TriatoDex, an electronic identification key to the Triatominae (Hemiptera: Reduviidae), vectors of Chagas disease: Development, description, and performance.

Correct identification of triatomine bugs is crucial for Chagas disease surveillance, yet available taxonomic keys are outdated, incomplete, or both.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.

Redescription of Two Psathyromyia Species (Diptera: Psychodidae), Including Description of the Female of Psathyromyia pradobarrientosi Using Molecular and Morphological Approaches.

The taxonomic identity of two species of sand flies, Psathyromyia pradobarrientosi (Le Pont, Matias, Martinez & Dujardin, 2004) and Psathyromyia runoides (Fairchild & Hertig, 1953) (Diptera, Psychodidae), was evaluated morphologically and molecularly based upon specimens collected in Brazilian states. The morphological component compared collected specimens with paratypes of Pa. runoides and Pa. pradobarrientosi and their descriptions. Phylogenetic analysis of coI sequences of Pa. pradobarrientosi showed a well-supported group distinct from Pa. runoides. Morphologically, Psathyromyia runoides and Pa. pradobarrientosi males are distinguished by characteristics of the aedeagal ducts and parameral sheath in the genitalia; females are distinguished by the number and shape of the teeth in the cibarium and by the shape of the spermathecae. Given the morphological similarity between the males and the absence of the description of the female of Pa. pradobarrientosi, it is possible that specimens previously identified as Pa. runoides in Brazil are in fact Pa. pradobarrientosi.

Methods for detecting insecticide resistance in sand flies: A systematic review.

The classification of insecticide resistance in sand flies populations is based on concepts and methodologies used to characterize the susceptibility profile in mosquitoes. This can generate erroneous and subjective interpretations since they are biologically different organisms. In this context, the goal of this review is to analyze the works and/or articles that aimed at characterizing the susceptibility of sand flies and describing the methodological parameters, in order to improve future works to estimate more accurately the resistance of sand flies to insecticides. Using keywords that refer to the purpose of this review, scientific studies in English, Spanish and Portuguese published until December 2019 were analyzed. A total of 3481 articles were found in searches in four databases (Pubmed, Scopus, BVS and ScienceDirect) and 61 were selected. The panorama of sand-fly resistance revealed 47 populations of sand flies, of species Phlebotomus papatasi, Ph. argentipes e Sergentomyia shorttii, with confirmed resistance, and 28 populations of species Ph. papatasi, Ph. argentipes, Ph. sergenti e Lutzomyia longipalpis. Of the 61 selected studies, only three studies performed comparisons between field and colony phlebotomines, and all colony populations were less susceptible than field populations to at least one tested insecticide. The lethal doses and lethal times of sand flies are very varied, revealing that there is no specific protocol for assessing the susceptibility of sand flies to insecticides. For a quick and early detection of sand flies' resistance to insecticides, we suggest the use of CDC bottle tests with an SRL to estimate the local Dose and Diagnostic Time. Males and females can be used in the same proportion, but with only female sand flies in the control group. Females with engorged abdomen or pregnant should be avoided in the experiment and, if possible, use the F1 generation of field sand flies, up to 5 days old, or at least 100 sand flies to reduce the influence of age on the susceptibility of the population.

Susceptibility of phlebotomine sandflies (Diptera: Psychodidae) collected in the field, to alpha-cypermethrin in four municipalities endemic to leishmaniasis.

Although the chemical control against leishmaniasis began in 1953 in Brazil, little information is available on how this strategy has affected populations of phlebotomine sandflies in the field. The objective of this study was to analyze the susceptibility profile of four populations of phlebotomine sandflies to the insecticide alpha-cypermethrin. Sandflies collected in field in four Brazilian municipalities were evaluated using CDC bottles in different concentrations of alpha-cypermethrin. A total of 1,186 phlebotomine sandflies were used in the bioassays. The LD50 ranged from 1.48 to 2.57 ug/mL in the field populations. For a dose of 5 ug/mL of alpha-cypermethrin, the LT50 and LT95 ranged from 17.9 to 27.5 minutes, and LT95 from 39.7 to 61.5 minutes, respectively. All the populations studied were highly susceptible to the insecticide alpha-cypermethrin. Routine studies are needed to detect changes in sandflies susceptibility to insecticides.

Susceptibility of Aedes aegypti populations to pyriproxyfen in the Federal District of Brazil.

INTRODUCTION: In Brasilia, pyriproxyfen (PPF; 0.01 mg/L) has been used for the larval control of Aedes aegypti mosquitoes since 2016. Information on the susceptibility of Ae. aegypti to PPF, and the development of resistance in populations from the Federal District of Brazil (FD) is limited. It is essential to monitor the susceptibility of Ae. aegypti to insecticides in order to improve vector control strategies. This study aimed to evaluate the susceptibility of Ae. aegypti populations from five areas of Brasilia to PPF. METHODS: We performed dose-response tests to estimate the emergence inhibition and resistance ratio of each field population, including the Rockefeller reference population. We also analyzed egg positivity, and the density and mortality of larvae and pupae. RESULTS: Populations from Vila Planalto (RR50=1.7), Regiment Guards Cavalry (RR50=2.5), and Sub-secretary of Justice Complex (RR50=3.7) presented high susceptibility to PPF, while the RR values of populations from Lago Norte (RR50=7.7) and Varjão (RR50=5.9) were moderately high, suggesting the emergence of insipient resistance to PPF in Brasilia. At 30 ng/mL, the highest larvae mortality rate was 2.7% for the population from Lago Norte, while that of pupae was 92.1% for Varjão and Vila Planalto. CONCLUSIONS: The five populations of Ae. aegypti from the FD are susceptible to PPF and there is a need to monitor the susceptibility of Ae. aegypti in new areas of the FD.

Susceptibility of Aedes aegypti populations to pyriproxyfen in the Federal District of Brazil

Abstract INTRODUCTION: In Brasilia, pyriproxyfen (PPF; 0.01 mg/L) has been used for the larval control of Aedes aegypti mosquitoes since 2016. Information on the susceptibility of Ae. aegypti to PPF, and the development of resistance in populations from the Federal District of Brazil (FD) is limited. It is essential to monitor the susceptibility of Ae. aegypti to insecticides in order to improve vector control strategies. This study aimed to evaluate the susceptibility of Ae. aegypti populations from five areas of Brasilia to PPF. METHODS: We performed dose-response tests to estimate the emergence inhibition and resistance ratio of each field population, including the Rockefeller reference population. We also analyzed egg positivity, and the density and mortality of larvae and pupae. RESULTS: Populations from Vila Planalto (RR50=1.7), Regiment Guards Cavalry (RR50=2.5), and Sub-secretary of Justice Complex (RR50=3.7) presented high susceptibility to PPF, while the RR values of populations from Lago Norte (RR50=7.7) and Varjão (RR50=5.9) were moderately high, suggesting the emergence of insipient resistance to PPF in Brasilia. At 30 ng/mL, the highest larvae mortality rate was 2.7% for the population from Lago Norte, while that of pupae was 92.1% for Varjão and Vila Planalto. CONCLUSIONS: The five populations of Ae. aegypti from the FD are susceptible to PPF and there is a need to monitor the susceptibility of Ae. aegypti in new areas of the FD.

Molecular detection of Trypanosoma sp. and Blastocrithidia sp. (Trypanosomatidae) in phlebotomine sand flies (Psychodidae) in the Federal District of Brazil.

INTRODUCTION: This study describes the occurrence of trypanosomatids in phlebotomines in Brasília, Brazil. METHODS: Two hundred and ten females of 13 sand fly species were analyzed by polymerase chain reaction (PCR) using different molecular markers (D7 24Sα rRNA, kDNA, and ITS1) and sequencing. RESULTS: PCR revealed trypanosomatid-positive samples from Nyssomyia whitmani and Evandromyia evandroi, which were negative by kDNA and ITS1 Leishmania-specific PCRs. DNA sequence analysis of D7 24Sα rRNA amplicons indicated the occurrence of Blastocrithidia sp. and Trypanosoma sp. in Nyssomyia whitmani and Evandromyia evandroi, respectively. CONCLUSIONS: Two trypanosomatid species other than Leishmania sp. were found to circulate in sand flies in Central Brazil.

Bloodsucking insects in rural áreas adjacent to the Corumbá IV hydroelectric dam reservoir, Santo Antônio do Descoberto, Goiás, Brazil

Eutrophic reservoirs of hydroelectric dams may favor the proliferation of macrophytes andbloodsucking insects. Currently, macrophyte overgrowth has been observed in some stretches ofthe Corumbá IV hydroelectric dam (CIV) reservoir. The occurrence of bloodsucking insects wasanalyzed in rural areas adjacent to the CIV reservoir. In two periods (March and July/August) tenhouses in the area with increased macrophyte proliferation (AG) and ten others in the area with lowmacrophyte proliferation (AP) were selected and sampled. Additionally, 100 macrophytes fromeach area were analyzed. A total of 35,788 insects were captured in light traps and 28 percent of thembelonged to families of bloodsucking insects, especially Culicidae. The occurrence of culicids wasdifferent between the AG and AP areas (p<0.05). Mosquitoes were more frequent and abundant inthe AG area. The larval survey showed that 100 percent of the houses visited had potential for mosquitobreeding. Overall, 302 mosquito larvae were collected among macrophytes, mainly in the AG area.It is concluded that there is a higher frequency of mosquitoes in areas with increased macrophyteproliferation, but the CIV reservoir is not the only breeding source of mosquitoes in the studied areas.

Reservatórios de usinas hidrelétricas, quando eutrofizados, podem favorecer a proliferação demacrófitas e insetos hematófagos. Nos últimos anos, tem sido observado um crescimento excessivode macrófitas em alguns trechos do reservatório da hidrelétrica Corumbá IV (CIV). O estudoobjetivou analisar a ocorrência de insetos hematófagos em áreas rurais adjacentes ao reservatório daCIV. Foram selecionadas dez casas em área com grande proliferação de macrófitas (AG) e outras dezem área com baixa proliferação de macrófitas (AP), que foram amostradas em dois períodos (marçoe julho/agosto). Adicionalmente, analisaram-se 100 macrófitas em cada área. Foram capturados35.788 insetos nas armadilhas luminosas e 28 por cento deles pertenciam a famílias de insetos hematófagos,especialmente Culicidae. A ocorrência de culicídeos foi diferente entre as áreas AG e AP (p<0,05),uma vez que estes foram mais frequentes e abundantes na área AG. A pesquisa larvária mostrou que100 por cento das casas visitadas apresentaram potenciais criadouros de mosquitos. No total, 302 larvas demosquitos foram coletadas nas macrófitas, sobretudo na área AG. Pode-se concluir que há maiorfrequência de culicídeos nas áreas com maior proliferação de macrófitas, porém o reservatório CIVnão é o único criadouro de mosquitos nas áreas estudadas.