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1.
Braz J Biol ; 83: e271913, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37194827

RESUMO

Rhodnius neglectus is a wild triatomine, vector of the protozoan Trypanosoma cruzi, which causes Chagas' disease, and feeds on the blood of small mammals, being essential for its growth and reproduction. Accessory glands of the female reproductive tract are important in insect reproduction, but their anatomy and histology in R. neglectus are poorly studied. The aim of this work was to describe the histology and histochemistry of the accessory gland of the female reproductive tract of R. neglectus. The reproductive tract of five females of R. neglectus was dissected and the accessory glands transferred to Zamboni's fixative solution, dehydrated in a crescent series of ethanol, embedded in historesin, sectioned at 2 µm thick, stained with toluidine blue for histological analysis or mercury bromophenol blue for detection of total proteins. The accessory gland R. neglectus is tubular, without branches, opening in the dorsal region of the vagina and differing along its length in proximal and distal regions. In the proximal region, the gland is lined by the cuticle with a layer of columnar cells associated with muscle fibers. In the distal region of the gland, the epithelium has spherical secretory cells with terminal apparatus and conducting canaliculi opening in the lumen through pores in the cuticle. Proteins were identified in the gland lumen, terminal apparatus, nucleus and cytoplasm of secretory cells. The histology of the R. neglectus gland is similar to that found in other species of this genus, but with variations in the shape and size of its distal region.


Assuntos
Doença de Chagas , Rhodnius , Trypanosoma cruzi , Animais , Feminino , Rhodnius/anatomia & histologia , Rhodnius/fisiologia , Insetos Vetores/anatomia & histologia , Insetos Vetores/fisiologia , Trypanosoma cruzi/fisiologia , Reprodução , Mamíferos
2.
J Virol ; 96(15): e0075122, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35867566

RESUMO

Lumpy skin disease virus (LSDV) is a poxvirus that causes severe systemic disease in cattle and is spread by mechanical arthropod-borne transmission. This study quantified the acquisition and retention of LSDV by four species of Diptera (Stomoxys calcitrans, Aedes aegypti, Culex quinquefasciatus, and Culicoides nubeculosus) from cutaneous lesions, normal skin, and blood from a clinically affected animal. The acquisition and retention of LSDV by Ae. aegypti from an artificial membrane feeding system was also examined. Mathematical models of the data were generated to identify the parameters which influence insect acquisition and retention of LSDV. For all four insect species, the probability of acquiring LSDV was substantially greater when feeding on a lesion compared with feeding on normal skin or blood from a clinically affected animal. After feeding on a skin lesion LSDV was retained on the proboscis for a similar length of time (around 9 days) for all four species and for a shorter time in the rest of the body, ranging from 2.2 to 6.4 days. Acquisition and retention of LSDV by Ae. aegypti after feeding on an artificial membrane feeding system that contained a high titer of LSDV was comparable to feeding on a skin lesion on a clinically affected animal, supporting the use of this laboratory model as a replacement for some animal studies. This work reveals that the cutaneous lesions of LSD provide the high-titer source required for acquisition of the virus by insects, thereby enabling the mechanical vector-borne transmission. IMPORTANCE Lumpy skin disease virus (LSDV) is a high consequence pathogen of cattle that is rapidly expanding its geographical boundaries into new regions such as Europe and Asia. This expansion is promoted by the mechanical transmission of the virus via hematogenous arthropods. This study quantifies the acquisition and retention of LSDV by four species of blood-feeding insects and reveals that the cutaneous lesions of LSD provide the high titer virus source necessary for virus acquisition by the insects. An artificial membrane feeding system containing a high titer of LSDV was shown to be comparable to a skin lesion on a clinically affected animal when used as a virus source. This promotes the use of these laboratory-based systems as replacements for some animal studies. Overall, this work advances our understanding of the mechanical vector-borne transmission of LSDV and provides evidence to support the design of more effective disease control programmes.


Assuntos
Sangue , Dípteros , Comportamento Alimentar , Insetos Vetores , Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Aedes/anatomia & histologia , Aedes/virologia , Animais , Bovinos/virologia , Ceratopogonidae/anatomia & histologia , Ceratopogonidae/virologia , Culex/anatomia & histologia , Culex/virologia , Dípteros/anatomia & histologia , Dípteros/fisiologia , Dípteros/virologia , Insetos Vetores/anatomia & histologia , Insetos Vetores/fisiologia , Insetos Vetores/virologia , Doença Nodular Cutânea/virologia , Vírus da Doença Nodular Cutânea/isolamento & purificação , Vírus da Doença Nodular Cutânea/fisiologia , Membranas Artificiais , Muscidae/anatomia & histologia , Muscidae/virologia , Fatores de Tempo
3.
J Med Entomol ; 59(1): 233-239, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34668021

RESUMO

The idea of the existence of Phlebotomus (Larroussius) neglectus (Diptera: Psychodidae) Tonnoir, 1921 in Iran and the skepticism about the existence of Phlebotomus major s.str. Annandale, 1910 had been grown recently in the country. This study reports a combined analysis of mitochondrial and ribosomal DNA target regions of P. major s.l.Annandale, 1910, specimens collected from different parts of Iran. Two different morphotypes were found among the collected samples based on the shape of the aedeagus, ventrally located hairs of the coxite, and parameral sheets. One morphotype seemed similar to P. neglectus Tonnoir 1921 or P. major krimensis Perfiliv1966 (called here MI.N.K.); the other one was similar to P. neglectus and to some extent to P. notus Artemiev & Neronov 1984 (here called MII.N.NO). Cytochrome B, elongation factor 1-alpha, and internal transcribed spacer II loci were amplified, sequenced, and characterized. High sequence homology (98-100%) was observed between P. neglectus and these morphotypes, and phylogenetic analysis was also concordant. Phlebotomus neglectus sequences available in GenBank are located as the sister group of sequences here, particularly near to morphotype MII.N.NO. Moreover, ITS2 locus provides the maximum resolution for differentiation of two morphotypes. Based on achieving results, although a strong support for the presence of P. neglectus was provided, but it is too early to say that P. major s.str. does/does not exist in Iran. This question could be resolved by studying more samples and, most importantly, by comparing the topotypes of P. neglectus and P. major s. str. if possible in the future.


Assuntos
Phlebotomus , Animais , Citocromos b/genética , DNA Ribossômico/genética , Genes de Insetos , Loci Gênicos , Marcadores Genéticos , Insetos Vetores/anatomia & histologia , Insetos Vetores/genética , Irã (Geográfico) , Phlebotomus/anatomia & histologia , Phlebotomus/genética , Filogenia , Psychodidae/anatomia & histologia , Psychodidae/genética , Especificidade da Espécie
4.
Parasit Vectors ; 14(1): 448, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488868

RESUMO

BACKGROUND: An entomological study was conducted in the Canaraua Fetii Special Protection Area in the Dobrogea region, South-Eastern Romania. Four sand fly species were recorded at this location between 1968 and 1970: Phlebotomus neglectus, Ph. balcanicus, Ph. sergenti and Sergentomyia minuta. The most abundant sand fly species recorded at that time were Ph. balcanicus and Se. minuta. In the context of a countrywide study to update the sand fly species diversity, we surveyed the same area, recording also a previously unknown Ph. (Transphlebotomus) sp., for which we provide a formal description here. METHODS: Sand flies were collected between July and August in 2018 and 2019 in three sites from Canaraua Fetii, Dobrogea region, Romania. The general aspect of the landscape is of a canyon (vertical, narrow walls and deep valleys). Species identification was done using both morphological and molecular analyses. RESULTS: Out of 645 collected sand flies, 644 (99.8%) were morphologically identified as Ph. neglectus, while one female specimen (0.2%) was assigned to a previously unknown species, belonging to the subgenus Transphlebotomus. The morphological and molecular examination of this specimen showed that it is a previously unknown species which we formally describe here as Phlebotomus (Transphlebotomus) simonahalepae n. sp. Also, Ph. balcanicus, Ph. sergenti, and Se. minuta (previously recorded in this location) were not present. CONCLUSIONS: The study revealed for the first time the presence of sand flies of the subgenus Transphlebotomus in Romania. Moreover, a new species, Ph. simonahalepae n. sp., was described based on a female specimen, raising the number of species in this subgenus to six. In the investigated natural habitat, the predominant species was Ph. neglectus instead of Ph. balcanicus and Se. minuta (recorded as the predominant species in 1968-1970).


Assuntos
Insetos Vetores/classificação , Insetos Vetores/genética , Phlebotomus/classificação , Phlebotomus/genética , Animais , Ecossistema , Feminino , Insetos Vetores/anatomia & histologia , Masculino , Phlebotomus/anatomia & histologia , Romênia , Especificidade da Espécie
5.
Parasit Vectors ; 14(1): 409, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34407870

RESUMO

BACKGROUND: Tsetse flies (Diptera: Glossinidae) transmit trypanosomiasis (sleeping sickness in humans and nagana in livestock). Several studies have indicated that age, sex, site of capture, starvation and microbiome symbionts, among others, are important factors that influence trypanosome infection in tsetse flies. However, reasons for a higher infection rate in females than in males still largely remain unknown. Considering that tsetse species and sexes of larger body size are the most mobile and the most available to stationary baits, it was hypothesized in this study that the higher trypanosome prevalence in female than in male tsetse flies was a consequence of females being larger than males. METHODS: Black screen fly rounds and Epsilon traps were used to collect tsetse flies in eastern Zambia. Measurement of wing vein length and examination for presence of trypanosomes in the flies were carried out by microscopy. Principal component method was carried out to assess the potential of wing vein length as a predictor variable. The multilevel binary logistic regression method was applied on whole data, one-method data and one-sex data sets to evaluate the hypothesis. RESULTS: Data derived from a total of 2195 Glossina morsitans morsitans were evaluated (1491 males and 704 females). The wing length variable contributed the highest variance percentage (39.2%) to the first principal component. The variable showed significant influence on prevalence of trypanosomes when the analysis was applied on the whole data set, with the log odds for the prevalence of trypanosomes significantly increasing by 0.1 (P = 0.032), per unit increase in wing length. Females had higher trypanosome prevalence rates than males, though not always significant. Furthermore, moving from females to males, wing length significantly reduced by 0.2 (P < 0.0001). CONCLUSIONS: We conclude that wing length is an important predictor variable for trypanosome prevalence in Glossina morsitans morsitans and could partially explain the higher prevalence of trypanosomes in females than in males. However, reasonably representative population data are required for analysis-a serious challenge with the current tsetse sampling methods. Thus, analysis combining data from mobile and stationary methods that include both sexes' data could be useful to verify this hypothesis.


Assuntos
Insetos Vetores/parasitologia , Tripanossomíase/epidemiologia , Moscas Tsé-Tsé/anatomia & histologia , Moscas Tsé-Tsé/parasitologia , Asas de Animais , Animais , Tamanho Corporal , Feminino , Insetos Vetores/anatomia & histologia , Masculino , Prevalência , Fatores Sexuais , Tripanossomíase/transmissão , Zâmbia/epidemiologia
6.
PLoS Negl Trop Dis ; 15(8): e0009682, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34449767

RESUMO

Leishmaniasis is a debilitating disease of the tropics, subtropics and southern Europe caused by Leishmania parasites that are transmitted during blood feeding by phlebotomine sand flies (Diptera: Psychodidae). Using non-invasive micro-computed tomography, we were able to visualize the impact of the laboratory model infection of Lutzomyia longipalpis with Leishmania mexicana and its response to a second blood meal. For the first time we were able to show in 3D the plug of promastigote secretory gel (PSG) and parasites in the distended midgut of whole infected sand flies and measure its volume in relation to that of the midgut. We were also able to measure the degree of opening of the stomodeal valve and demonstrate the extension of the PSG and parasites into the pharynx. Although our pilot study could only examine a few flies, it supports the hypothesis that a second, non-infected, blood meal enhances parasite transmission as we showed that the thoracic PSG-parasite plug in infected flies after a second blood meal was, on average, more than twice the volume of the plug in infected flies that did not have a second blood meal.


Assuntos
Insetos Vetores/anatomia & histologia , Insetos Vetores/parasitologia , Leishmania mexicana/fisiologia , Proteínas de Protozoários/metabolismo , Psychodidae/anatomia & histologia , Psychodidae/parasitologia , Animais , Feminino , Trato Gastrointestinal/anatomia & histologia , Trato Gastrointestinal/parasitologia , Leishmania mexicana/genética , Projetos Piloto , Proteínas de Protozoários/genética , Microtomografia por Raio-X
7.
PLoS Negl Trop Dis ; 15(7): e0009479, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34280193

RESUMO

Phlebotomine sand flies are the main natural vectors of Leishmania, which cause visceral and tegumentary tropical diseases worldwide. However, their taxonomy and evolutionary history remain poorly studied. Indeed, as for many human disease vectors, their small size is a challenge for morphological and molecular works. Here, we successfully amplified unbiased copies of whole genome to sequence thousands of restriction-site associated DNA (RAD) markers from single specimens of phlebotomines. RAD markers were used to infer a fully resolved phylogeny of the subgenus Paraphlebotomus (11 species + 5 outgroups, 32 specimens). The subgenus was not recovered as monophyletic and we describe a new subgenus Artemievus subg. nov. Depaquit for Phlebotomus alexandri. We also confirm the validity of Ph. riouxi which is reinstated as valid species. Our analyses suggest that Paraphlebotomus sensu nov. originated ca 12.9-8.5 Ma and was possibly largely distributed from peri-Mediterranean to Irano-Turanian regions. Its biogeographical history can be summarized into three phases: i) a first split between Ph. riouxi + Ph. chabaudi and other species that may have resulted from the rise of the Saharan belt ca 8.5 Ma; ii) a Messinian vicariant event (7.3-5.3 Ma) during which the prolonged drought could have resulted in the divergence of main lineages; iii) a recent radiation event (3-2 Ma) that correspond to cycles of wet and dry periods in the Middle East and the East African subregions during the Pleistocene. Interestingly these cycles are also hypothetical drivers of the diversification of rodents, in the burrows of which Paraphlebotomus larvae develop. By meeting the challenge of sequencing pangenomics markers from single, minute phlebotomines, this work opens new avenues for improving our understanding of the epidemiology of leishmaniases and possibly other human diseases transmitted by arthropod vectors.


Assuntos
Evolução Molecular , Insetos Vetores/genética , Phlebotomus/genética , Distribuição Animal , Animais , Marcadores Genéticos , Humanos , Insetos Vetores/anatomia & histologia , Insetos Vetores/classificação , Insetos Vetores/fisiologia , Leishmaniose/epidemiologia , Leishmaniose/transmissão , Oriente Médio/epidemiologia , Phlebotomus/anatomia & histologia , Phlebotomus/classificação , Phlebotomus/fisiologia , Filogenia
8.
Parasit Vectors ; 14(1): 298, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34082829

RESUMO

BACKGROUND: The feeding behavior of bloodsucking insects determines the transmission, distribution, host spectrum and evolution of blood parasites in the wild. Conventional wisdom suggests that some vector groups (e.g. black flies, family Simuliidae) are consistently exophagous daytime biters. We aimed to understand more about the exceptions to this pattern by combining targeted trapping and molecular identification of parasites in vectors. METHODS: In this study, we collected black flies in nest boxes used by European rollers Coracias garrulus in southeastern Spain. We molecularly analyzed 434 individual insects, identifying the black fly species caught in the nest boxes, their potential vertebrate blood meals, and the haemosporidian parasite lineages that they carried. RESULTS: Only one black fly species, Simulium rubzovianum, appeared to enter the nest boxes of rollers. Among the trapped specimens, 15% contained vertebrate DNA, which always belonged to rollers, even though only half of those specimens were visibly engorged. Furthermore, 15% of all black flies contained Leucocytozoon lineages, indicating previous feeding on avian hosts but probably not on infected adult rollers. The known vertebrate hosts of the recorded Leucocytozoon lineages suggested that large and/or abundant birds are their hosts. Particularly represented were cavity-nesting species breeding in the vicinity, such as pigeons, corvids and owls. Open-nesting species such as thrushes and birds of prey were also represented. CONCLUSIONS: Our data strongly suggest that S. rubzovianum bites uninfected roller nestlings and infected individuals of other species, potentially incubating adults, inside nest boxes and natural cavities. This simuliid does not appear to have a strong preference for specific host clades. Contrary to the general pattern for the group, and possibly enhanced by the harsh environmental conditions in the study area, this black fly appeared to intensively use and may even have a preference for confined spaces such as cavities for feeding and resting. Preferences of vectors for atypical microhabitat niches where hosts are less mobile may enable social and within-family transmission and parasite speciation in the long term. At the same time, a lack of host preference in concentrated multispecies communities can lead to host switches. Both processes may be underappreciated driving forces in the evolution of avian blood parasites.


Assuntos
Doenças das Aves/sangue , Doenças das Aves/parasitologia , Comportamento Alimentar , Insetos Vetores/parasitologia , Simuliidae/parasitologia , Animais , Doenças das Aves/etiologia , Sangue , Clima Desértico , Feminino , Insetos Vetores/anatomia & histologia , Insetos Vetores/genética , Insetos Vetores/fisiologia , Refeições , Comportamento de Nidação , Filogenia , Simuliidae/anatomia & histologia , Simuliidae/genética , Simuliidae/fisiologia , Espanha
9.
J Med Entomol ; 58(6): 2499-2503, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34021579

RESUMO

Phlebotomus (Transphlebotomus) mascittii Grassi, 1908 (Diptera: Psychodidae) has been found in several European countries. In Spain, sporadic records were reported in the early '80s in Catalonia (Northeast Spain), and it was never detected again. Recent entomological surveys carried out between 2004 and 2020 revealed the presence of several specimens of P. mascittii in Spain. The species identification was confirmed by both morphological and molecular analyses. The analyzed specimens belonged to the haplotype (COI_2) defined by one polymorphic site compared to other European specimens. Phlebotomus mascittii was found in low population densities in rural areas associated with livestock farms and in an urban cemetery during the summer season. This study provides the first records of this species in various localities along the Cantabrian cornice (Northern Spain) and represents its westernmost observation in the Palearctic region. The implications of the finding of this uncommon species are discussed at different levels, with emphasis on its suspected role in the transmission of leishmaniosis.


Assuntos
Distribuição Animal , Insetos Vetores/fisiologia , Phlebotomus/fisiologia , Animais , Feminino , Insetos Vetores/anatomia & histologia , Insetos Vetores/genética , Leishmaniose , Masculino , Phlebotomus/anatomia & histologia , Phlebotomus/genética , Espanha
10.
PLoS One ; 16(4): e0248628, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33886550

RESUMO

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.


Assuntos
Doença de Chagas/epidemiologia , Insetos Vetores , Aplicativos Móveis , Triatominae , Adulto , Animais , Brasil/epidemiologia , Doença de Chagas/transmissão , Feminino , Humanos , Insetos Vetores/anatomia & histologia , Insetos Vetores/classificação , Masculino , Pessoa de Meia-Idade , Triatominae/anatomia & histologia , Triatominae/classificação , Adulto Jovem
11.
Zootaxa ; 4963(3): zootaxa.4963.3.2, 2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33903539

RESUMO

Haplaxius is a large genus of cixiid planthoppers that is widespread in the New World and economically important due to the role of H. crudus in transmitting palm lethal decline phytoplasmas. A new species of Haplaxius, here described as Haplaxius pocococo sp. n., was discovered during survey work on palms in north-central Costa Rica. Placement in Haplaxius is supported by sequence analysis of the COI and 18S genes relative to congeners and by morphological characters.


Assuntos
Cocos , Hemípteros , Insetos Vetores , Animais , Cocos/parasitologia , Costa Rica , Complexo IV da Cadeia de Transporte de Elétrons/genética , Hemípteros/anatomia & histologia , Hemípteros/classificação , Hemípteros/genética , Insetos Vetores/anatomia & histologia , Insetos Vetores/classificação , Insetos Vetores/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
12.
J Parasitol ; 107(2): 289-294, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33844840

RESUMO

Members of the flea family Pulicidae have been the focus of many studies due to their significance as diseases vectors of medical and veterinary importance and their cosmopolitan distribution. They often exhibit variation in morphological features that can make correct species identification and management challenging. This may also apply to Xenopsylla brasiliensis (Baker, 1904), an important plague vector. In the current study, we aimed to provide genetic tools for reliable species identification using a DNA barcoding approach. A total of 73 flea specimens was collected from a native host (Namaqua rock mouse, Micaelamys namaquensis) in South Africa and identified morphologically. In addition, we took measurements of 7 morphological characteristics. Subsequently, we successfully generated barcodes of the mitochondrial cytochrome c oxidase subunit I (COI) gene for X. brasiliensis. We validated this approach by comparing our data to COI sequences from Rwandan X. brasiliensis. While sequences from both regions suggested a close relationship between the 2 X. brasiliensis populations, both haplotype and nucleotide diversity were substantially larger for the South African specimens. This may be attributed to human-assisted spread, differences in habitat, and/or host species sampled and merits further study in the future.


Assuntos
Insetos Vetores/anatomia & histologia , Insetos Vetores/genética , Peste/transmissão , Xenopsylla/anatomia & histologia , Xenopsylla/genética , Animais , Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Infestações por Pulgas/parasitologia , Infestações por Pulgas/veterinária , Variação Genética , Haplótipos , Masculino , Mitocôndrias/enzimologia , Murinae/parasitologia , África do Sul
13.
Parasit Vectors ; 14(1): 195, 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33832518

RESUMO

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 .


Assuntos
Adaptação Fisiológica , Triatominae/genética , Animais , Evolução Biológica , Ecossistema , Equador , Humanos , Insetos Vetores/anatomia & histologia , Insetos Vetores/classificação , Insetos Vetores/genética , Insetos Vetores/fisiologia , Peru , Fenótipo , Filogenia , Seleção Genética , Triatominae/anatomia & histologia , Triatominae/classificação , Triatominae/fisiologia
14.
Parasit Vectors ; 14(1): 164, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33761950

RESUMO

BACKGROUND: Recent climate and environmental changes have resulted in the geographical expansion of Mediterranean Leishmania infantum vectors towards northern latitudes and higher altitudes in different European countries, including Italy, where new foci of canine leishmaniasis have been observed in the northern part of the country. Northern Italy is also an endemic area for mosquito-borne diseases. During entomological surveillance for West Nile virus, mosquitoes and other hematophagous insects were collected, including Phlebotomine sand flies. In this study, we report the results of Phlebotomine sand fly identification during the entomological surveillance conducted from 2017 to 2019. METHODS: The northeastern plain of Italy was divided by a grid with a length of 15 km, and a CO2-CDC trap was placed in each geographical unit. The traps were placed ~ 15 km apart. For each sampling site, geographical coordinates were recorded. The traps were operated every two weeks, from May to November. Sand flies collected by CO2-CDC traps were identified by morphological and molecular analysis. RESULTS: From 2017 to 2019, a total of 303 sand flies belonging to the species Phlebotomus perniciosus (n = 273), Sergentomyia minuta (n = 5), P. mascittii (n = 2) and P. perfiliewi (n = 2) were collected, along with 21 unidentified specimens. The trend for P. perniciosus collected during the entomological surveillance showed two peaks, one in July and a smaller one in September. Sand flies were collected at different altitudes, from -2 m above sea level (a.s.l.) to 145 m a.s.l. No correlation was observed between altitude and sand fly abundance. CONCLUSIONS: Four Phlebotomine sand fly species are reported for the first time from the northeastern plain of Italy. Except for S. minuta, the sand fly species are competent vectors of Leishmania parasites and other arboviruses in the Mediterranean Basin. These findings demonstrate the ability of sand flies to colonize new environments previously considered unsuitable for these insects. Even though the density of the Phlebotomine sand fly population in the plain areas is consistently lower than that observed in hilly and low mountainous areas, the presence of these vectors could herald the onset of epidemic outbreaks of leishmaniasis and other arthropod-borne diseases in areas previously considered non-endemic.


Assuntos
Insetos Vetores/genética , Insetos Vetores/fisiologia , Leishmaniose/veterinária , Phlebotomus/genética , Phlebotomus/fisiologia , Altitude , Distribuição Animal , Animais , Clima , Surtos de Doenças , Cães , Feminino , Geografia , Insetos Vetores/anatomia & histologia , Insetos Vetores/parasitologia , Itália/epidemiologia , Leishmania infantum/fisiologia , Leishmaniose/epidemiologia , Leishmaniose/transmissão , Masculino , Phlebotomus/anatomia & histologia , Phlebotomus/parasitologia , Estações do Ano
15.
Sci Rep ; 11(1): 6536, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33753809

RESUMO

Sharpshooter leafhoppers (Hemiptera: Cicadellidae: Cicadellinae) are important vectors of the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadaceae). This pathogen causes economically significant diseases in olive, citrus, and grapes on multiple continents. Bacterial acquisition and inoculation mechanisms are linked to X. fastidiosa biofilm formation and fluid dynamics in the functional foregut of sharpshooters, which together result in egestion (expulsion) of fluids likely carrying bacteria. One key X. fastidiosa vector is the blue-green sharpshooter, Graphocephala atropunctata (Signoret, 1854). Herein, a 3D model of the blue-green sharpshooter functional foregut is derived from a meta-analysis of published microscopy images. The model is used to illustrate preexisting and newly defined anatomical terminology that is relevant for investigating fluid dynamics in the functional foregut of sharpshooters. The vivid 3D illustrations herein and supplementary interactive 3D figures are suitable resources for multidisciplinary researchers who may be unfamiliar with insect anatomy. The 3D model can also be used in future fluid dynamic simulations to better understand acquisition, retention, and inoculation of X. fastidiosa. Improved understanding of these processes could lead to new targets for preventing diseases caused by X. fastidiosa.


Assuntos
Sistema Digestório/ultraestrutura , Hemípteros/ultraestrutura , Insetos Vetores/ultraestrutura , Doenças das Plantas/microbiologia , Animais , Citrus/microbiologia , Sistema Digestório/anatomia & histologia , Hemípteros/anatomia & histologia , Hemípteros/microbiologia , Insetos Vetores/anatomia & histologia , Insetos Vetores/microbiologia , Olea/microbiologia , Vitis/microbiologia , Xylella/patogenicidade
16.
Am J Trop Med Hyg ; 104(2): 653-655, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33399039

RESUMO

Chagas disease is a potentially life-threatening illness caused by the protozoan Trypanosoma cruzi and transmitted, mainly, by hematophagous insects of the Triatominae subfamily. In Brazil, there are currently about 66 triatomine species distributed throughout the country's 27 states. Triatoma infestans is considered as a species of great vectorial importance, mainly because of its biological characteristics, such as the high degree of anthropophilia, adaptation to the home environment, ability to withstand long periods of fasting, and present a wide geographical distribution. Taking into account the epidemiological importance of these species, we carried out the first report of T. infestans in the Espírito Santo, Brazil, and development of an identification key for all species notified in that state, based on cytogenetic data. This information is important because they contribute to the direction of epidemiological surveillance activities carried out by vector control programs of the Espírito Santo, Brazil.


Assuntos
Doença de Chagas/transmissão , Insetos Vetores , Triatominae , Animais , Brasil , Doença de Chagas/prevenção & controle , Análise Citogenética , Humanos , Insetos Vetores/anatomia & histologia , Insetos Vetores/genética , Triatominae/anatomia & histologia , Triatominae/genética
17.
Parasit Vectors ; 14(1): 90, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514419

RESUMO

BACKGROUND: Spots and coloring patterns evaluated quantitatively can be used to discriminate and identify possible cryptic species. Species included in the Triatoma dimidiata (Reduviidae: Triatominae) complex are major disease vectors of Chagas disease. Phylogenetic studies have defined three haplogroups for Mexico and part of Central America. We report here our evaluation of the possibility of correctly discriminating these three T. dimidiata haplogroups using the pattern of the dorsal spots. METHODS: Digital images of the dorsal region of individuals from the three haplogroups were used. Image processing was used to extract primary and secondary variables characterizing the dorsal spot pattern. Statistical analysis of the variables included descriptive statistics, non-parametric Kruskal-Wallis tests, discriminant function analysis (DFA) and a neural classification network. RESULTS: A distinctive spot pattern was found for each haplogroup. The most differentiated pattern was presented by haplogroup 2, which was characterized by its notably larger central spots. Haplogroups 1 and 3 were more similar to each other, but there were consistent differences in the shape and orientation of the spots. Significant differences were found among haplogroups in almost all of the variables analyzed, with the largest differences seen for relative spot area, mean relative area of central spots, central spots Feret diameter and lateral spots Feret diameter and aspect ratio. Both the DFA and the neural network had correct discrimination values of > 90%. CONCLUSIONS: Based on the results of this analysis, we conclude that the spot pattern can be reliably used to discriminate among the three haplogroups of T. dimidiata in Mexico, and possibly among triatomine species.


Assuntos
Triatoma/classificação , Animais , América Central , Doença de Chagas/transmissão , Classificação , Insetos Vetores/anatomia & histologia , Insetos Vetores/classificação , México , Pigmentação , Triatoma/anatomia & histologia
18.
Parasit Vectors ; 13(1): 455, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32894173

RESUMO

BACKGROUND: The protozoan Trypanosoma cruzi circulates in semiarid areas of northeastern Brazil in distinct ecotopes (sylvatic, peridomestic and domestic) where Triatoma brasiliensis Neiva, 1911 is the most important Chagas disease vector. In this study, we analyzed microevolutionary and demographic aspects of T. brasiliensis populations at the ecotypic, micro and macro-geographic scales by combining morphometrics and molecular results. Additionally, we aimed to address the resolution of both markers for delimiting populations in distinct scales. METHODS: We sampled populations of T. brasiliensis from distinct ecotypic and geographic sites in the states Rio Grande do Norte (RN) and Paraíba (PB). The geometric morphometry was carried out with 13 landmarks on the right wings (n = 698) and the genetic structure was assessed by sequencing a region of cytochrome b mitochondrial gene (n = 221). Mahalanobis distance (MD) and coefficient of molecular differentiation (ΦST) were calculated among all pairs of populations. The results of comparisons generated MD and ΦST dendrograms, and graphics of canonical variate analysis (CVA). RESULTS: Little structure was observed for both markers for macro-geographic scales. Mantel tests comparing geographic, morphometric and genetic matrices showed low correlation (all R2 < 0.35). The factorial graphics built with the CVA evidenced population delimitation for the morphometric data at micro-geographic scales. CONCLUSIONS: We believe that T. brasiliensis carries in its genotype a source of information to allow the phenotypical plasticity across its whole distribution for shaping populations, which may have caused a lack of population delimitation for CVAs in morphometric analysis for macro-geographic scale analysis. On the other hand, the pattern of morphometric results in micro-geographic scales showed well-defined groups, highlighting the potential of this tool to inferences on the source for infestation.


Assuntos
Triatoma , Animais , Brasil/epidemiologia , Doença de Chagas/transmissão , Citocromos b/genética , Genes de Insetos , Genética Populacional , Insetos Vetores/anatomia & histologia , Insetos Vetores/genética , Dinâmica Populacional , Triatoma/anatomia & histologia , Triatoma/genética
19.
Parasit Vectors ; 13(1): 463, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32912306

RESUMO

BACKGROUND: The Culicoides fauna of Algeria has been historically investigated, leading to the description of many new species by Kieffer in the 1920s, Clastrier in the 1950s or Callot in the 1960s and to a comprehensive inventory by Szadziewski in the 1980s. The emergence of bluetongue in the late 1990s enhanced Culicoides collections made in the country over the last two decades, but information remained mostly unpublished. The aim of this study is therefore to provide a comprehensive and updated checklist of Culicoides biting midge species in Algeria. METHODS: The literature (published and grey, in French and in English) from 1920 to date on Culicoides collections in Algeria was collected and analyzed in the light of the current taxonomic and systematic knowledge and methods. Fresh Culicoides material was also analyzed using light/suction trap collections carried out from November 2015 to September 2018 in nine localities of the 'wilayah' of Tiaret (northwestern Algeria). Slide mounted specimens were identified morphologically using the interactive identification key IIKC and original descriptions. Specimens were then compared with non-type material originating from different countries and partly with type material. RESULTS: A total of 13,709 Culicoides, belonging to at least 36 species within 10 subgenera, were examined leading to 10 new records in Algeria, including C. chiopterus, C. dewulfi, C. navaiae, C. grisescens, C. paradoxalis, C. shaklawensis, C. simulator, C. univittatus, C. achrayi and C. picturatus. These new records and all previous records provided by the literature review were discussed. CONCLUSIONS: We propose a Culicoides checklist for the Algerian fauna of 59 valid species, including species mainly with a large Palaearctic distribution and a specific Mediterranean distribution, and only a few species from the Afrotropical region. Among them, several species, mainly of the subgenera Avaritia and Culicoides, are confirmed or probable vectors of arboviruses important in animal health.


Assuntos
Ceratopogonidae/classificação , Insetos Vetores/classificação , Argélia , Distribuição Animal , Animais , Bluetongue/transmissão , Vírus Bluetongue/fisiologia , Bovinos , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/virologia , Ceratopogonidae/anatomia & histologia , Ceratopogonidae/fisiologia , Lista de Checagem , Feminino , Insetos Vetores/anatomia & histologia , Insetos Vetores/fisiologia , Masculino
20.
Neotrop Entomol ; 49(5): 722-738, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32720065

RESUMO

We present surveys of derbid planthoppers associated with coconut (Cocos nucifera L.) and oil palm (Elaeis guineensis Jacq.) collected in Northeastern (Sergipe) and North (Pará and Roraima) Brazil. The surveys were intended to contribute to our knowledge of possible vectors of phytoplasmas or other phloem-restricted plant pathogens. Eight derbid taxa were found, two in the subfamily Cedusinae, tribe Cedusini (Cedusa yipara Kramer and C. yowza Kramer) and six in the subfamily Derbinae, tribe Cenchreini: Herpis sp., Persis pugnax Stål, Omolicna anastomosa (Caldwell), O. nigripennis (Caldwell), and two new species in the genus Agoo Bahder & Bartlett are described here. Genus-level features between Omolicna and Agoo are discussed and a key to the species of Agoo is provided.


Assuntos
Arecaceae , Cocos , Hemípteros/anatomia & histologia , Hemípteros/classificação , Animais , Brasil , Feminino , Insetos Vetores/anatomia & histologia , Insetos Vetores/classificação , Masculino , Phytoplasma
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