi in all tissues analyzed, constituting a molecular marker of tissue invasion.

Correct identification of triatomine bugs is crucial for Chagas disease surveillance, yet available taxonomic keys are outdated, incomplete, or both. Here we present TriatoDex, an Android app-based pictorial, annotated, polytomous key to the Triatominae. TriatoDex was developed using Android Studio and tested by 27 Brazilian users. Each user received a box with pinned, number-labeled, adult triatomines (33 species in total) and was asked to identify each bug to the species level. We used generalized linear mixed models (with user- and species-ID random effects) and information-theoretic model evaluation/averaging to investigate TriatoDex performance. TriatoDex encompasses 79 questions and 554 images of the 150 triatomine-bug species described worldwide up to 2017. TriatoDex-based identification was correct in 78.9% of 824 tasks. TriatoDex performed better in the hands of trained taxonomists (93.3% vs. 72.7% correct identifications; model-averaged, adjusted odds ratio 5.96, 95% confidence interval [CI] 3.09-11.48). In contrast, user age, gender, primary job (including academic research/teaching or disease surveillance), workplace (including universities, a reference laboratory for triatomine-bug taxonomy, or disease-surveillance units), and basic training (from high school to biology) all had negligible effects on TriatoDex performance. Our analyses also suggest that, as TriatoDex results accrue to cover more taxa, they may help pinpoint triatomine-bug species that are consistently harder (than average) to identify. In a pilot comparison with a standard, printed key (370 tasks by seven users), TriatoDex performed similarly (84.5% correct assignments, CI 68.9-94.0%), but identification was 32.8% (CI 24.7-40.1%) faster on average-for a mean absolute saving of ~2.3 minutes per bug-identification task. TriatoDex holds much promise as a handy, flexible, and reliable tool for triatomine-bug identification; an updated iOS/Android version is under development. We expect that, with continuous refinement derived from evolving knowledge and user feedback, TriatoDex will substantially help strengthen both entomological surveillance and research on Chagas disease vectors., Competing Interests: JASB received salary from H2J Comunicação & Marketing, Brasília, Brazil and MRA received salary from Real Comércio e Indústria de Alumínio Ltd. This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents, products in development or marketed products to declare.

Background: Triatomine bugs, the vectors of Chagas disease, associate with vertebrate hosts in highly diverse ecotopes. It has been proposed that occupation of new microhabitats may trigger selection for distinct phenotypic variants in these blood-sucking bugs. Although understanding phenotypic variation is key to the study of adaptive evolution and central to phenotype-based taxonomy, the drivers of phenotypic change and diversity in triatomines remain poorly understood., Methods/results: We combined a detailed phenotypic appraisal (including morphology and morphometrics) with mitochondrial cytb and nuclear ITS2 DNA sequence analyses to study Rhodnius ecuadoriensis populations from across the species' range. We found three major, naked-eye phenotypic variants. Southern-Andean bugs primarily from vertebrate-nest microhabitats (Ecuador/Peru) are typical, light-colored, small bugs with short heads/wings. Northern-Andean bugs from wet-forest palms (Ecuador) are dark, large bugs with long heads/wings. Finally, northern-lowland bugs primarily from dry-forest palms (Ecuador) are light-colored and medium-sized. Wing and (size-free) head shapes are similar across Ecuadorian populations, regardless of habitat or phenotype, but distinct in Peruvian bugs. Bayesian phylogenetic and multispecies-coalescent DNA sequence analyses strongly suggest that Ecuadorian and Peruvian populations are two independently evolving lineages, with little within-lineage phylogeographic structuring or differentiation., Conclusions: We report sharp naked-eye phenotypic divergence of genetically similar Ecuadorian R. ecuadoriensis (nest-dwelling southern-Andean vs palm-dwelling northern bugs; and palm-dwelling Andean vs lowland), and sharp naked-eye phenotypic similarity of typical, yet genetically distinct, southern-Andean bugs primarily from vertebrate-nest (but not palm) microhabitats. This remarkable phenotypic diversity within a single nominal species likely stems from microhabitat adaptations possibly involving predator-driven selection (yielding substrate-matching camouflage coloration) and a shift from palm-crown to vertebrate-nest microhabitats (yielding smaller bodies and shorter and stouter heads). These findings shed new light on the origins of phenotypic diversity in triatomines, warn against excess reliance on phenotype-based triatomine-bug taxonomy, and confirm the Triatominae as an informative model system for the study of phenotypic change under ecological pressure .

Triatomines (Hemiptera: Reduviidae) are the insect vectors of Trypanosoma cruzi, the causative agent of Chagas disease. The gut bacterial communities affect the development of T. cruzi inside the vector, making the characterization of its composition important in the understanding of infection development. We collected 54 triatomine bugs corresponding to four genera in different departments of Colombia. DNA extraction and PCR were performed to evaluate T. cruzi presence and to determine the discrete typing unit (DTU) of the parasite. PCR products of the bacterial 16S rRNA gene were pooled and sequenced. Resulting reads were denoised and QIIME 2 was used for the identification of amplicon sequence variants (ASVs). Diversity (alpha and beta diversity) and richness analyses, Circos plots, and principal component analysis (PCA) were also performed. The overall T. cruzi infection frequency was 75.9%, with TcI being the predominant DTU. Approximately 500,000 sequences were analyzed and 27 bacterial phyla were identified. The most abundant phyla were Proteobacteria (33.9%), Actinobacteria (32.4%), Firmicutes (19.6%), and Bacteroidetes (7.6%), which together accounted for over 90% of the gut communities identified in this study. Genera were identified for these main bacterial phyla, revealing the presence of important bacteria such as Rhodococcus, Serratia, and Wolbachia. The composition of bacterial phyla in the gut of the insects was significantly different between triatomine species, whereas no significant difference was seen between the state of T. cruzi infection. We suggest further investigation with the evaluation of additional variables and a larger sample size. To our knowledge, this study is the first characterization of the gut bacterial structure of the main triatomine genera in Colombia., Competing Interests: The authors have declared that no competing interests exist.

Background: Kissing bugs (Triatominae) are blood-feeding insects best known as the vectors of Trypanosoma cruzi, the causative agent of Chagas' disease. Considering the high epidemiological relevance of these vectors, their biology and bacterial symbiosis remains surprisingly understudied. While previous investigations revealed generally low individual complexity but high among-individual variability of the triatomine microbiomes, any consistent microbiome determinants have not yet been identified across multiple Triatominae species., Methods: To obtain a more comprehensive view of triatomine microbiomes, we investigated the host-microbiome relationship of five Triatoma species sampled from white-throated woodrat (Neotoma albigula) nests in multiple locations across the USA. We applied optimised 16S rRNA gene metabarcoding with a novel 18S rRNA gene blocking primer to a set of 170 T. cruzi-negative individuals across all six instars., Results: Triatomine gut microbiome composition is strongly influenced by three principal factors: ontogeny, species identity, and the environment. The microbiomes are characterised by significant loss in bacterial diversity throughout ontogenetic development. First instars possess the highest bacterial diversity while adult microbiomes are routinely dominated by a single taxon. Primarily, the bacterial genus Dietzia dominates late-stage nymphs and adults of T. rubida, T. protracta, and T. lecticularia but is not present in the phylogenetically more distant T. gerstaeckeri and T. sanguisuga. Species-specific microbiome composition, particularly pronounced in early instars, is further modulated by locality-specific effects. In addition, pathogenic bacteria of the genus Bartonella, acquired from the vertebrate hosts, are an abundant component of Triatoma microbiomes., Conclusion: Our study is the first to demonstrate deterministic patterns in microbiome composition among all life stages and multiple Triatoma species. We hypothesise that triatomine microbiome assemblages are produced by species- and life stage-dependent uptake of environmental bacteria and multiple indirect transmission strategies that promote bacterial transfer between individuals. Altogether, our study highlights the complexity of Triatominae symbiosis with bacteria and warrant further investigation to understand microbiome function in these important vectors. Video abstract.

Introduction: Triatomine bugs are vectors of Trypanosoma cruzi, the etiological agent of Chagas disease., Methods: Triatomine bugs were collected and identified following established protocols. In addition, infection with T. cruzi was detected by microscopic and molecular analysis., Results: We captured an adult male specimen of the Eratyrus cuspidatus species that has not been reported in the state of Campeche., Conclusions: This finding provides new information on the distribution of E. cuspidatus in Mexico. However, more studies are needed to determine their epidemiological significance.

Leptoglossus occidentalis (Heidemann) is an invasive species introduced in Europe, Asia, and most recently South America. In the present study, we report the overreaction situation caused by this bug in Chile, as it has been confused with kissing bugs (Reduviidae: Triatominae), Chagas' disease vectors. During 2018 and first months of 2019, we received 74 alleged cases of kissing bugs to confirm identification. From these, a total of 63 were identified as L. occidentalis, representing a 85% of the total denounces. Additionally, the first bite case in a human is described. The situation caused by L. occidentalis in Chile is discussed, and an illustrated table is provided to correctly identify this species and tell it apart from Triatomines. It is concluded that L. occidentalis is well established in Chile, and it is necessary to educate the population on recognition of the bug and to avoid overreaction as the species can inflict painful bites, but not transmit any disease., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

This study aimed to describe the spatial distribution and assess entomological indicators of synanthropic triatomines in Piaui State, Northeastern Brazil. We used surveillance data on the detection, identification and assessment of natural infection with trypanosomatids from triatomines in the State from 2014 to 2017. The State was divided into four macroregions. In relation to the dispersion rates of triatomines, they were much lower in the North, when compared to Southwest, Southeast and Central North macroregions. Infestation rates were higher in the Southwest and Southeast and intradomicile infestation rates varied during the study period, reaching high values in all regions. Insects belonging to the species Triatoma brasiliensis complex, Triatoma pseudomaculata, Triatoma sordida, and to the genus Panstrongylus spp. and Rhodnius spp. were collected during this period. T. brasiliensis was collected from all four regions of the State, but more frequently in those located in the Southeast. A similar pattern was observed for T. pseudomaculata. T. sordida was detected in the municipalities in the Southeast and Southwest regions, and less frequently in the Central North municipalities. Rhodnius spp. was detected in the Central North and North regions, and Panstrongylus spp. in the Central North and Southeast regions. The highest trypanosomatid-positivity rate of T. brasiliensis and Panstrongylus spp. was in the Southeast region. A significant proportion of the municipalities of Piaui State presents entomological parameters that indicate a risk of Chagas disease by vector transmission.

Background: The identification of Trypanosoma cruzi and blood-meal sources in synanthropic triatomines is important to assess the potential risk of Chagas disease transmission. We identified T. cruzi infection and blood-meal sources of triatomines caught in and around houses in the state of Bahia, northeastern Brazil, and mapped the occurrence of infected triatomines that fed on humans and domestic animals., Methods: Triatominae bugs were manually captured by trained agents from the Epidemiologic Surveillance team of Bahia State Health Service between 2013 and 2014. We applied conventional PCR to detect T. cruzi and blood-meal sources (dog, cat, human and bird) in a randomized sample of triatomines. We mapped triatomine distribution and analyzed vector hotspots with kernel density spatial analysis., Results: In total, 5906 triatomines comprising 15 species were collected from 127 out of 417 municipalities in Bahia. The molecular analyses of 695 triatomines revealed a ~10% T. cruzi infection rate, which was highest in the T. brasiliensis species complex. Most bugs were found to have fed on birds (74.2%), and other blood-meal sources included dogs (6%), cats (0.6%) and humans (1%). Trypanosoma cruzi-infected triatomines that fed on humans were detected inside houses. Spatial analysis showed a wide distribution of T. cruzi-infected triatomines throughout Bahia; triatomines that fed on dogs, humans, and cats were observed mainly in the northeast region., Conclusions: Synanthropic triatomines have a wide distribution and maintain the potential risk of T. cruzi transmission to humans and domestic animals in Bahia. Ten species were recorded inside houses, mainly Triatoma sordida, T. pseudomaculata, and the T. brasiliensis species complex. Molecular and spatial analysis are useful to reveal T. cruzi infection and blood-meal sources in synanthropic triatomines, identifying areas with ongoing threat for parasite transmission and improving entomological surveillance strategies.

Introduction: Oral transmission of acute Chagas disease is an emerging public health concern. This study aimed to detect insect fragments in experimentally contaminated food, by comparing triatomines with other insects., Methods: Food samples were experimentally contaminated with insects, processed to recover their fragments by light filth, and analyzed by microscopy and Polymerase Chain Reaction (PCR)., Results: Morphological differences between coleopteran and triatomine insects were observed in microscopic images. PCR was efficient in amplifying Triatominae DNA in the experimentally contaminated food., Conclusions: This methodology could be utilized by food analysts to identify possible insect contamination in food samples.

Introduction: Trypanosoma cruzi is the etiological agent of Chagas disease (CD), a zoonotic infection transmitted by triatomine bug vectors to human beings. Although the story of this parasitic infection was born in Brazil and here this has made major step forward information, the same cannot be said about the actual distribution of the triatomine vector in several areas of this country. The aim of this study was to assess the occurrence of triatomine species in an endemic region for CD in Northeastern Brazil., Methods: A retrospective study was performed using data obtained from 2008 to 2017. All information was provided by the V Gerência Regional de Saúde of the state of Pernambuco. The spatial distribution of triatomine species was analyzed by drawing a map using the Quantum geographic information system., Results: A total of 4,694 triatomine specimens (469.4 ± 221.2 per year) were collected during the period 2008-2017, with 94.5% (4,434/4,694) at the intradomicile and 5.5% (260/4,694) at peridomicile environment. Of all arthropods collected, 92.5% (4,340/4,694) and 7.5% (354/4,694) were adults and nymphs, respectively. The species most frequently detected were Panstrongylus lutzi (30.36%), Triatoma brasiliensis (26.12%), Triatoma pseudomaculata (22.43%), and Panstrongylus megistus (20.54%)., Conclusions: These data contribute to a better understanding of the distribution of T. cruzi infection in the Northeastern region of Brazil. Preventive measures based on vector control should be implemented in the study area in order to reduce the burden this neglected tropical disease.

The blood-sucking insects of the subfamily Triatominae are vectors of Chagas disease, the most impairing protozoan parasitic infection in Latin America. Among the five tribes known in the subfamily, one of the least studied is Cavernicolini. It has only two species within Cavernicola genus (Barber, 1937), little is known about the biochemistry of the species of this genus, therefore, using MALDI-TOF MS we provide a better understanding of the two species and differentiates them. The distinction was made by the different spectral profile of the species, where C. lenti presents unique signals in many regions, while the C. pilosa shows high-intensity signals and m/z in high bands. The application of digital mass spectrometry combined with chemometric methods was able to accurately distinguish two species of the genus Cavernicola., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Triatomines are vectors of Trypanosoma cruzi , the etiological agent of Chagas disease, which affects between 6 and 12 million people in Latin America, with an incidence rate of 12 thousand cases per year. In the Ceara State, the predominance of the caatinga biome, coupled with a large rural area with precarious human habitations, provides several s shelters for these insects. In this study, we determined the spatiotemporal distribution of triatomine dispersion rates in the Cariri region, Southern Ceara and ascertained the possible association between these rates with socioeconomic and environmental factors. Dispersion rates (number of positive localities/number of searched localities × 100) were analyzed regarding 13 municipalities from the Ceara State, from 2009 to 2013. Socioeconomic and environmental variables collected from national research institutes were associated with the dispersion rates and their local empirical Bayesian estimates. All the municipalities recorded dispersion rates over 10% in all years, and 11 municipalities had average rates over 40% for the period of study. Significant differences were observed among the municipality means. The highest rates were observed in Antonina do Norte and Potengi. According to the correlation analysis, the proportion between the occupied population and the total population showed a significant negative correlation, as well as the percentage of the population who lives under adequate sanitary conditions. Both, the percentage of revenues from external sources and the percentage of urban households in reforested blocks had a significant positive correlation. Our results show that socioeconomic and environmental variables can be factors that contribute to both, the maintenance and the reduction of the elevated dispersion rates observed in the study area. Similar researches that encompass more municipalities from that region may reinforce Chagas disease surveillance and control in the Northeast of Brazil.

Vector-borne Chagas disease is endemic to the Americas and imposes significant economic and social burdens on public health. In a previous contribution, we presented an automated identification system that was able to discriminate among 12 Mexican and 39 Brazilian triatomine (Hemiptera: Reduviidae) species from digital images. To explore the same data more deeply using machine-learning approaches, hoping for improvements in classification, we employed TensorFlow, an open-source software platform for a deep learning algorithm. We trained the algorithm based on 405 images for Mexican triatomine species and 1,584 images for Brazilian triatomine species. Our system achieved 83.0 and 86.7% correct identification rates across all Mexican and Brazilian species, respectively, an improvement over comparable rates from statistical classifiers (80.3 and 83.9%, respectively). Incorporating distributional information to reduce numbers of species in analyses improved identification rates to 95.8% for Mexican species and 98.9% for Brazilian species. Given the 'taxonomic impediment' and difficulties in providing entomological expertise necessary to control such diseases, automating the identification process offers a potential partial solution to crucial challenges., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The reduviid subfamily Triatominae, also called kissing bugs, are vectors of Chagas disease, which is one of the most seriously neglected tropical parasitic diseases. Only three complete mitochondrial genomes of kissing bugs from the genus Triatoma have been sequenced to date. To better understand the diversity of mitochondrial genomes and the evolution of kissing bugs, mitochondrial genomes of three kissing bugs, Triatoma migrans, Panstrongylus rufotuberculatus, and Rhodnius pictipes, were sequenced using next-generation sequencing and a comparative mitochondrial genomic analysis of three genera and two tribes in Triatominae was conducted. Kissing bug mitochondrial genomes shared a similar pattern of nucleotide composition, gene order, and structure of control region. The comparison among orthologous protein-coding genes indicated that different genes had different rates of molecular evolution and six genes (ND1, ND2, ND4L, ND5, ND6, and ATP8) had higher evolutionary rates than other protein-coding genes. Phylogenetic analyses inferred from mitochondrial genome sequences supported a sister relationship between Triatominae and Stenopodainae, and the genus Triatoma was paraphyletic. The present study revealed the high conservation of the mitochondrial genome organization of kissing bugs and highlighted the utility of mitochondrial genomes in the phylogenetic study of Triatominae., (Copyright © 2019. Published by Elsevier B.V.)

Introduction: The ecoepidemiological situation in the State of Rio Grande do Norte, Brazil is characterized by frequent invasion and colonization of domiciliary units (DUs) by several triatomine species, with high rates of natural infection by Trypanosoma cruzi. METHODS: We evaluated the possibility of vector transmission of T. cruzi based on records of the occurrence of domiciled triatomines collected by the Secretariat of State for Public Health from 2005 to 2015. During this period, 67.7% (113/167) of municipalities conducted at least one active search and 110 recorded the presence of insects in DUs. These activities were more frequent in municipalities considered to have a high and medium-level risk of T. cruzi transmission., Results: Of 51,569 captured triatomines, the most common species were Triatoma brasiliensis (47.2%) and T. pseudomaculata (40.2%). Colonies of T. brasiliensis, T. pseudomaculata, T. petrocchiae, Panstrongylus lutzi, and Rhodnius nasutus were also recorded in the intradomicile and peridomicile. Natural infection by trypanosomatids was detected in 1,153 specimens; the highest rate was found in R. nasutus (3.5%), followed by T. brasiliensis (2.5%) and T. pseudomaculata (2.4%). There have been high levels of colonization over the years; however, not all infested DUs have been sprayed. CONCLUSIONS: This is the first report of intradomicile and peridomicile colonization by P. lutzi. These results demonstrate the risk of new cases of infection by T. cruzi and reinforce the need for continuous entomological surveillance in the State of Rio Grande do Norte.

Introduction: The present study reports the presence of triatomines in natural, peridomestic, and intradomicile environments in Itacoatiara municipality, state of Amazonas, a non-endemic region for Chagas disease., Methods: Active search was performed inside tree trunks, and palm trees, residences, and peridomiciles localized near the forest area., Results: Twenty adults and ten triatomines nymphs were collected, fifteen of which were from natural forests, thirteen from intradomiciles, and two from peridomicile areas., Conclusions: The new records of adults and nymphs of triatomines in the intra- and peridomiciles suggest the adoption of prophylactic measures for vector surveillance in the study area.

Introduction: The domestic and peridomestic presence of Triatoma infestans depends on several factors, such as human behavior, vector behavior, ecology, and the environment., Methods: This work was conducted in 139 domiciliary units, where triatomines were captured and risk factors in domiciles and peridomicilies were recorded. Household dwellers were interviewed to obtain information about practices regarding this disease and entomological indicators were calculated., Results: Infestation indices were 59.7% for house compounds, 4.3% for domestic areas and 58.3% for the peridomestic areas. Intradomicile infestation was significantly associated with housing characteristics. The presence of chicken coops in peridomicilies was associated with an increased risk of infestation. Of the respondents, 80% did not recognize the importance of the peridomiciliary structures for triatomine control and had infested peridomicilies., Conclusions: The results show the importance of peridomiciles as refuge sites for Triatominae bugs; however, household dwellers do not perceive peridomiciles as areas that favor the presence of vectors. Actions for raising awareness about factors that favor the presence of triatomines are needed to improve the conditions of peridomiciliary environments.

Chagas disease represents one of the major health issue in Latin America. Epidemiological control is focused on disease vectors, so studies on the ecology of triatomine vectors constitute a central strategy. Recently, research at large spatial scale has been produced, and authors commonly rely on the assumption that geographical regions presenting good environmental conditions for most vector species are also those with high risk of infection. In the present work, we provide an explicit evaluation for this assumption. Employing species distribution models and epidemiological data for Chagas disease in Brazilian territory, our results show that species richness is a poor predictor for the observed pattern of Chagas disease occurrence. Species composition proved to be a better predictor. We stress that research on macroecology of infectious diseases should go beyond the analysis of biodiversity patterns and consider human infections as a central part of the focal ecological systems.

The genus Psammolestes within the subfamily Triatominae and tribe Rhodniini comprises the species Psammolestes arthuri , Psammolestes coreodes , and Psammolestes tertius , all potential vectors of Chagas disease. A feature of Psammolestes is their close association with birds, which makes them an interesting model for evolutionary studies. We analyzed cytogenetically Psammolestes spp., with the aim of contributing to the genetic and evolutionary knowledge of these vectors. All species of the Psammolestes showed the same chromosomal characteristics: chromocenter formed only by sex chromosomes X and Y, karyotype 2 n = 22 and constitutive heterochromatin, and AT base pairs restricted to the sex chromosome Y. These results corroborate the monophyly of the genus and lead to the hypothesis that during the derivation of P. tertius , P. coreodes , and P. arthuri from their common ancestor, there was no reorganization in the number or structure of chromosomes.

The species of the genus Mepraia Mazza, Gajardo Tobar and Jörg (Hemiptera, Reduviidae:Triatominae) exhibit polymorphism in their hemelytra. The females of all species are always micropterous, but the males can be micropterous, brachypterous, or macropterous. Mepraia gajardoi Frías, Henry and González (Hemiptera: Reduviidae) males are always brachypterous, Mepraia parapatrica Frías-Lasserre (Hemiptera: Reduviidae) males are macropterous or brachypterous and Mepraia spinolai (Porter) (Hemiptera: Reduviidae) males are macropterous, brachypterous, or micropterous. Here, we determined distinctive characteristics of the hemelytra of the males of these three species and found that the length of the hemelytra of the brachypterous males in these three species differs statistically, as does their shape and morphology. These differences are particularly apparent at the apex of the hemelytra, the anterior part of the corium, in the morphology and number of the ctenidia of coaptors, and presence or absence of the cross vein of the hemelytra. Based on this, we propose a key based on hemelytra characteristics to identify the males of the three Mepraia species.

Background: Eggs have epidemiological and taxonomic importance in the subfamily Triatominae, which contains Chagas disease vectors. The metric properties (size and shape) of eggs are useful for distinguishing between close species, or different geographical populations of the same species., Methods: We examined the effects of egg viability on its metric properties, and the possible consequences on species recognition. Four species were considered: Panstrongylus chinai, P. howardi and Triatoma carrioni (tribe Triatomini), and Rhodnius ecuadoriensis (tribe Rhodniini). Digitization was performed on pictures taken when the viability of the egg could not clearly be predicted by visual inspection. We then followed development to separate viable from non-viable eggs, and the metric changes associated with viability status of the eggs were tested for species discrimination (interspecific difference)., Results: The shape of the complete contour of the egg provided satisfactory species classification (95% of correct assignments, on average), with improved scores (98%) when discarding non-viable eggs from the comparisons. Using only non-viable eggs, the scores dropped to 90%. The morphometric differences between viable and non-viable eggs were also explored (intraspecific comparison). A constant metric change observed was a larger variance of size and shape in non-viable eggs. For all species, larger eggs, or eggs with larger operculum, were more frequently non-viable. However, these differences did not allow for an accurate prediction regarding egg viability., Conclusions: The strong taxonomic signal present in egg morphology was affected by the level of viability of the eggs. The metric properties as modified in non-viable eggs presented some general trends which could suggest the existence of an optimum phenotype for size and for shape. Globally, viable eggs tended to have intermediate or small sizes, and presented a less globular shape in the Triatomini, or a relatively wider neck in Rhodnius ecuadoriensis.

Triatoma vitticeps is a Chagas disease vector that was found infected with Trypanosoma cruzi in homes. As this species is endemic from Brazil (Bahia, Espírito Santo, Minas Gerais, and Rio de Janeiro) and no study comparing the specimens from different Brazilian states was conducted, we analyzed the genetic distance (16S rDNA, Cyt b, and COI mitochondrial genes) and the chromosomal characteristics for T. vitticeps from Minas Gerais, Rio de Janeiro, and Espírito Santo. All specimens showed the same cytogenetic characteristics. On the other hand, the different mitochondrial genes demonstrated high intraspecific variation between the genetic distances of T. vitticeps from different states ranging from 2.3% to 7.2%. Based on this, our results suggest that possibly what is characterized as T. vitticeps is a complex of cryptic species (or subspecies).

This note reports on occurrences of triatomine species in the city of Sao Paulo, Brazil, registered between 1988 and 2017. Records of triatomines captured in Sao Paulo are based on specimens received spontaneously from Health Surveillance Centers, Health Centers and Zoonosis Control Centers in the city as well as from citizens. Species were identified morphologically at the Public Health Entomology Laboratory, Faculty of Public Health, University of Sao Paulo, where the triatomines, which are vectors of Chagas disease, were tested for Trypanosoma cruzi infection. The first reported occurrence of triatomine bugs in urban Sao Paulo was in 1988. The specimen, which was captured in Jardim Sao Luiz district, was from the genus Panstrongylus and was registered as Panstrongylus sp. but was not sexed. Since this first recorded occurrence, the following species have been found in the city: Panstrongylus geniculatus (2 occurrences), P. megistus (15 occurrences), Triatoma infestans (1 occurrence) and T. sordida (3 occurrences). In this paper, the importance of reporting occurrences of triatomine bugs in the city of Sao Paulo, one of the largest metropolis in the world, is discussed with an emphasis on P. megistus. The occurrences discussed here indicate the importance of entomological surveillance for these vectors even in urban centers although the possibility of vector transmission of Chagas disease in these centers is very low.

The Triatominae subfamily is composed of 153 hematophagous species that are potential vectors of Trypanosoma cruzi , the etiological agent of Chagas disease. Karyotypic studies in triatomines were initiated in 1909. There are 92 karyotypes described, all grouped into the tribes Rhodniini and Triatomini. Recently, a phylogenetic study of the triatomines that combines molecular data with geological changes was performed. We now discuss how the karyotype evolved with the diversification of the triatomines.

Triatomines are haematophagous insects involved in the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease. The vector competence of these arthropods can be highly variable, depending on the species. A precise identification is therefore crucial for the epidemiological surveillance of T. cruzi and the determination of at-risk human populations. To circumvent the difficulties of morphological identification and the lack of comprehensiveness of the GenBank database, we hereby propose an alternative method for triatomine identification. The femurs of the median legs of triatomines from eight different species from French Guiana were subjected to matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) analysis. Method evaluation was performed on fresh specimens and was applied to dry specimens collected between 1991 and 2003. Femur-derived protein extracts provided reproducible spectra within the same species along with significant interspecies heterogeneity. Validation of the study by blind test analysis provided 100% correct identification of the specimens in terms of the species, sex and developmental stage. MALDI-TOF mass spectrometry appears to be a powerful tool for triatomine identification, which is a major step forward in the fight against Chagas disease.

Background: Insects operate complex humoral and cellular immune strategies to fend against invading microorganisms. The majority of these have been characterized in Drosophila and other dipterans. Information on hemipterans, including Triatominae vectors of Chagas disease remains incomplete and fractionated., Results: We identified putative immune-related homologs of three Triatominae vectors of Chagas disease, Triatoma pallidipennis, T. dimidiata and T. infestans (TTTs), using comparative transcriptomics based on established immune response gene references, in conjunction with the predicted proteomes of Rhodnius prolixus, Cimex lecticularis and Acyrthosiphon pisum hemimetabolous. We present a compressive description of the humoral and cellular innate immune components of these TTTs and extend the immune information of other related hemipterans. Key homologs of the constitutive and induced immunity genes were identified in all the studied hemipterans., Conclusions: Our results in the TTTs extend previous observations in other hemipterans lacking several components of the Imd signaling pathway. Comparison with other hexapods, using published data, revealed that the absence of various Imd canonical components is common in several hemimetabolous species.

Background: Chagas disease in the Brazilian Amazon Region was previously regarded as an enzootic disease of wild animals. More recently, in situations where humans have penetrated the wild ecotope or where triatomines and/or wild animals (marsupials) have invaded human homes resulting in disease transmission, Chagas disease has come to be regarded as an anthropozoonosis. We found that the highest incidence of infection due to Trypanosoma cruzi and Chagas disease occurred among piassaba fibre gatherers and their families., Objectives: Considering the results of previous surveys, we conducted a new survey of piassaba gatherers and their families in the creeks of the Aracá, Curuduri, Demini, Ererê and Padauiri rivers, which are tributaries on the left bank of the Negro River, in the municipality of Barcelos; Barcelos-Caurés highway; Negro River in Santa Isabel of the Negro River; and Marié River, on the right bank of the Negro River., Methods: A questionnaire was applied to 482 piassaba gatherers and their families who accompanied them. We collected 5-mL blood samples (with permission from each subject), separated the serum, and performed serological tests using indirect immunofluorescence and conventional and recombinant enzyme-linked immunosorbent assays (ELISA). We performed brief clinical examination and electrocardiograms. Only 273 subjects attended our field base for detailed clinical examination and electrocardiogram., Findings and Main Conclusions: The questionnaire revealed that 100% of the 482 patients recognised the triatomine Rhodnius brethesi, which they had seen in the piassaba plantation and 81% in their field huts. A total of 79% of subjects had previously been bitten by this vector and 21% did not know. The 25 subjects seropositive for T. cruzi infection (5.2%) stated that they had been bitten more than 10 times by this insect. Of the 273 subjects who underwent electrocardiogram, 22% showed conditions that were possibly attributable to Chagas disease or other cardiovascular disease.

In this chapter, we review and update current knowledge about the evolution, systematics, and biogeography of the Triatominae (Hemiptera: Reduviidae)-true bugs that feed primarily on vertebrate blood. In the Americas, triatomines are the vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Despite declining incidence and prevalence, Chagas disease is still a major public health concern in Latin America. Triatomines occur also in the Old World, where vector-borne T. cruzi transmission has not been recorded. Triatomines evolved from predatory reduviid bugs, most likely in the New World, and diversified extensively across the Americas (including the Caribbean) and in parts of Asia and Oceania. Here, we first discuss our current understanding of how, how many times, and when the blood-feeding habit might have evolved among the Reduviidae. Then we present a summary of recent advances in the systematics of this diverse group of insects, with an emphasis on the contribution of molecular tools to the clarification of taxonomic controversies. Finally, and in the light of both up-to-date phylogenetic hypotheses and a thorough review of distribution records, we propose a global synthesis of the biogeography of the Triatominae. Over 130 triatomine species contribute to maintaining T. cruzi transmission among mammals (sometimes including humans) in almost every terrestrial ecoregion of the Americas. This means that Chagas disease will never be eradicated and underscores the fact that effective disease prevention will perforce require stronger, long-term vector control-surveillance systems., (© 2018 Elsevier Ltd All rights reserved.)

This article reports a list with 912 specimens of the subfamily Triatominae deposited in the Entomological Collection of the Faculty of Public Health of the University of Sao Paulo. The collection is composed of 1 holotype, 3 alotypes, 15 paralectotypes, 77 paratypes, distributed in 5 tribes and 12 genera: Tribus Alberprosenini: genus Alberprosenia Martinez & Carcavallo, 1977; Tribus Bolboderini: genus Microtriatoma Prosen & Martinez, 1952; Tribus Cavernicolini: genus Cavernicola Barber, 1937; Tribus Rhodnini: genus Psammolestes Bergroth, 1941; genus Rhodnius Stal, 1859; Tribus Triatomini: genus Dipetalogaster Usinger 1939; genus Eratyrus Stal 1859; genus Hermanlentia Jurberg & Galvão, 1997; genus Linshcosteus Distant, 1904; 1944; genus Panstrongylus Berg 1879; genus Paratriatoma Barber 1938; genus Triatoma Laporte 1833.

Introduction: Chagas disease surveillance requires current knowledge on synanthropic triatomines. We analyzed the occurrence and Trypanosoma cruzi infection rates of triatomine bugs in central Brazil, during 2012-2014., Methods: Triatomines were collected inside or around houses, and T. cruzi infection was determined by optical microscopy and conventional/quantitative polymerase chain reaction., Results: Of the 2706 triatomines collected, Triatoma sordida was the most frequent species in Goiás State, whereas Panstrongylus megistus predominated in the Federal District. Parasites identified were T. cruzi, T. rangeli, and Blastocrithidia sp., Conclusions: P. megistus and T. sordida sustained the risk of T. cruzi transmission to humans in central Brazil.

Background: Triatoma sordida and Triatoma pseudomaculata are frequently captured triatomine species in the Brazilian savannah and caatinga biomes, respectively, and in Brazilian domiciles., Objectives: This study identified eco-epidemiological changes in Chagas disease in northern Minas Gerais state, Brazil, and considered the influence of environmental shifts and both natural and anthropogenic effects., Methods: Domicile infestation and Trypanosoma cruzi infection rates were obtained from triatomines and sylvatic reservoirs during the following two time periods: the 1980s and 2007/2008. Entomological and climatic data with land cover classification derived from satellite imagery were integrated into a geographic information system (GIS), which was applied for atmospheric correction, segmentation, image classification, and mapping and to analyse data obtained in the field. Climatic data were analysed and compared to land cover classifications., Results: A comparison of current data with data obtained in the 1980's showed that T. sordida colonised domiciliary areas in both periods, and that T. pseudomaculata did not colonise these areas. There was a tendency toward a reduction in T. cruzi infection rates in sylvatic reservoirs, and of triatomines captured in both households and in the sylvatic environment. T. sordida populations have reduced in the sylvatic environment, while T. pseudomaculata showed an expanding trend in the region compared to counts observed in the 1980's in the sylvatic environment. This may be related to high deforestation rates as well as gradual increases in land surface temperature (LST) and temperatures along the years., Main Conclusions: Our results suggest a geographical expansion of species into new biomes as a result of anthropogenic and climatic changes that directly interfere with the reproductive and infection processes of vectors.

Introduction:: Studying the feeding preferences of triatomines is an important entomological surveillance tool, since continuous surveillance of the disease is necessary., Methods:: The precipitin reaction was used to describe the feeding preferences of triatomines along with their natural infection by flagellates similar to Tyrpanosoma cruzi. Six hundred eighty-seven insects were examined, including Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus lutzi., Results:: Sixty-nine (10%) of 687 triatomines examined tested positive for flagellates similar to T. cruzi, and 8 (1.2%) of these fed on human blood., Conclusions:: This study found potential transmitters of Chagas disease both inside and outside the domiciliar environment.

Active Trypanosoma cruzi transmission persists in the Gran Chaco region, which is considered hyperendemic for Chagas disease. Understanding domestic and sylvatic transmission cycles and therefore the relationship between vectors and mammalian hosts is crucial to designing and implementing improved effective control strategies. Here we describe the species of triatomine vectors and the sylvatic mammal reservoirs of T. cruzi, in different localities of the Paraguayan and Bolivian Chaco. We identify the T. cruzi genotypes discrete typing units (DTUs) and provide a map of their geographical distribution. A total of 1044 triatomines and 138 sylvatic mammals were captured. Five per cent of the triatomines were microscopically positive for T. cruzi (55 Triatoma infestans from Paraguay and one sylvatic Triatoma guasayana from Bolivia) and 17 animals (12·3%) comprising eight of 28 (28·5%) Dasypus novemcinctus, four of 27 (14·8%) Euphractus sexcinctus, three of 64 (4·7%) Chaetophractus spp. and two of 14 (14·3%) Didelphis albiventris. The most common DTU infecting domestic triatomine bugs was TcV (64%), followed by TcVI (28%), TcII (6·5%) and TcIII (1·5%). TcIII was overwhelmingly associated with armadillo species. We confirm the primary role of T. infestans in domestic transmission, armadillo species as the principal sylvatic hosts of TcIII, and consider the potential risk of TcIII as an agent of Chagas disease in the Chaco.

Background: Since the early 1990s, programs to control Chagas disease in South America have focused on eradicating domiciliary Triatoma infestans, the main vector. Seroprevalence studies of the chagasic infection are included as part of the vector control programs; they are essential to assess the impact of vector control measures and to monitor the prevention of vector transmission., Objective: To assess the interruption of domiciliary vector transmission of Chagas disease by T. infestans in Paraguay by evaluating the current state of transmission in rural areas., Methods: A survey of seroprevalence of Chagas disease was carried out in a representative sample group of Paraguayans aged one to five years living in rural areas of Paraguay in 2008. Blood samples collected on filter paper from 12,776 children were tested using an enzyme-linked immunosorbent assay. Children whose serology was positive or undetermined (n = 41) were recalled to donate a whole blood sample for retesting. Their homes were inspected for current triatomine infestation. Blood samples from their respective mothers were also collected and tested to check possible transmission of the disease by a congenital route., Findings: A seroprevalence rate of 0.24% for Trypanosoma cruzi infection was detected in children under five years of age among the country's rural population. Our findings indicate that T. cruzi was transmitted to these children vertically. The total number of infected children, aged one to five years living in these departments, was estimated at 1,691 cases with an annual incidence of congenital transmission of 338 cases per year., Main Conclusion: We determined the impact of vector control in the transmission of T. cruzi, following uninterrupted vector control measures employed since 1999 in contiguous T. infestans-endemic areas of Paraguay, and this allowed us to estimate the degree of risk of congenital transmission in the country.

Understanding the biological parameters of some triatomine subspecies of Meccus phyllosomus (Burmeister) is a crucial first step in estimating the epidemiologic importance of this group. Biological parameters related to hatching, lifetime, number of blood meals to molt, percentage of females at the end of the cycle, number of laid eggs, and mortality for each instar of 3 M. phyllosomus subspecies [M. p. mazzottii (Usinger), M. p. pallidipennis (Stål), and M. p. phyllosomus] and their laboratory hybrids were evaluated and compared. No significant differences (P > 0.05) were found among the experimental hybrids (MaPa, MaPhy, PaPhy) and reciprocal cohorts. In 5 (hatching, number of blood meals to molt, accumulative mortality, percentage of females, and mean number of laid eggs) of the 6 studied parameters (with the exception of development time), the hybrid cohorts had better fitness results than the parental cohorts involved in each set of crosses. The increase in hybrid fitness found in our study could lead to an increase in the epidemiologic risks caused by transmission of Trypanosoma cruzi to humans., (© 2015 Institute of Zoology, Chinese Academy of Sciences.)

Background: Egg morphometrics in the Triatominae has proved to be informative for distinguishing tribes or genera, and has been based generally on traditional morphometrics. However, more resolution is required, allowing species or even population recognition, because the presence of eggs in the domicile could be related to the species ability to colonize human dwellings, suggesting its importance as a vector., Results: We explored the resolution of modern morphometric methods to distinguish not only tribes and genera, but also species or geographic populations in some important Triatominae. Four species were considered, representing two tribes and three genera: Panstrongylus chinai and P. howardi, Triatoma carrioni and Rhodnius ecuadoriensis. Within R. ecuadoriensis, two geographical populations of Ecuador were compared. For these comparisons, we selected the most suitable day of egg development, as well as the possible best position of the egg for data capture. The shape of the eggs in the Triatominae does not offer true anatomical landmarks as the ones used in landmark-based morphometrics, except for the egg cap, especially in eggs with an evident "neck", such as those of the Rhodniini. To capture the operculum shape variation, we used the landmark- and semilandmark-based method. The results obtained from the metric properties of the operculum were compared with the ones provided by the simple contour of the whole egg, as analyzed by the Elliptic Fourier Analysis. Clear differences could be disclosed between the genera, between the species - among which two very close species (P. chinai and P. howardi), as well as between two allopatric, conspecific populations. The whole egg contour (including the operculum) produced reclassification scores much more satisfactory than the ones obtained using the operculum only., Conclusions: We propose the outline-based approach as the most convenient characterization tool to identify unknown eggs at the species or population levels.

Introduction: Domestic and wild triatomines in the department of Santander have an epidemiological impact, as recently they have been linked to outbreaks of acute Chagas disease. The analysis of their diversity and temporal variation contributes to the understanding of their biology and ecology in one of the most endemic areas of the country., Objectives: To analyze triatominae diversity in two regions of Santander., Materials and Methods: We analyzed the triatomine records for Santander contained in the CINTROP-UIS entomology lab database. We grouped the information for two regions: the Middle Magdalena area and the Andean region, and for each one we designed species accumulation and range-abundance curves, we calculated diversity and equality indices, and we analyzed colonization and temporal variation or persistence of the community., Results: Ninety five percent of triatomines came from the Andean area and 4.57% from Magdalena Medio, with nine and ten species each. The dominant species in the Andean area were Rhodnius prolixus and Triatoma dimidiata while in Magdalena Medio they were Rhodnius pallescens and Panstrongylus geniculatus. We found a greater diversity and richness in Middle Magdalena compared to the Andean area. The temporal variation showed persistence of communities over time., Conclusions: Results revealed differences in the diversity of the two regions and the potential of wild species to occupy artificial ecotopes. Triatomines intrusion and the recent involvement of wild species in the transmission of Trypanosoma cruzi emphasize the need to further investigate the ecology of these vectors in order to guide population control strategies.

Triatomines are blood-sucking insects that transmit the causative agent of Chagas disease, Trypanosoma cruzi. Despite being recognized as a difficult task, the correct taxonomic identification of triatomine species is crucial for vector control in Latin America, where the disease is endemic. In this context, we have developed a web and mobile tool based on PostgreSQL database to help healthcare technicians to overcome the difficulties to identify triatomine vectors when the technical expertise is missing. The web and mobile version makes use of real triatomine species pictures and dichotomous key method to support the identification of potential vectors that occur in Brazil. It provides a user example-driven interface with simple language. TriatoKey can also be useful for educational purposes., Database Url: http://triatokey.cpqrr.fiocruz.br., (© The Author(s) 2017. Published by Oxford University Press.)

Chagas disease is amongst the ten most important neglected tropical diseases but knowledge on the diversification of its vectors, Triatominae (Hemiptera: Reduviidae), is very scarce. Most Triatominae species occur in the Americas, and are all considered potential vectors. Despite its amazing ecological vignette, there are remarkably few evolutionary studies of the whole subfamily, and only one genome sequence has been published. The young age of the subfamily, coupled with the high number of independent lineages, are intriguing, yet the lack of genome-wide data makes it a challenge to infer the phylogenetic relationships within Triatominae. Here we synthesize what is known, and suggest the next steps towards a better understanding of how this important group of disease vectors came to be., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Hematophagous insects of the subfamily Triatominae include several species with a large variety of shapes, behavior and distribution. They have great epidemiological importance since most of them transmit the flagellated protozoan Trypanosoma cruzi, the etiologic agent of Chagas disease. In this subfamily several cases of species hybridization have been reported under experimental and natural conditions. Mepraia is a genus of Triatominae endemic in Chile, responsible for transmitting T. cruzi in the sylvatic cycle. This genus includes three species, M. gajardoi, M. spinolai and M. parapatrica; however, the differentiation of M. parapatrica as a separate species remains controversial considering the possible occurrence of introgression/hybridization processes in some populations of this putative species. Mepraia species show conspicuous wing polymorphism, and it has been proposed that the genes related to wings are linked to the Y chromosome, thus wingless males could not engender winged progeny. In order to determine the degree of reproductive isolation and to assess the wing phenotype in the offspring, we performed experimental crosses between the two most divergent Mepraia species (M. gajardoi and M. spinolai) together with chromosome analyses of hybrid progenies. Although fertile F 1 hybrids were obtained in only one direction of crossing, we verified the existence of different isolation mechanisms between parental species, including hybrid breakdown. The occurrence of winged males in the offspring of wingless parental males suggests that the wing character is not linked to the Y chromosome., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Current working classifications of Chagas disease vectors rely on a loose mix-up of biological and operational matters. They are therefore confusing and ineffective. I propose a very simple classification that makes biological sense and can be operationally useful. It considers a four-level hierarchy of species (which can be native or non-native); populations (either wild or non-wild); infestation foci (natural, domestic or peridomestic); and individual bugs (which can be solitary house-invaders or part of a hidden infestation focus). This classification translates into a clear, algorithmic scheme for triatomine control-surveillance that may be useful at every operationally relevant scale, from multi-country initiatives to on-site control-surveillance action.

The subfamily Triatominae (Hemiptera, Reduviidae) includes 150 species of blood-sucking insects, vectors of Chagas disease or American trypanosomiasis. Karyotypic information reveals a striking stability in the number of autosomes. However, this group shows substantial variability in genome size, the amount and distribution of C-heterochromatin, and the chromosome positions of 45S rDNA clusters. Here, we analysed the karyotypes of 41 species from six different genera with C-fluorescence banding in order to evaluate the base-pair richness of heterochromatic regions. Our results show a high heterogeneity in the fluorescent staining of the heterochromatin in both autosomes and sex chromosomes, never reported before within an insect subfamily with holocentric chromosomes. This technique allows a clear discrimination of the heterochromatic regions classified as similar by C-banding, constituting a new chromosome marker with taxonomic and evolutionary significance. The diverse fluorescent patterns are likely due to the amplification of different repeated sequences, reflecting an unusual dynamic rearrangement in the genomes of this subfamily. Further, we discuss the evolution of these repeated sequences in both autosomes and sex chromosomes in species of Triatominae.

Molecular systematics is a remarkable approach for understanding the taxonomic traits and allows the exploration of the inter-population dynamics of several species in the Triatominae subfamily that are involved in Trypanosoma cruzi transmission. Compared to other relevant species that transmit vector-borne diseases, such as some species of the Diptera, there are relatively few nuclear genetic markers available for systematic studies in the Triatominae subfamily. Molecular systematic studies performed on Triatominae are based on mitochondrial gene fragments and, less frequently, on nuclear ribosomal genes or spacers. Due to the fact that these markers can occasionally present problems such as nuclear mitochondrial genes (NUMTs) or intra-genomic variation for high gene copy numbers, it is necessary to use additional nuclear markers to more reliably address the molecular evolution of Triatominae. In this study, we performed phylogenetic analysis using the nuclear elongation factor-1 alpha (EF-1α) gene in individuals from 12 species belonging to the Triatomini and Rhodniini tribes. Genetic diversities and phylogenetic topologies were compared with those obtained for the mitochondrial 16S rRNA and Cytochrome b (cyt b) genes, as well as for the D2 variable region of the ribosomal 28S rRNA gene. These results indicate that the EF-1α marker exhibits an intermediate level of diversity compared to mitochondrial and nuclear ribosomal genes, and that phylogenetic analysis based on EF-1α is highly informative for resolving deep phylogenetic relationships in Triatominae, such as tribe or genera., (Copyright © 2016 Elsevier B.V. All rights reserved.)