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Informações acerca de potenciais criadouros naturais de flebotomíneos sempre foram de fundamental interesse epidemiológico. Contudo, são poucas as informações advindas dos diversos estudos realizados até o momento. Isto se deve principalmente às dificuldades de localização e extração dos imaturos que se desenvolvem no solo e matéria orgânica do chão de florestas. No presente estudo o modelo modificado de armadilha de emergência foi testado na Vila do Pitinga, município de Presidente Figueiredo, Estado do Amazonas, a fim de localizar potenciais criadouros naturais. Vinte e sete indivíduos de nove espécies (Lutzomyia umbratilis,L. monstruosa,L. ayrozai,L. anduzei,L. trichopyga,L. davisi,L. geniculata,L. georgii e L. saulensis) foram coletados. Lutzomyia umbratilis foi a espécie com maior número de indivíduos, 10, representando 37,1% do total. A produção de flebotomíneos foi estimada em 2,2 flebotomíneos por 100 m² por dia. Em setembro, mês com maior número de indivíduos, esta produção foi de 5,8.Information concerning the potential natural breeding sites of phlebotomine sandflies are of high epidemiological importance. However, few studies have been conducted on the subject. This is due especially to the difficulties in finding as well as extracting immature sandflies that develop in the soil and organic matter of the forest floor. In the present study, a modified emergence trap model was tested in order to find potential breeding sites. This model was tested in the Pitinga Village, situated in the Presidente Figueredo municipality, in the State of Amazonas. Twenty-seven individuals belonging to nine species (Lutzomyia umbratilis,L. monstruosa,L. ayrozai,L. anduzei,L. trichopyga,L. davisi,L. geniculata,L. georgii e L. saulensis.) were collected. Lutzomyia umbratilis showed the highest number of individuals (37.1%) of all species captured in the area. The phlebotomine productivity was estimated as 2.2 sandflies per 100 m²/day. September showed the highest density of individuals, with a productivity of 5.8.

This work had the objective of listing the sand fly species that occur in the State of Mato Grosso, Brazil. Data relating to entomological surveys conducted between 1996 and 2004 were obtained from the National Health Foundation and the State Health Department, and this was supplemented with information from research carried out in the state and from the specialized literature. There were records of 106 sand fly species belonging to the genus Lutzomyia. This is a rich and diversified fauna, with some species restricted to forested areas and others recorded throughout the state, independent of the vegetation type, and in areas modified by human action, with predominance of Lutzomyia whitmani.O presente trabalho teve como objetivo listar as espécies de flebotomíneos que ocorrem no Estado de Mato Grosso, Brasil. Os dados foram obtidos junto à Fundação Nacional de Saúde e à Secretaria Estadual de Saúde, referente às pesquisas entomológicas desenvolvidas entre 1996 e 2004, complementadas com informações de pesquisas desenvolvidas no Estado e bibliografia especializada. Foram registradas 106 espécies de flebotomíneos pertencentes ao gênero Lutzomyia. Esta é uma rica e diversificada fauna, com algumas espécies restritas a áreas florestais e outras registradas em todo o Estado, independente da formação vegetal e em áreas modificadas pela ação antrópica, com predominância de Lutzomyia whitmani.

Between March 2000 and December 2001 a survey of the sand flies (Diptera: Phlebotominae) of French Guiana was carried out during 14 nights of captures with CDC light-traps and Malaise traps, and resulted in the collection of 2245 individuals of 38 species. The most abundant species were Lutzomyia (Trichophoromyia) ininii Floch & Abonnenc, Lu.(Psychodopygus) squamiventris maripaensis Floch & Abonnenc, and Lu .(Nyssomyia) flaviscutellata Mangabeira. Half of the collected sand flies females were dissected under field conditions and five species were found harboring Leishmania-like parasites. The Leishmania (Kinetoplastidae: Trypanosomatidae) species were identified by molecular typing, and for the first time Lu. (Nys.) flaviscutellata was found harboring Leishmania (Viannia) guyanensis and Lu. (Tri) ininii harboring unknown Leishmania. The first record for French Guiana of Lu. (Psy.) squamiventris maripaensis harboring L. (V.) naiffi, was also reported. The patterns of diversification of the human cutaneous leishmaniasis transmission in French Guiana are discussed.

Na localidade do Brejo do Mutambal, situado no município de Varzelândia (MG), área endêmica para leishmaniose tegumentar, foram realizadas capturas mensais sistemáticas utilizando-se armadilhas luminosas do tipo CDC durante o período de janeiro a dezembro de 2000. Foram capturadas 19 espécies de flebotomíneos, totalizando 6.756 exemplares. Lutzomyia intermedia (5,1%), L. migonei (0,4%) e L. whitmani (0,1%), relacionadas com a transmissão de leishmaniose tegumentar, foram capturadas em número reduzido. Lutzomyia longipalpis foi a espécie predominante (34,8%), sugerindo também um risco de transmissão da leishmaniose visceral. A proporção de insetos capturados no peridomícilio foi de 91,7% enquanto no intradomicílio foi de 8,3%. A interferência de fatores climáticos (temperatura, umidade relativa do ar e pluviosidade) sobre a dinâmica populacional de flebotomíneos foi avaliada.Between January and December 2000, systematic monthly capture of phlebotomine sandflies was undertaken by means of light traps of CDC type in Brejo do Mutambal, an endemic area for American cutaneous leishmaniasis located in the municipality of Varzelândia, State of Minas Gerais. Nineteen phlebotomine species were captured, totaling 6,756 specimens. The species correlated with ACL transmission were captured in low numbers, as follows: Lutzomyia intermedia (5.1%), L. migonei (0.4%) and L. whitmani (0.1%). Lutzomyia longipalpis was the predominant species captured (34.8%), thus also suggesting a risk of visceral leishmaniasis transmission. The proportion of sandflies captured in areas surrounding homes was 91.7 % while 8.3% were captured inside homes. The interference of climatic factors (temperature, relative air humidity and rainfall) on phlebotomine population dynamics was evaluated.

El estudio de los insectos asociados a la epidemiología de la leishmaniasis, en la Costa Caribe colombiana, se ha concentrado en los departamentos de Sucre y Córdoba, por consiguiente existe un escaso conocimiento de la fauna de flebotomíneos del resto de la región. En la presente nota se presentan cuatro nuevos registros de Lutzomyia spp., para el departamento de Cesar. Los insectos fueron colectados con dos trampas de luz tipo CDC, equipadas con LED de color azul, en el Balneario Hurtado de la ciudad de Valledupar, Cesar. Se recolectaron en total 50 flebotomíneos, los cuales estuvieron representados por las especies Lutzomyia cayennensis cayennensis (38 %), L. evansi (28 %), L. trinidadensis (14 %), L. venezuelensis (10 %), L. micropyga (6 %) y L. rangeliana (2 %). Como primeros registros para el departamento sobresalen L. evansi, L. venezuelensis, L. micropyga y L. rangeliana, con lo que se eleva a ocho el número de especies reportadas hasta la fecha en el Cesar. Entre los nuevos registros se destaca el hallazgo de L. evansi, reconocido vector de Leishmania spp. en la Costa Caribe de Colombia.

Los insectos relacionados con la transmisión de los patógenos causantes de las leishmaniasis han sido poco estudiados en la Sierra Nevada de Santa Marta, Colombia, incluido el departamento de Magdalena, donde a la fecha están registradas trece especies del género Lutzomyia. En la presente nota se informa el hallazgo de tres especies y un subgénero adicionales en la región. Se recolectaron 885 flebotomíneos en Seywiaka y las veredas Las Tinajas y Calabazo, estribaciones de la Sierra Nevada de Santa Marta (117-130 m s.n.m.). El 84 % de los ejemplares se obtuvieron con trampa CDC, el 11 % con trampa Shannon y el 5 % fueron capturados, en reposo, con un dispositivo eléctrico de succión. Se identificaron nueve especies, Lu. gomezi, Lu. panamensis, Lu. trinidadensis, Lu. carpenteri, Lu. evansi, Lu. dysponeta, Lu. dubitans, Lu. shannoni, y Lu. micropyga, la más abundante fue Lu. gomezi (69 %), seguida por Lu. panamensis (14 %). También se recolectaron ejemplares de la serie Lu. osornoi del subgénero Helcocyrtomyia. Entre el material hallado sobresalen Lu. carpenteri, Lu. dubitans y Lu. dysponeta como primeros registros para el departamento del Magdalena, además de Lu. (Helcocyrtomyia) sp., que representa el primer informe del subgénero en el Caribe colombiano.

Introducción. Las especies de Lutzomyia del subgénero Sciopemyia poseen una distribución restringida y son poco frecuentes en las recolectas de flebotomíneos, con la excepción de Lutzomyia sordellii, que se encuentra desde Costa Rica hasta Argentina. Hasta la fecha sólo dos de estas especies se han hallado en Colombia, Lutzomyia sordellii y Lutzomyia preclara. Objetivo. El propósito de este artículo es redescribir la hembra de Lutzomyia vattierae, especie del subgénero Sciopemyia que se registra por primera vez en el territorio nacional. Materiales y métodos. El estudio se desarrolló en la serranía de La Macarena, departamento del Meta. Esta serranía se ubica entre la cuenca del Orinoco y del Amazonas, y es independiente de la cordillera de Los Andes. Los flebotomíneos se recolectaron durante dos noches consecutivas entre las 18:00 y 06:00 horas usando una trampa de luz tipo CDC instalada dentro de un bosque primario. Resultados. Se obtuvieron cuatro hembras del género Lutzomyia, las cuales fueron identificadas como L. vattierae, que se diferencia de L. preclara por la presencia de papila en el flagelómero III y de L. sordellii, por la forma y longitud de las espermatecas y de los ductos espermáticos individuales. Conclusión. El hallazgo de esta especie incrementa a tres el número de taxones del subgénero Sciopemyia registrados en Colombia, que ahora incluyen a L. sordellii, L. preclara y L. vattierae.

The distribution of sand flies and cases of tegumentary leishmaniasis in the area surrounding JB Alberd city, and the proximities of Catamarca province were studied, after an increase of reported cases from JB Alberdi, Tucumán province, in 2003. Of 14 confirmed cases, 57% were females and 57% were less than 15 years old, suggesting peridomestic transmission. However, 86% of them lived close to the Marapa river forest gallery and related wooded areas. Over 1,013 sand flies were collected; Lutzomyia neivai (Pinto, 1926) was prevalent at all the sites (92.3%), while Lutzomyia migonei (França, 1920) (6.7%) and Lu. cortelezzii (Brèthes, 1923) (1%) were also found. The spatial distribution of Lu. neivai overlapped that of the cases, with higher abundance in microfocal hot spots close to the river in stable vegetated habitats or modified habitats with shadow and animal blood sources. The cumulative outcome of anthropic, ecological and climatic factors could have contributed to the onset of the outbreak.Após um aumento nos casos notificados na cidade de JB Alberdi, Provincia de Tucumán, no ano de 2003, foram estudados a distribuição de flebotomíneos e casos de leishmaniose tegumentar nos arredores de JB Alberdi, e na área próxima à Província de Catamarca. De 14 casos confirmados, 57% foram mulheres e 57% tinham menos de 15 anos de idade, sugerindo transmissão peridomiciliar. Contudo, 86% dos casos residiam perto da galeria florestal do rio Marapa e perto de ilhas de vegetacão residual. De 1.013 flebotomíneos coletados, Lutzomyia neivai (Pinto, 1926) foi a espécie dominante em todos os sítios (92,3%). Também, se capturaram Lutzomyia migonei (França, 1920) (6,7%) e Lutzomyia cortelezzii (Brèthes, 1923) (1%). A distribuicão espacial de Lu. neivai se sobrepõe com a dos casos com alta abundância em pontos quentes microfocais próximos ao rio, em habitats estáveis com vegetação, ou habitats modificados com sombras e fonte de sangue animal. O efeito acumulativo de fatores antrópicos, ecológicos e climáticos pode ter contribuido à geração do surto epidêmico.

In this paper we review the natural history of pheromone communication and the current diversity of aggregation-sex pheromones in the sand fly Lutzomyia longipalpis. This species complex is the main vector of Leishmania infantum, the agent of visceral leishmaniasis in the Americas. The identification of variation in pheromone chemotypes combined with molecular and sound analyses have all contributed to our understanding of the extent of divergence among cryptic members of this complex. The importance of chemical signals as pre-mating barriers and drivers of speciation is discussed. Moreover, the importance of aggregation-sex pheromones as sexually selected signals is highlighted with evidence from the literature suggesting their potential role in species and mate recognition as well as mate assessment. The distinct evolutionary forces possibly involved are briefly reviewed and discussed in the context of this intriguing insect. [ABSTRACT FROM AUTHOR]

Background: Previous works showed that immunization with saliva from Lutzomyia intermedia, a vector of Leishmania braziliensis, does not protect against experimental infection. However, L. braziliensis is also transmitted by Lutzomyia whitmani, a sand fly species closely related to Lu. intermedia. Herein we describe the immune response following immunization with Lu. whitmani saliva and the outcome of this response after L. braziliensis infection. Methods and findings: BALB/c mice immunized with Lu. whitmani saliva developed robust humoral and cellular immune responses, the latter characterized by an intense cellular infiltrate and production of IFN-γ and IL-10, by both CD4+ and CD8+ cells. Mice immunized as above and challenged with L. braziliensis plus Lu. whitmani saliva displayed significantly smaller lesions and parasite load at the challenge site. This protection was associated with a higher (p<0.05) IFN-γ production in response to SLA stimulation. Long-term persisting immunity was also detected in mice immunized with Lu. whitmani saliva. Furthermore, individuals residing in an endemic area for cutaneous leishmaniasis (CL) presented antibody responses to Lu. whitmani saliva. However CL patients, with active lesions, displayed a lower humoral response to Lu. whitmani saliva compared to individuals with subclinical Leishmania infection. Conclusion: Pre-exposure to Lu. whitmani saliva induces protection against L. braziliensis in a murine model. We also show that Lu. whitmani salivary proteins are immunogenic in naturally exposed individuals. Our results reinforce the importance of investigating the immunomodulatory effect of saliva from different species of closely related sand flies. [ABSTRACT FROM AUTHOR]

Cutaneous leishmaniasis (CL) is caused by a protozoan of the genus Leishmania and is transmitted by sand flies. The state of Espírito Santo (ES), an endemic area in southeast Brazil, has shown a considerably high prevalence in recent decades. Environmental niche modelling (ENM) is a useful tool for predicting potential disease risk. In this study, ENM was applied to sand fly species and CL cases in ES to identify the principal vector and risk areas of the disease. Sand flies were collected in 466 rural localities between 1997 and 2013 using active and passive capture. Insects were identified to the species level, and the localities were georeferenced. Twenty-one bioclimatic variables were selected from WorldClim. Maxent was used to construct models projecting the potential distribution for five Lutzomyia species and CL cases. ENMTools was used to overlap the species and the CL case models. The Kruskal–Wallis test was performed, adopting a 5% significance level. Approximately 250,000 specimens were captured, belonging to 43 species. The area under the curve (AUC) was considered acceptable for all models. The slope was considered relevant to the construction of the models for all the species identified. The overlay test identified Lutzomyia intermedia as the main vector of CL in southeast Brazil. ENM tools enable an analysis of the association among environmental variables, vector distributions and CL cases, which can be used to support epidemiologic and entomological vigilance actions to control the expansion of CL in vulnerable areas. [ABSTRACT FROM AUTHOR]

Background: The geographic scale and degree of genetic differentiation for arthropod vectors that transmit parasites play an important role in the distribution, prevalence and coevolution of pathogens of human and wildlife significance. We determined the genetic diversity and population structure of the sand fly Lutzomyia vexator over spatial scales from 0.56 to 3.79 km at a study region in northern California. The study was provoked by observations of differentiation at fine spatial scales of a lizard malaria parasite vectored by Lu. vexator. Methods: A microsatellite enrichment/next-generation sequencing protocol was used to identify variable microsatellite loci within the genome of Lu. vexator. Alleles present at these loci were examined in four populations of Lu. vexator in Hopland, CA. Population differentiation was assessed using Fst and D (of Cavalli-Sforza and Edwards), and the program Structure was used to determine the degree of subdivision present. The effective population size for the sand fly populations was also calculated. Results: Eight microsatellite markers were characterized and revealed high genetic diversity (uHe = 0.79-0.92, Na = 12-24) and slight but significant differentiation across the fine spatial scale examined (average pairwise D = 0.327; FST = 0.0185 (95 % bootstrapped CI: 0.0102-0.0264). Even though the insects are difficult to capture using standard methods, the estimated population size was thousands per local site. Conclusions: The results argue that Lu. vexator at the study sites are abundant and not highly mobile, which may influence the overall transmission dynamics of the lizard malaria parasite, Plasmodium mexicanum, and other parasites transmitted by this species. [ABSTRACT FROM AUTHOR]

Background: Lutzomyia evansi, a phlebotomine insect endemic to Colombia's Caribbean coast, is considered to be the main vector of visceral and cutaneous leishmaniasis in the region. Although insects of this species can harbor pathogenic and non-pathogenic microorganisms in their intestinal microbiota, there is little information available about the diversity of gut bacteria present in Lutzomyia evansi. In this study, conventional microbiological methods and molecular tools were used to assess the composition of bacterial communities associated with Lutzomyia evansi guts in immature and adult stages of natural populations from the department of Sucre (Caribbean coast of Colombia). Methods: Sand flies were collected from two locations (peri-urban and jungle biotype) in the Department of Sucre (Caribbean coast of Colombia). A total of 752 Lutzomyia evansi intestines were dissected. In this study, 125 bacterial strains were isolated from different culture media (LB Agar, MacConkey Agar). Different methods were used for bacterial identification, including ribosomal intergenic spacer analysis (RISA) and analysis of the 16S rRNA and gyrB gene sequences. The genetic profiles of the bacterial populations were generated and temporal temperature gradient gel electrophoresis (TTGE) was used to compare them with total gut DNA. We also used PCR and DNA sequence analysis to determine the presence of Wolbachia endosymbiont bacteria and Leishmania parasites. Results: The culture-dependent technique showed that the dominant intestinal bacteria isolated belong to Acinetobacter, Enterobacter, Pseudomonas, Ochrobactrum, Shinella and Paenibacillus in the larval stage; Lysobacter, Microbacterium, Streptomyces, Bacillus and Rummeliibacillus in the pupal stage; and Staphylococcus, Streptomyces, Brevibacterium, Acinetobacter, Enterobacter and Pantoea in the adult stage. Statistical analysis revealed significant differences between the fingerprint patterns of the PCR-TTGE bands in bacterial communities from immature and adult stages. Additionally, differences were found in bacterial community structure in fed females, unfed females, males and larvae. The intestinal bacteria detected by PCR-TTGE were Enterobacter cloacae and Bacillus thuringiensis, which were present in different life stages of Lu. evansi, and Burkholderia cenocepacia and Bacillus gibsonii, which were detected only in the larval stage. Wolbachia and Leishmania were not detected in gut samples of Lutzomyia evansi. Conclusions: The analyses conducted using microbiological and molecular approaches indicated significant variations in the bacterial communities associated with the gut of Lu. evansi, depending on the developmental stage and food source. We propose that these elements affect microbial diversity in L. evansi guts and may in turn influence pathogen transmission to humans bitten by this insect. [ABSTRACT FROM AUTHOR]

Background: Visceral leishmaniasis (VL) is a disease caused by two known vector-borne parasite species (Leishmania donovani, L. infantum), transmitted to man by phlebotomine sand flies (species: Phlebotomus and Lutzomyia), resulting in ≈50,000 human fatalities annually, ≈67% occurring on the Indian subcontinent. Indoor residual spraying is the current method of sand fly control in India, but alternative means of vector control, such as the treatment of livestock with systemic insecticide-based drugs, are being evaluated. We describe an individual-based, stochastic, life-stage-structured model that represents a sand fly vector population within a village in India and simulates the effects of vector control via fipronil-based drugs orally administered to cattle, which target both blood-feeding adults and larvae that feed on host feces. Principle findings: Simulation results indicated efficacy of fipronil-based control schemes in reducing sand fly abundance depended on timing of drug applications relative to seasonality of the sand fly life cycle. Taking into account cost-effectiveness and logistical feasibility, two of the most efficacious treatment schemes reduced population peaks occurring from April through August by ≈90% (applications 3 times per year at 2-month intervals initiated in March) and >95% (applications 6 times per year at 2-month intervals initiated in January) relative to no control, with the cumulative number of sand fly days occurring April-August reduced by ≈83% and ≈97%, respectively, and more specifically during the summer months of peak human exposure (June-August) by ≈85% and ≈97%, respectively. Conclusions: Our model should prove useful in a priori evaluation of the efficacy of fipronil-based drugs in controlling leishmaniasis on the Indian subcontinent and beyond. [ABSTRACT FROM AUTHOR]

The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly. [ABSTRACT FROM AUTHOR]

Background: Leishmania parasites are transmitted by phlebotomine sand flies and a crucial step in their life-cycle is the binding to the sand fly midgut. Laboratory studies on sand fly competence to Leishmania parasites suggest that the sand flies fall into two groups: several species are termed "specific/restricted" vectors that support the development of one Leishmania species only, while the others belong to so-called "permissive" vectors susceptible to a wide range of Leishmania species. In a previous study we revealed a correlation between specificity vs permissivity of the vector and glycosylation of its midgut proteins. Lutzomyia longipalpis and other four permissive species tested possessed O-linked glycoproteins whereas none were detected in three specific vectors examined. Results: We used a combination of biochemical, molecular and parasitological approaches to characterize biochemical and biological properties of O-linked glycoprotein of Lu. longipalpis. Lectin blotting and mass spectrometry revealed that this molecule with an apparent molecular weight about 45-50 kDa corresponds to a putative 19 kDa protein with unknown function detected in a midgut cDNA library of Lu. longipalpis. We produced a recombinant glycoprotein rLuloG with molecular weight around 45 kDa. Anti-rLuloG antibodies localize the native glycoprotein on epithelial midgut surface of Lu. longipalpis. Although we could not prove involvement of LuloG in Leishmania attachment by blocking the native protein with anti-rLuloG during sand fly infections, we demonstrated strong binding of rLuloG to whole surface of Leishmania promastigotes. Conclusions: We characterized a novel O-glycoprotein from sand fly Lutzomyia longipalpis. It has mucin-like properties and is localized on the luminal side of the midgut epithelium. Recombinant form of the protein binds to Leishmania parasites in vitro. We propose a role of this molecule in Leishmania attachment to sand fly midgut. [ABSTRACT FROM AUTHOR]

Identification of the species of phlebotomine sand flies present in each focus of leishmaniasis is necessary to incriminate vectors and implement vector control strategies. Although the cytochrome oxidase I (COI) gene has been proposed as a barcode for the identification of animal species, less than 20% of New World phlebotomines have been characterized to date. In this study DNA barcoding was used to identify phlebotomine species of the mixed leishmaniasis focus in the Colombian Caribbean by means of three evolutionary models: Kimura’s two parameter (K2P) nucleotide substitution model, that of ( Tamura and Nei, 1993 ) (TN93) and proportional sequence divergence ( p -distances). A 681 bp sequence of the COI gene was obtained from 66 individuals belonging to 19 species of the genus Lutzomyia ( Lu. abonnenci , Lu. atroclavata , Lu. bicolor , Lu. carpenteri , Lu. cayennensis cayennensis , Lu. dubitans , Lu. evansi , Lu. gomezi , Lu. gorbitzi, Lu. longipalpis , Lu. micropyga, Lu. migonei , Lu. panamensis , Lu. ( Psathyromyia ) sp., Lu. rangeliana , Lu. serrana , Lu. shannoni , Lu. trinidadensis and Lu. venezuelensis ) and one of Brumptomyia ( B. mesai ). The genetic divergence values for TN93 among individuals of the same species fluctuated up to 3.2% (vs. 2.9% for K2P and 2.8% for p -distances), while the values between species ranged from 8.8–43.7% (vs. 6.8–19.6% for K2P and 6.6–17.4% for p -distances). A dendrogram constructed by means of the Neighbor-Joining method grouped phlebotomines into 20 clusters according to species, with bootstrap values of up to 100% in those with more than one individual. However, loss of the phylogenetic signal of the gene COI was observed at the supraspecific level as a consequence of substitutional saturation. In conclusion, irrespective of the evolutionary model selected, all phlebotomines were correctly assigned to species, showing 100% concordance with morphological identification. [ABSTRACT FROM AUTHOR]

Background: Lutzomyia longipalpis is the main vector of visceral leishmaniasis in Latin America. Sandfly immune responses are poorly understood. In previous work we showed that these vector insects respond to bacterial infections by modulating a defensin gene expression and activate the Imd pathway in response to Leishmania infection. Aspects of innate immune pathways in insects (including mosquito vectors of human diseases) have been revealed by studying insect cell lines, and we have previously demonstrated antiviral responses in the L. longipalpis embryonic cell line LL5. Methods: The expression patterns of antimicrobial peptides (AMPs) and transcription factors were evaluated after silencing the repressors of the Toll pathway (cactus) and Imd pathway (caspar). AMPs and transcription factor expression patterns were also evaluated after challenge with heat-killed bacteria, heat-killed yeast, or live Leishmania. Results: These studies showed that LL5 cells have active Toll and Imd pathways, since they displayed an increased expression of AMP genes following silencing of the repressors cactus and caspar, respectively. These pathways were also activated by challenges with bacteria, yeast and Leishmania infantum chagasi. Conclusions: We demonstrated that L. longipalpis LL5 embryonic cells respond to immune stimuli and are therefore a good model to study the immunological pathways of this important vector of leishmaniasis. [ABSTRACT FROM AUTHOR]

Background: Sand flies are insect vectors of protozoa from the genus Leishmania, causative parasites of visceral and American tegumentary leishmaniases. The present study discusses the bioecological aspects of sand fly species, transmitters of Leishmania protozoa, in different ecotopes of an Atlantic Forest Conservation Unit located in the metropolitan region of Natal, Rio Grande do Norte state, Brazil. Methods: Two monthly captures were made in 1 year, using CDC light traps, in two anthropized and two preserved environments. Results: A total of 2936 sand flies belonging to the following ten species were captured: Evandromyia walkeri, Evandromyia evandroi, Psychodopygus wellcomei, Sciopemyia sordellii, Psathyromyia brasiliensis, Lutzomyia longipalpis, Evandromyia lenti, Psathyromyia shannoni, Nyssomyia whitmani and Nyssomyia intermedia. The most common species was E. walkeri (77.6 %), followed by E. evandroi (17.5 %). Forest was the site with the greatest abundance (32.4 %), followed by bamboo grove (26.3 %). Conclusions: Sand flies were generally more abundant in the rainy season and L. longipalpis, a vector species of Leishmania infantum, was adapted to anthropized environments. It was confirmed that P. wellcomei, a vector of Leishmania braziliensis in Amazônia, is a species associated with more preserved environments, and occurs only in the rainy season. [ABSTRACT FROM AUTHOR]

In South America, cutaneous leishmaniasis is the most frequent clinical form of leishmaniasis. Bolivia is one of the countries with higher incidence, with 33 cases per 100,000 individuals, and the disease is endemic in 70% of the territory. In the last decade, the number of cases has increased, the age range has expanded, affecting children under 5 years old, and a similar frequency between men and women is found. An entomological study with CDC light traps was conducted in three localities (Chipiriri, Santa Elena and Pedro Domingo Murillo) of the municipality of Villa Tunari, one of the main towns in the Chapare province (Department of Cochabamba, Bolivia). A total of 16 specimens belonging to 6 species of the genus Lutzomyia were captured: Lu. aragaoi , Lu. andersoni , Lu. antunesi , Lu. shawi , Lu. yuilli yuilli and Lu. auraensis . Our results showed the presence of two incriminated vectors of leishmaniasis in an urbanized area and in the intradomicile. More entomological studies are required in the Chapare province to confirm the role of vector sand flies, the intradomiciliary transmission of the disease and the presence of autochthonous cases of cutaneous leishmaniasis. [ABSTRACT FROM AUTHOR]

In South America, Lutzomyia umbratilis is the main vector of Leishmania guyanensis , one of the species involved in the transmission of American tegumentary leishmaniasis. In Brazil, L. umbratilis has been recorded in the Amazon region, and an isolated population has been identified in the state of Pernambuco, Northeastern region. This study assessed the phylogeographic structure of three allopatric Brazilian populations of L. umbratilis . Samples of L. umbratilis were collected from Rio Preto da Eva (north of the Amazon River, Amazonas), from Manacapuru (south of the Amazon River), and from the isolated population in Recife, Pernambuco state. These samples were processed to obtain sequences of the period gene. Phylogenetic analysis revealed the presence of two distinct monophyletic clades: one clade comprised of the Recife and Rio Preto da Eva samples, and one clade comprised of the Manacapuru samples. Comparing the Manacapuru population with the Recife and Rio Preto da Eva populations revealed high indices of interpopulational divergence. Phylogenetic analysis indicated that geographical distance and environmental differences have not modified the ancestral relationship shared by the Recife and Rio Preto da Eva populations. Genetic similarities suggest that, in evolutionary terms, these populations are more closely related to each other than to the Manacapuru population. These results confirm the existence of an L. umbratilis species complex composed of at least two incipient species. [ABSTRACT FROM AUTHOR]

Background: Since 1996, there are emerging autochthonous cases of leishmaniasis in Thailand due to Leishmania "siamensis" and to L. martiniquensis explaining a recent interest for the sand fly fauna where Sergentomyia gemmea and Se. barraudi have been considered possible vectors in the country. Methods: Field studies were undertaken in a cave of Phitsanulok Province, Thailand. Phlebotomine sandflies have been studied morphologically and some have been processed for molecular biology (sequencing of cytB rDNA). Results: A new species of sand fly, belonging to the genus Sergentomyia: Se. phadangensis n. sp., is described. The association of the male and female is supported by the homology of the sequences of cytochrome b rDNA. Conclusions: The description of a new species in Thailand is of importance in view of the existence of autochthonous leishmaniases. [ABSTRACT FROM AUTHOR]

Identification of the bloodmeal sources of phlebotomine sand flies is fundamental to determining which species are anthropophilic and understanding the transmission of Leishmania parasites in natural epidemiological settings. The objective of this study was to identify sand fly bloodmeals in the mixed leishmaniasis focus of the department of Sucre, northern Colombia. In all 141 engorged female sand flies were analyzed, after being captured in intradomiciliary, peridomiciliary and extradomiciliary habitats with Shannon and CDC traps and by active searching in diurnal resting sites. Bloodmeals were identified by sequencing and analysis of a 358 bp fragment of the mitochondrial gene Cytochrome b (CYB) and a 330 bp fragment of the nuclear gene prepronociceptin (PNOC). Using both genes 105 vertebrate bloodmeals were identified, with an efficiency of 72% for CYB but only 7% for PNOC. Ten species of vertebrates were identified as providing bloodmeal sources for 8 sand fly species: Homo sapiens ( Lutzomyia evansi, L utzomyia panamensis, L utzomyia micropyga, L utzomyia shannoni and L utzomyia atroclavata ), Equus caballus ( L. evansi, L. panamensis and L utzomyia cayennensis cayennensis ), Equus asinus ( L. evansi and L. panamensis ), Bos taurus ( L. evansi, L. panamensis and L. c. cayennensis ), Tamandua mexicana ( L. shannoni and L utzomyia trinidadensis ), Proechimys guyanensis ( L. evansi, L. panamensis and L. c. cayennensis ), Mabuya sp. ( L utzomyia micropyga ), Anolis sp. ( L. micropyga ), Sus scrofa ( L. evansi and L utzomyia gomezi ) and Gallus gallus ( L. evansi ). Cattle, donkeys, humans and pigs were significantly more important than other animals ( P = 0.0001) as hosts of L. evansi , this being the most abundant sand fly species. The five Lutzomyia species in which blood samples of human origin were detected included L. micropyga and L. atroclavata , constituting the first evidence of anthropophily in both species. [ABSTRACT FROM AUTHOR]

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No período de novembro de 2000 a novembro de 2001, foi realizado o estudo dos flebotomíneos nos municípios de Alto Caparaó e Caparaó, com o objetivo de determinar a sua variação sazonal, comparar os pontos de estudo quanto à ocorrência destes insetos e determinar os ambientes de prevalência destes. Foram realizadas coletas mensais, com armadilhas luminosas de Falcão em nove pontos, sendo quatro armadilhas por ponto, nos seguintes ambientes: abrigo de animais, mata, cafezal e parede externa das casas. Lutzomyia intermedia (Lutz & Neiva, 1912) foi a espécie predominante, e o abrigo de animais o ambiente com maior ocorrência de flebotomíneos. Encontrou-se diferença significativa na composição de espécies de flebotomíneos nos pontos estudados. Lutzomyia intermedia é a espécie suspeita de transmitir a Leishmania na região.In the period from November of 2000 to November of 2001, a study of sand flies was realized in the municipalities of Alto Caparaó and Caparaó with the objective of determining their seasonal variation, comparing the points of study related to the occurrence of these insects and detecting their ideal environments. Monthly collections were carried out, with Falcão light traps at nine points, four traps per point, in the following environments: of animals shelter, forest (bush), coffee plantation and the external walls of houses. Lutzomyia intermedia (Lutz & Neiva, 1912) was the predominant species, and animal shelter the environment with the largest occurrence of sand flies. A significant difference in the composition of sand fly species was found in the studied points. Lutzomyia intermedia is the species suspected of transmitting Leishmania in the region.

No período de novembro de 2000 a novembro de 2001, foi realizado o estudo dos flebotomíneos nos municípios de Alto Caparaó e Caparaó, com o objetivo de determinar a sua variação sazonal, comparar os pontos de estudo quanto à ocorrência destes insetos e determinar os ambientes de prevalência destes. Foram realizadas coletas mensais, com armadilhas luminosas de Falcão em nove pontos, sendo quatro armadilhas por ponto, nos seguintes ambientes: abrigo de animais, mata, cafezal e parede externa das casas. Lutzomyia intermedia (Lutz & Neiva, 1912) foi a espécie predominante, e o abrigo de animais o ambiente com maior ocorrência de flebotomíneos. Encontrou-se diferença significativa na composição de espécies de flebotomíneos nos pontos estudados. Lutzomyia intermedia é a espécie suspeita de transmitir a Leishmania na região.

A flutuação sazonal, a freqüência horária e a ocorrência dos flebotomíneos nos ambientes intradomiciliar, peridomiciliar e extradomiciliar (cerrado), no município de Santa Quitéria, Estado do Maranhão foram estudados. Os espécimes foram capturados entre 18 e 6 horas, de maio de 1999 a abril de 2000, com armadilhas luminosas tipo CDC. Foram coletados 4.880 espécimes de 11 espécies. A riqueza e abundância foram maiores no peridomicílio (11 espécies; 50,1% dos espécimes), seguido pelo intradomicílio (9 espécies, 34%) e cerrado (7 espécies, 15,8%). Duas espécies foram encontradas na estação chuvosa, uma na estiagem e oito em ambas estações. Na estiagem foram registradas elevadas freqüências de Lutzomyia longipalpis Lutz & Neiva, 1912 (88,4%), L. evandroi Costa Lima & Antunes, 1936 (83,6%), L. lenti Mangabeira, 1938 (86%) e L. shannoni Dyar, 1929 (100%), enquanto as freqüências de L. quinquefer Dyar, 1929 (100%) e L. whitmani Antunes & Coutinho, 1939 (75%) foram maiores no período chuvoso. Os flebotomíneos foram encontrados a noite inteira, mas os horários de maior freqüência variaram de acordo com a espécie, observando-se picos no crepúsculo vespertino e primeiras horas da noite: L. quinquefer (18 h - 19 h); L. goiana Martins, Falcão & Silva, 1962 (18 h - 21 h); L. whitmani (19 h - 21 h) e L. longipalpis (20 h - 21 h) e ao longo da noite e no crepúsculo matutino: L. evandroi (21 h - 23 h e 3 h - 5 h), L. longipalpis (1 h - 3 h), L. lenti (22 h - 23 h e 4 h - 5 h). A ocorrência dos flebotomíneos nos diferentes ambientes, horários e estações vem sendo acompanhada por notificações de vários casos de leishmanioses cutânea e visceral.The seasonal fluctuation, hourly frequency and occurrence of phlebotomine sandflies inside and around dwellings and in the cerrado area of the municipality of Santa Quitéria, State of Maranhão were studied. The specimens were collected between 6:00 pm and 6:00 am from May 1999 to April 2000 through CDC-type light traps. A total of 4,880 specimens belonging to 11 species were collected. The highest species richness and abundance were observed around dwellings (11 species, 50.1% of the specimens), followed by species collected inside dwellings (9 species, 34%) and in the cerrado (7 species, 15.8%). Two species were found during the rainy season, one during the dry season and eight during both seasons. High frequencies of Lutzomyia longipalpis Lutz & Neiva, 1912 (88.4%), L. evandroi Costa Lima & Antunes, 1936 (83.6%), L. lenti Mangabeira, 1938 (86%), and L. shannoni Dyar, 1929 (100%) were recorded during the dry season, whereas the frequencies of L. quinquefer Dyar, 1929 (100%) and L. whitmani Antunes & Coutinho, 1939 (75%) were higher during the rainy period. Phlebotomine sandflies were collected throughout the night, but the times of higher frequency varied according to species, with peaks being observed for L. quinquefer (6:00 - 7:00 pm), L. goiana Martins, Falcão & Silva, 1962 (6:00 - 9:00 pm), L. whitmani (7:00 - 9:00 pm), and L. longipalpis (8:00 - 9:00 pm) during sunset and in the first night hours, and for L. evandroi (9:00 - 11:00 pm and 3:00 - 5:00 am), L. longipalpis (1:00 - 3:00 am), and L. lenti (10:00 - 11:00 pm and 4:00 - 5:00 am) throughout the night and during dawn. The occurrence of phlebotomine sandflies in different environments, at different times and during different seasons is accompanied by the notification of severed cases of cutaneous and visceral leishmaniasis.

Lutzomyia cruciata Coquillet (Diptera: Psychodidae: Phlebotominae) is a potential vector of Leishmania sp.; its geographical distribution in Mexico is widespread, but its life history is unknown. The present study gives relevant information on the life cycle, morphology, survival and reproduction of Lu. cruciata observed over successive generations under laboratory conditions. Seven successive generations were produced. A total of 975 adults were obtained in a sexual proportion of 1.1 : 1 (female : male). Each Lu. cruciata female produced 20.7 eggs and 1.9 adults, approximately, with a proportion of eggs per female of 2.7% (first generation) and 21.3% (second generation). The life cycle of Lu. cruciata, from egg to adult, occurred in 52.7 ± 0.52 days. The largest percentage of mortality occurred during the egg stage (48.5%) and the first larval instar (26.5%), whereas in the pupal stage mortality was the lowest (9.1%). Lutzomyia cruciata exhibits sexual dimorphism based on size, which is exhibited as of the second larval instar, males being smaller than females. The maximum survival of females and males was 10 and 15 days, respectively. An overview of the immature stages of the species made with an electronic scanning microscope is included. This paper contributes basic information on aspects of Lu. cruciata that were previously unknown related to its life history. [ABSTRACT FROM AUTHOR]

Phlebotomine sandflies, vectors of Leishmania (Kinetoplastida: Trypanosomatidae) parasites that affect millions of people worldwide, breed in terrestrial biotopes. As immature stages are rarely accessible, the detection of their natural breeding sites is primarily based on findings of juvenile males with unrotated external genitalia. In males, permanent 180° rotation on the longitudinal body axis occurs soon after eclosion; however, no study has as yet addressed this aspect in detail. The present study describes the timing and duration of the rotation of male external genitalia in eight highly medically important sandfly species belonging to the genera Sergentomyia, Lutzomyia and Phlebotomus (all: Diptera: Psychodidae), kept under controlled laboratory conditions. The average duration of rotation was species-specific and varied from 12 h in Sergentomyia schwetzi to 33 h in Phlebotomus sergenti. Significant differences in rotation times were found among species, even between two closely related species of the subgenus Larroussius, Phlebotomus orientalis and Phlebotomus tobbi. The rotation of genitalia in all three studied genera was randomly oriented and similar numbers of clockwise and counter-clockwise events were observed. The study also addresses the effects of some external factors. In all species studied, rotation was not affected by the time of day of eclosion. Similarly, no differences in total rotation time were found between Phlebotomus papatasi males maintained at 25 and 20 °C, respectively. The present findings will assist in the search for natural breeding sites and in studies aimed at elucidating strategies for integrated sandfly and leishmaniasis control. [ABSTRACT FROM AUTHOR]

Lutzomyia spinicrassa is a vector of Leishmaniabraziliensis. This sand fly has a broadgeographical distribution in Colombia and Venezuelaand it’s founded mainly in coffeeplantations. Methodology: Starting from 600females of L. spinicrassa captured in field alaboratory colony was established. The developmenttime from egg to adult ranged from 58 to78 days, 11 weeks in average. Population parametersof five successive generations maintainedin groups were compared with a generationreared individually. Results: The followingparameters were obtained in each experimentalcondition: net rate of reproduction (6.92 and 7females per female per generation), intrinsic rate of population increment (0.17 and 0.18 females perfemale per week) and finite rate of populationincrement (1.06 and 1.19 individuals per femaleper week). Conclusion: These data suggest thatthe colony of L. spinicrassa had a constant incrementduring the six analyzed generations.

O comportamento e hábitos alimentares de algumas espécies da flebotomíneos têm sido útil na compreensão da epidemiologia das leishmanioses. No município de Porteirinha (MG), foram realizadas capturas mensais sistematizadas utilizando-se 28 armadilhas luminosas tipo CDC, durante o período de janeiro a dezembro de 2002. Foram capturadas 14 espécies de flebotomíneos, totalizando 1.408 exemplares. De acordo com o ambiente, os resultados obtidos mostraram que o peridomicílio apresentou a maior (53,3%) porcentagem dos espécimens encontrados na região, embora parte (46,7%) da fauna também tenha sido encontrada no intradomicílio. O repasto sanguíneo de 38 fêmeas de Lutzomyia longipalpis, provenientes do campo, foi identificado através da reação de precipitina. Os resultados indicam que Lutzomyia longipalpis foi a espécie predominante (65,1%), mostrando-se oportunista, podendo sugar uma ampla variedade de vertebrados.Studies on the behavioral and feeding habits of some species of phlebotominae sand flies have contributed to the comprehension of the epidemiology of leishmaniasis. In the present work, systematic captures were performed monthly in the municipality of Porteirinha (MG) using 28 light traps (CDC) from January to December 2002. Fourteen different species of phlebotomine were captured in a total of 1,408 specimens. The highest percentage of individuals (53.3%) was collected in the peridomicile against 46.7% in the intradomicile. Lutzomyia longipalpis was the predominant species in that region. The blood feeding of 38 females of this species from the field was analyzed by precipitin reaction. The results indicated that Lutzomyia longipalpis is an opportunist (65.1%) species that feeds on a wide variety of vertebrates in nature.

lntroducción. En leishmaniasis se acepta que la reacción en cadena de la polimerasa (PCR) ha simplificado el proceso de incriminación vectorial. Sin embargo, pocas veces se ha determinado la sensibilidad y la especificidad de cada PCR en la detección y la identificación del parasito en los flebótomos. Objetivo. Evaluar la aplicabilidad de la reacción en cadena de la polimerasa (PCR), basada en los iniciadores 81 y 82, en la detecci6n e identificación de parasitos de Leishmania (Viannia) en insectos vectores enteros sin disecar. Metodología. Se determinó la sensibilidad y la especificidad de la PCR empleando diluciones de cultivo de parasitos de Leishmania spp. Se estableció el número máximo de hembras de Lutzomyia que pueden ser procesadas a la vez sin disminuir la sensibilidad de la PCR, procesando el ADN de grupos de una a cinco hembras de Lutzomyia en presencia del ADN de las diluciones de cultivo de parasitos. Además, se comparó en grupos de flebótomos infectados experimentalmente, la sensibilidad de esta PCR en la detección de infección por Leishmania (Viannia) frente al método de busqueda de flagelados por disección del insecto y examen microscópico. Resultados. La PCR detectó desde un parasito de Leishmania (Viannia) y permiti6 el procesamiento de hasta tres insectos enteros sin alterar la sensibilidad. Los porcentajes de infección experimental detectados con las dos tecnicas fueron similares, 33,3% con la PCR y 30% con el examen microscópico. Además, se confirmó que los iniciadores 81 y 82 son especificos para especies del subgenero Leishmania (Viannia). Conclusión. Los resultados obtenidos demuestran la sensibilidad y la especificidad de esta PCR y permiten recomendar su uso en la determinaci6n de infección natural con parasitos de Leishmania (Viannia) en poblaciones silvestres de flebótomos.

Precipitin tests were performed on blood meals of 199 sand flies (161 Lutzomyia umbratilis, 34 L. spathotrichia, two Lutzomyia of group shannoni, one L. anduzei) in a non-flooded upland forest on the Campus of the Universidade Federal do Amazonas. This is the second largest forest fragment in an urban setting in Brazil. Results on L. umbratilis, which is considered to be the principal leishmaniasis vector in this region, indicated rodents as its predominant blood source in contrast to previous reports in which blood meal analysis indicated that this species fed principally on Xenarthra (particularly sloths)

An important aspect of tropical medicine is analysis of geographic aspects of risk of disease transmission, which for lack of detailed public health data must often be reduced to an understanding of the distributions of critical species such as vectors and reservoirs. We examine the applicability of a new technique, ecological niche modeling, to the challenge of understanding distributions of such species based on municipalities in the state of São Paulo in which a group of 5 Lutzomyia sandfly species have been recorded. The technique, when tested based on independent occurrence data, yielded highly significant predictions of species' distributions; minimum sample sizes for effective predictions were around 40 municipalities.Um aspecto importante da medicina tropical é a análise de aspectos geográficos relacionados com o risco de transmissão de doenças. Devido à ausência de dados detalhados de saúde pública, estas análises são freqüentemente reduzidas à compreensão da distribuição de espécies críticas como vetores e reservatórios. Neste trabalho, é examinada a aplicabilidade de uma nova técnica, a modelagem de nicho ecológico, no estudo da distribuição destas espécies nos municípios do Estado de São Paulo, onde um grupo de 5 mosquitos do gênero Lutzomyia foi encontrado. A técnica foi testada em conjuntos de dados independentes, resultando em previsões altamente significativas; a amostragem mínima para se obter previsões eficazes foi de cerca de 40 municípios.

A new sex-aggregation pheromone, sobralene, produced by the sand fly Lutzomyia longipalpis from Sobral (Ceará State, Brazil) is shown to have the novel 6,12-membered ring-fused diterpene structure 3. It is proposed that sobralene is a likely shunt metabolite of the taxadiene synthase-catalysed cyclisation of geranygeranyl diphosphate. [ABSTRACT FROM AUTHOR]

La incriminación de especies de Lutzomyia del grupo verrucarum Theodor, 1965, en la transmisión de leishmaniosis en Colombia ha puesto de manifiesto la necesidad de conocer en detalle su distribución geográfica. Este trabajo pretende contribuir a su conocimiento mediante la incorporación de 34 registros nuevos, entre los que sobresalen el hallazgo de Lutzomyia spinicrassa en un bosque seco tropical de la Costa Atlántica, la presencia de Lutzomyia ovallesi en la Orinoquia y Amazonia y la simpatría de L. spinicrassa y Lutzomyia quasitownsendi en la Cordillera Oriental. Complementariamente, este artículo recopila y sintetiza la distribución municipal y altitudinal de las 19 especies registradas en el país. Los datos compilados muestran que la serie townsendi (L. spinicrassa, Lutzomyia longiflocosa, L. quasitownsendi, Lutzomyia sauroida, Lutzomyia torvida, Lutzomyia townsendi, Lutzomyia youngi) está generalmente asociada con los pisos altitudinales premontano y montano bajo, mientras la serie verrucarum hace presencia desde el piso tropical hasta el montano con taxones de extenso ámbito geográfico (Lutzomyia evansi, Lutzomyia columbiana, L. ovallesi, Lutzomyia nuneztovari, Lutzomyia nevesi) y taxones de distribución endémica (Lutzomyia andina, Lutzomyia disiuncta, Lutzomyia moralesi, Lutzomyia antioquiensis). De otro lado, los representantes de la serie pia (Lutzomyia pia, Lutzomyia limafalcaoae) y de la serie serrana (Lutzomyia serrana) aparecen desde el piso tropical hasta el montano bajo. Se postula que las divergencias en los rangos altitudinales podrían estar relacionadas intrínsecamente con el origen de las especies, derivándose de fenómenos climáticos y geológicos que han afectado la flora y fauna de la región andina.

Se evaluó la efectividad de la PCR como herramienta en la detección de la transmisión experimental de Leishmania chagasi a hámster, Mesocricetus auratus, por picadura del insecto vector. Dos pares de hámsteres sanos y anestesiados fueron colocados en jaulas que contenían hembras de Lutzomyia longipalpis. Previamente, las hembras se infectaron experimentalmente con Leishmania chagasi y la infección se confirmó por disección en una submuestra. A los 37 y 51 días después de la exposición a los insectos infectados, las biopsias de hígado y bazo de cada hámster se sometieron a examen directo al microscopio, histopatología y PCR. El ADN se extrajo con Chelex 100®; en la amplificación se utilizó un par de iniciadores específicos para la región conservada de los minicírculos del ADN de Leishmania. El producto amplificado se separó en geles de agarosa y se visualizó bajo luz UV. En tres de las cuatro biopsias se observó una banda de 120 pares de bases, aproximadamente, correspondiente al tamaño esperado de la fracción del minicírculo. La técnica de PCR fue el único método que detectó la presencia del parásito. Estos resultados demostraron que la sensibilidad de la PCR acelera los procesos de incriminación vectorial de las especies vectoras de leishmaniasis.

El grupo verrucarum comprende insectos vectores de Leishmania spp. y Bartonella bacilliformis, y se le considera uno de los grupos de flebotomíneos neotropicales más importantes en salud pública. Debido a la marcada semejanza morfológica entre las especies agrupadas, la identificación de algunos vectores se dificulta al utilizar caracteres taxonómicos convencionales, lo que ha hecho que sean objeto de estudio a través de quetotaxia, morfometría, sistema espiracular larval, estructura coriónica, morfología del atrio genital, citogenética, filogenética morfológica, isoenzimas, amplificación al azar de ADN polimórfico, hidrocarburos cuticulares, hibridación de ADN y secuencias nucleotídicas nucleares y mitocondriales. En la actualidad, el grupo se encuentra dividido en cuatro series de especies, verrucarum, serrana, townsendi y pia, con base en características de la terminalia masculina. Después de la revisión efectuada por Young y Duncan en 1994, se han descrito diez nuevos taxones, en su mayoría de origen andino, pertenecientes a las series verrucarum (Lutzomyia maranonensis, Lutzomyia cajamarcensis, Lutzomyia antioquiensis, Lutzomyia falcaorum), serrana (Lutzomyia robusta, Lutzomyia guilvardae) y pia (Lutzomyia suapiensis, Lutzomyia tihuiliensis, Lutzomyia tocaniensis, Lutzomyia limafalcaoae), lo que eleva a 40 el número de especies agrupadas. Esta diversidad parece ser el resultado de distintos eventos climáticos y biogeográficos entre los que se destacan el aislamiento de poblaciones ancestrales durante el cuaternario, el elevamiento de los Andes como barrera geográfica y el surgimiento del istmo de Panamá, lo que facilitó la dispersión de especies entre Sur y Centroamérica. El presente artículo revisa los más recientes avances en el conocimiento de la sistemática, biogeografía y evolución del grupo verrucarum, con énfasis en los 19 taxones presentes en Colombia.

We studied the distribution of sandflies (Diptera: Phlebotominae) - insect vectors of several diseases, including leishmaniasis - at the interface between primary forest and cattle pasture and between primary forest and secondary forest (< 15 yr old) in Southern Brazilian Amazonia. Sandflies were collected by using a combination of light traps and traps having vertebrates as baits. Strong differences in abundance and species richness were found between primary forests and pastures. Very few sandfly species were found in the pastures, and those that were found generally occurred at lower densities when compared to the adjacent forest. At least one species (Lutzomyia lainsoni), however, can become extremely abundant in pastures, possibly depending on the presence of cattle and water bodies. Differences between primary forests and secondary forests were not so strong, although the latter usually had fewer species and lower population abundances. No species were exclusively found in pastures or secondary forests; the species present in these two habitats were a subset of those found in primary forests. The distance to the edge did not affect the abundance, richness and composition of sandfly species in primary forests. The abundance and richness of sandflies, however, was greater in forest edges facing pastures than those facing secondary forests. This pattern could not be explained by an influx of species and individuals from the adjacent pasture, suggesting the existence of in situ differences between the different types of forest edges studied.

From September 1993 to August 2001, 7,190 phlebotomine were collected with CDC light trap in an endemic area for human leishmaniasis, in the departments of Misiones and Itapúa, Paraguay. Eleven species were identified: Lutzomyia neivai (93.7%), L. whitmani (4.1%), and L. fischeri, L. shannoni, L. migonei, L. misionensis, L. cortelezzii, L. pessoai, L. alphabetica, Brumptomyia avellari and B. guimaraesi (less than 1%). The last three species are new records for the country. The biodiversity and phlebotomine abundance were associated with the proximity to primary forest or gallery forest, but L. neivai was also found in peridomestic periurban environment. L. neivai was found throughout the year, and showed a period of higher activity from September to April (spring to fall) with a unimodal or bimodal pattern in relation to the annual rainy peaks during the summer. Background literature about phlebotomine from Paraguay has been reviewed.

Con el propósito de establecer algunas características citogenéticas de cinco especies nativas de Lutzomyia, correspondientes a la serie townsendi del grupo verrucarum: Lutzomyia longiflocosa, Lutzomyia quasitownsendi, Lutzomyia spinicrassa, Lutzomyia torvida y Lutzomyia youngi, se llevó a cabo un estudio comparativo entre los cariotipos y su morfometría cromosómica. A partir de ganglios cerebrales de larvas de IV estadio, se prepararon los cromosomas mitóticos mediante la técnica de aplastamiento (squash) del tejido. Se efectuaron las mediciones cromosómicas, atendiendo los siguientes parámetros: brazo corto, brazo largo, relación de brazos, longitud total, longitud relativa, índice centromérico y longitud relativa promedio. Se clasificaron los cromosomas según su morfometría y posición del centrómero siguiendo patrones estandarizados. Se calculó la distancia taxonómica y con base en estos datos se separaron las especies y se ubicaron en un fenograma. Las cinco especies de flebótomos presentaron 4 pares de cromosomas, número diploide (2N=8), y el número fundamental fue de 16. En ninguno de los cariotipos se observó heteromorfismo sexual cromosómico. El análisis estadístico de los datos de morfometría cromosómica mostró diferencias altamente significativas entre los pares cromosómicos de las cinco especies. Sin embargo, la longitud total del genoma en los flebotómos fue muy similar, a excepción de L. youngi. En conclusión, las especies íntimamente relacionadas se lograron diferenciar a nivel citotaxonómico.

El objetivo de este estudio fue estandarizar el método OMS para determinar susceptibilidad a insecticidas en algunas especies de Lutzomyia en condiciones de laboratorio y de campo. Los ensayos biológicos se realizaron sin insecticida, únicamente con tratamientos controles para determinar mortalidad por manipulación y otras condiciones desfavorables para cada especie. Se emplearon hembras de tres colonias de laboratorio: dos cepas de Lutzomyia longipalpis y una de Lutzomyia serrana. También se incluyeron en el estudio hembras silvestres de Lutzomyia quasitownsendi. Se emplearon dos tipos de métodos: el método OMS y el método OMSadaptado; este último consistió en reemplazar el tubo OMS para el periodo posexposición por un contenedor plástico con yeso humedecido. Para cada método se ensayaron tres tipos de papeles: papel impregnado con aceite de oliva, papel impregnado con aceite de silicona y papel sin aditivos. La variable por medir fue el porcentaje de mortalidad a las 24 h. El método OMS resultó conveniente para las dos cepas de L. longipalpis con una mortalidad entre 0 y 10%, pero registró una mortalidad elevada en L. serrana (20-80%) y L. quasitownsendi silvestres (10-50%). Con el método OMS-modificado, la mortalidad promedio fue inferior a 4% en todas las especies ensayadas. Con respecto al tipo de papel, no se encontraron variaciones importantes. Según los resultados, el recipiente utilizado en el periodo posexposición afecta la supervivencia de los flebótomos y de manera variable para cada especie. Al establecer líneas base de susceptibilidad a insecticidas en especies del género Lutzomyia, se recomienda el uso del método OMS para L. longipalpis y del método OMS-modificado para L. serrana, L. quasitownsendi y especies cercanas.