HOUSING CONDITIONS AND OBSERVATION OF TRIATOMINES AS ESTIMATION OF DOMICILIATION RISK, SANTA ROSALÍA­VICHADA (COLOMBIA) / CONDICIONES HABITACIONALES Y OBSERVACIÓN DE TRIATOMINOS COMO ESTIMACIÓN DE RIESGO DE DOMICILIACIÓN, SANTA ROSALÍA­VICHADA (COLOMBIA)

Objective: correlate between observation of triatomine in intradomicile and housing conditions and ecological environment, as risk estimate of household infestation. Materials and Methods: a descriptive cross-sectional study using structured non-random surveys, implemented in 162 homes. The analysis methods included univariate, bivariate, and models of binary logistic regression. Results: the main factors associated with triatomine observation relate to structural materials of housing, access to public services, the presence of palms, and burrowing mammals. Conclusions: the floors of dust and palm roof homes are important in household vectors, while palms and the presence of burrowing mammals suggest triatomine preference towards natural ecotopes in anthropic environments.

Objetivo: correlacionar la observación de triatominos en el intradomicilio y las condiciones habitacionales y ecológicas del entorno, como estimación de riesgo de domiciliación. Materiales y métodos: estudio transversal descriptivo, por medio de encuestas estructuradas no aleatorias, implementadas en 162 viviendas. El análisis incluyó métodos univariados, bivariados y modelos de regresión de logística binaria. Resultados: los principales factores asociados a la observación de triatominos se relacionan con los materiales estructurales de la vivienda, acceso a servicios públicos, presencia de palmas y mamíferos excavadores. Conclusiones: el piso de tierra y el techo de palma en las viviendas son importantes en la domiciliación del vector, mientras que la presencia de palmas y mamíferos excavadores sugieren la preferencia de los triatominos hacia los ecotopos naturales sobre los ambientes antrópicos.

Molecular diagnosis and genotype analysis of Giardia duodenalis in asymptomatic children from a rural area in central Colombia.

Giardiasis is a parasitic infection that affects around 200 million people worldwide. This parasite presents a remarkable genetic variability observed in 8 genetic clusters named as 'assemblages' (A-H). These assemblages are host restricted and could be zoonotic where A and B infect humans and animals around the globe. The knowledge of the molecular epidemiology of human giardiasis in South-America is scarce and also the usefulness of PCR to detect this pathogen in fecal samples remains controversial. The aim of this study was to conduct a cross-sectional study to compare the molecular targets employed for the molecular diagnosis of Giardia DNA and to discriminate the parasite assemblages circulating in the studied population. We analyzed 181 fecal samples from Children at La Virgen, Cundinamarca, Colombia that were DNA-extracted and analyzed by SSU rDNA, tpi and gdh loci. We observed positivity by microscopy of 13% and by PCR around 76-80% depending on the molecular marker. Additionally, a lack of statistical concordance between microscopy and PCR was detected. Regarding the genetic assemblages, we detected assemblage A (3%), assemblage B (90%) and mixed infections assemblages A+B (7%). Hence, the sub-assemblages were typed as AI, AII, BIII and BIV across the population. This study represents a reliable attempt to understand the molecular epidemiology of giardiasis in Colombia and the use of PCR to detect cryptic infections. The epidemiological implications are herein discussed.

Comparison of hemocytes of V-instar nymphs of Rhodniusprolixus (Stål) and Rhodnius robustus (Larousse 1927), before and after molting / Comparación de los hemocitos de las ninfas de V instar de Rhodnius prolixus (Stål) and Rhodnius robustus, antes y después de la muda (Larousse 1927)

Background. The immune response of insects involves humoral factors and cellular elements known as hemocytes. There are different reports that explore the response of hemocytes to infections, but the effect that molting has on this response has not been explored so far. We hypothesized that there would be a change in the percentage of hemocytes as a response to the molting process. Objective. The aim of this work was to compare the hemogram (CBC), the formula, and the differential count of hemocytes in IV instar before molting and in V instar nymphs 24 hours after molting in two species: Rhodnius prolixus and Rhodnius robustus. Materials and methods. We assayed different staining methodologies including Giemsa, Alcian Blue pH 2.0, Alcian Blue pH 2.6, Gomori substrate, PAS (Schiff), Sudan Black and Papanicolau with positive controls for each one. In the Gomori staining, we observed lysosomes in the granulocytes and plasmatocytes, but the differentiation was better detected using Giemsa staining. Results. There were no statistically significant differences between the two species studied in plasmatocytes (p=0,053) or even in granulocytes (p=0,5). However, differences were significant in the prohemocytes (p=0,001) during the molting process in both Rhodnius prolixus and Rhodnius robustus. Conclusions. Significant differences in prohemocytes between nymphs of IV and V instar were detected. No significant differences in the amount of cells were observed between the two species and the two stages. These findings may be explained due to their role as precursor cell of prohemocytes.

Antecedentes. La respuesta inmune de los insectos involucra factores humorales y elementos celulares llamados hemocitos. Existen varios trabajos explorando la respuesta de los hemocitos frente a infecciones, pero no como respuesta al proceso de muda. Objetivo. Comparar el hemograma: la fórmula y el recuento diferencial de hemocitos de Rhodnius prolixus y Rhodnius robustus en ninfas de IV estadio antes de la muda y ninfas de V estadio 24 horas después de la muda. Materiales y métodos. Se ensayaron las coloraciones Giemsa, Alcian Blue pH 2.0, Alcian Blue pH 2.6, sustrato Gomori, PAS (Schiff), Sudán Negro, Papanicolau, con controles positivos para cada una. Con la coloración de Gomori se observaron lisosomas en los granulocitos y en plasmatocitos, pero la diferenciación se logró mejor con la coloración de Giemsa. Resultados. Los plasmatocitos fueron más abundantes en las ninfas de IV estadio de Rhodnius robustus y en las de V estadio de las dos especies, pero en las ninfas de V estadio de R. prolixus, el recuento de prohemocitos fue mayor; para los oenocitoides, esferulocitos y adipohemocitos el recuento no alcanzó al 1 %. En las dos especies no se encontraron diferencias estadísticamente significativas en plasmatocitos (p=0,05319), ni en granulocitos (p=0,5), entre las ninfas de IV y V estadio, pero fue significativa en prohemocitos (p=0,001). Conclusiones. Se detectaron diferencias significativas en prohemocitos entre las ninfas de IV y V estadio. No hubo un aumento significativo en el conteo de células en los diferentes estadios.

Comportamiento de Rhodnius robustusLarousse,1927 (Hemiptera, Reduviidae) durante su alimentaciónen condiciones de laboratorio / Feeding behavior of Rhodnius robustus Larouse, 1927 (Hemiptera, Reduviidae) under laboratory conditions

Introducción.A pesar del control de los insectos domiciliados, se siguen presentando casos de enfermedad de Chagas con la participación en la transmisión de especies peridomiciliarias y selváticas, una de las cuales es Rhodnius robustus, especie reportada con infecciones naturales de Trypanosoma cruzi y T. rangeli. Objetivo. Describir el comportamiento de R. robustus durante su alimentación en condiciones de laboratorio. Materiales y métodos. En cada estadio de desarrollo de R. robustus se analizó el tiempo promedio para alcanzar la repleción, número promedio de deyecciones, porcentaje de individuos que defecan durante la comida y ganancia de peso después de la alimentación. Resultados. Rhodnius robustus tardó entre 19:26 y 44:55 (minutos:segundos) en alimentarse a repleción; los insectos defecaron en todos sus diferentes estadios durante la alimentación. El porcentaje de individuos que defecan durante la alimentación varía de 13,3 % a 93,3 %. Por otro lado, el consumo promedio de sangre en el quinto estadio, 337,19 mg, duplica la cantidad ingerida por los adultos, 161,25 mg. Conclusiones. En todos los estadios de R. robustus hay defecación durante la alimentación, factor que favorece su competencia vectorial. Sin embargo, el tiempo para la primera deyección, el porcentaje de deyecciones y los individuos que defecan durante la comida, así como la cantidad de sangre ingerida, varían entre los estadios, lo cual indica que el comportamiento alimenticio está mediado por variables dependientes de la edad/estadio.

Introduction: Despite of indoor insect control measures, American trypanosomiasis cases still occur, with the participation of both peridomestic and sylvan species. One of these species is Rhodnius robustus, which has been found naturally infected with Trypanosoma cruzi and Trypanosoma rangeli. Objective: To describe the feeding behavior of R. robustus under laboratory conditions. Materials and methods: We analyzed time spent for repletion, the number of defecations, the percentage and number of times insects defecated during blood intake, and the weight gained after blood feeding in each nymph stage of R. robustus. Results: Repletion for R. robustus took between 19:26 to 44:55 (minutes:seconds) and all nymph stages defecated during blood feeding. The proportion of individuals which defecated during blood feeding varied between 13.3% and 93.3%. On the other hand, the highest average blood intake was observed in the fifth stage (337.19 mg), which is twice the blood intake of adults (161.25 mg). Conclusions: All stages of R. robustus dejected during blood feeding, which is an important factor for its vectorial competence. Nevertheless, the time prior to the first dejection, the percentage of dejections and number of individuals that dejected upon blood feeding, as well as the amount of ingested blood varied among stages, which means that feeding behavior is mediated by variables depending on age/stage.

[Evaluation (assessment) of three tests for diagnosis of geohelmints in Colombia]. / Evaluación de tres pruebas para el diagnóstico de geohelmintos en Colombia.

INTRODUCTION: Soil-transmitted helminth infections are considered a public health problem in developing countries. The diagnostic tests, both for individual parient diagnosis as for population studies should be evaluated in terms of validity and reliability. OBJECTIVE: To compare the direct examination, the modified Ritchie-Frick method, a Kato-Katz designed by a Brazilian group and one designed by the WHO, for the diagnosis of soil-transmitted helminthes. MATERIALS AND METHODS: A diagnostic test reliability study was performed. The same stool sample was analyzed by the same observer using four diagnostic tests. 204 samples were obtained, 194 of those fulfilled the inclusion criteria and were analyzed. The observers did not know the participants' identity neither the other tests results. For the analysis the Kato-Katz (WHO) was considered as the gold standard. For the reliability assessment percent agreement, positive percent agreement, Kappa statistic, and intraclass correlation were performed. RESULTS: The Brazilian Kato-Katz showed a good performance with high sensitivity and specificity for T. trichiura and Hookworm with values of 0.97 and 0.96 respectively, and a high specificity with mild sensitivity for A. lumbricoides (0.95 and 0.79) meanwhile the direct examination and the Ritche-Frick method showed a performance between mild and poor. The differences were higher for hookworm and Trichiuris trichiura than for Ascaris lumbricoides. CONCLUSION: The Brazilian Kato Katz test could be implemented, but further studies are needed to correlate its operative capacity with its feasibility, availability and cost.

[Feeding behavior of Rhodnius robustus Larouse, 1927 (Hemiptera, Reduviidae) under laboratory conditions]. / Comportamiento de Rhodnius robustus Larousse,1927 (Hemiptera, Reduviidae) durante su alimentaciónen condiciones de laboratorio.

INTRODUCTION: Despite of indoor insect control measures, American trypanosomiasis cases still occur, with the participation of both peridomestic and sylvan species. One of these species is Rhodnius robustus, which has been found naturally infected with Trypanosoma cruzi and Trypanosoma rangeli. OBJECTIVE: To describe the feeding behavior of R. robustus under laboratory conditions. MATERIALS AND METHODS: We analyzed time spent for repletion, the number of defecations, the percentage and number of times insects defecated during blood intake, and the weight gained after blood feeding in each nymph stage of R. robustus. RESULTS: Repletion for R. robustus took between 19:26 to 44:55 (minutes:seconds) and all nymph stages defecated during blood feeding. The proportion of individuals which defecated during blood feeding varied between 13.3% and 93.3%. On the other hand, the highest average blood intake was observed in the fifth stage (337.19 mg), which is twice the blood intake of adults (161.25 mg). CONCLUSIONS: All stages of R. robustus dejected during blood feeding, which is an important factor for its vectorial competence. Nevertheless, the time prior to the first dejection, the percentage of dejections and number of individuals that dejected upon blood feeding, as well as the amount of ingested blood varied among stages, which means that feeding behavior is mediated by variables depending on age/stage.

Caracterización preliminar de los sitios de cría de Aedes (Stegomyia) albopictus (Skuse, 1894) (Diptera: Culicidae) en el municipio de Leticia, Amazonas, Colombia / Characterization of Aedes albopictus (Skuse, 1894) (Diptera: Culicidae) larval habitats near the Amazon River in Colombia

Introducción. Dada la importancia de Aedes albopictus en la salud pública, es necesario caracterizar los criaderos para establecer medidas de control. Objetivo. Caracterizar en función de los parámetros físico-químicos y grupos de organismos presentes, los criaderos de los estadios inmaduros de Ae. albopictus en Leticia, Amazonas. Materiales y métodos. Se inspeccionaron 154 viviendas en el área urbana en diciembre 2002 y enero 2003, para buscar criaderos de Ae. albopictus y otros dípteros con estadios acuáticos inmaduros. En los criaderos con resultados positivos se tomaron datos físico-químicos cualitativos y cuantitativos: exposición al sol, ubicación, tamaño, material, conductividad, turbidez, oxígeno disuelto, temperatura y presencia de macroinvertebrados y plancton. Los resultados se compararon mediante análisis descriptivos, análisis de componentes principales, dendrogramas de clasificación e índices de diversidad. Resultados. Se encontraron 21 criaderos con larvas de dípteros, 13 con Ae. albopictus; 92% de ellos estaban ubicados en el peridomicilio, en recipientes pequeños o medianos, dispuestos en la sombra, con baja turbidez y conductividad, bajos índices de diversidad para macroinvertebrados y altos para organismos productores de plancton. En el análisis de componentes principales, se encontró correlación significativa con ácaros, oligoquetos y hemípteros (macroinvertebrados), y con bacilarofíceas, clorofíceas y cianofíceas (plancton). En presencia de otros culícidos, las larvas de Ae. albopictus fueron escasas. Conclusión. En este estudio se encontró que las hembras de Ae. albopictus depositan sus huevos en depósitos de agua recién establecidos con disponibilidad suficiente de recurso, baja conductividad y turbidez, y menor competencia intraespecífica e interespecífica.

Introduction. Because the role of Aedes albopictus as an incriminated vector of several viral pathogens, its control is important to human health. To establish appropriate control methods, characterization of the larval habitats is a necessary first step. Objective. Habitats of the immature stages of Ae. albopictus were characterized with respect to physical-chemical parameters and by floral and faunal arrays present. Materials and methods. Leticia is located at the southern most tip of Colombia on the banks of the Amazon River. In the urban area, 154 houses were inspected in December 2002 and January 2003. Physical-chemical data were collected, including exposure to sunlight, location, container size and material, water conductivity, and dissolved oxygen. Macroinvertebrates and plankton samples were taken at each positive larval site. The results were compared using descriptive analysis, principal component analysis, classification dendrograms, and diversity indexes. Results. Twenty-one habitats were found positive for Diptera, and 13 were positive for Ae. albopictus larvae. Most of the positive habitats (92%) were located near the houses-they were small or medium size receptacles located in the shade. This water generally had low conductivity and low turbidity, although high values of these parameters were also identified. The habitats had low diversity indexes for macroinvertebrates and high diversity indexes for plankton. In the principal component analysis, significant correlation was found with mites, oligochaetes and hemipterans (the macroinvertebrates) and with bacilarophyceaes, clorophyceaes and cianophyceas (the algal forms). Conclusion. In Leticia, females of Ae. albopictus were found in newly established habitats with sufficient availability of resources, low conductivity, and turbidity, lower intra-and interspecific competition.

[Characterization of Aedes albopictus (Skuse, 1894) (Diptera:Culicidae) larval habitats near the Amazon River in Colombia]. / Caracterización preliminar de los sitios de cría de Aedes (Stegomyia) albopictus (Skuse, 1894) (Diptera: Culicidae) en el municipio de Leticia, Amazonas, Colombia.

INTRODUCTION: Because the role of Aedes albopictus as an incriminated vector of several viral pathogens, its control is important to human health. To establish appropriate control methods, characterization of the larval habitats is a necessary first step. OBJECTIVE: Habitats of the immature stages of Ae. albopictus were characterized with respect to physical-chemical parameters and by floral and faunal arrays present. MATERIALS AND METHODS: Leticia is located at the southernmost tip of Colombia on the banks of the Amazon River. In the urban area, 154 houses were inspected in December 2002 and January 2003. Physical-chemical data were collected, including exposure to sunlight, location, container size and material, water conductivity, and dissolved oxygen. Macroinvertebrates and plankton samples were taken at each positive larval site. The results were compared using descriptive analysis, principal component analysis, classification dendrograms, and diversity indexes. RESULTS: Twenty-one habitats were found positive for Diptera, and 13 were positive for Ae. albopictus larvae. Most of the positive habitats (92%) were located near the houses--they were small or medium size receptacles located in the shade. This water generally had low conductivity and low turbidity, although high values of these parameters were also identified. The habitats had low diversity indexes for macroinvertebrates and high diversity indexes for plankton. In the principal component analysis, significant correlation was found with mites, oligochaetes and hemipterans (the macroinvertebrates) and with bacilarophyceaes, clorophyceaes and cianophyceas (the algal forms). CONCLUSION: In Leticia, females of Ae. albopictus were found in newly established habitats with sufficient availability of resources, low conductivity, and turbidity, lower intra-and interspecific competition.

[Pediculosis prevalence and associated risk factors in a nursery school, Bogotá, Colombia]. / Prevalencia y factores asociados a la pediculosis niños de un jardín infantil de Bogotá

INTRODUCTION: Pediculosis is one of the most important chronic infestations in schoolchildren worldwide. Infestations show a high prevalence among the poorest children in developing countries, and it is associated with substandard hygienic practices. OBJECTIVE: The prevalence was estimated and seasonality described of a Pediculus infestation of seven months duration in a nursery school. Associations were explored among the standards of hygienic practices and hair characteristics. MATERIALS AND METHODS: One hundred and seventy-eight nursery school children between the ages of 3 months to 5 years, from the nursery school located at National University of Colombia, Bogotá, were participants in the study. The children were examined for presence of Pediculus humanus infestation each month for seven months. The lengths and thicknesses of hair were measured at the first examination. A survey requesting information on socioeconomic and hygienic practices was provided to the caretakers of the children. Prevalence rates with 95% confidence intervals were estimated for each explored association, and also to describe the differences of prevalences between age groups in each period. RESULTS: The highest prevalence was found in the children between the ages of 4 and 5 years, at the beginning of the school year. A positive association was indicated between Pediculus infestation and hair longer than 11.5 cm [prevalence rate (PR)=2.0; 95% confidence interval (CI): 0.82-4.8], washing the hair less than three times a week (PR=1.58; 95%CI: 0.58-4.7), as well as sharing cleaning implements (PR=1.31; 95%CI: 38-4.46) and living with more than five people at home (PR=2.04; 95%CI: 0.8-5.06). Due to the limited size of the sample, none of the associations found were statistically significant. CONCLUSION: Pediculus infestation has a high prevalence in children of the nursery school studied. This infestation is associated with substandard hygienic practices, living with more than five people at home and the length of hair.

Prevalencia y factores asociados a la pediculosis en niños del Jardín Infantil de la Universidad Nacional de Colombia / Pediculosis prevalence and associated risk factors in children of the nursery school, Bogotá, Colombia

Introducción. La pediculosis es una de las infestaciones crónicas más importante en escolares en el mundo.Objetivo. Estimar la prevalencia y describir la estacionalidad de la pediculosis durante siete meses en un jardín infantil y explorar su asociación con las variables socioeconómicas, las prácticas de higiene y las características del cabello. Materiales y métodos. Ciento setenta y ocho niños entre 3 y 60 meses de edaddel jardín infantil de la Universidad Nacional de Colombia participaron en el estudio. En cada niño se exploró la presencia de Pediculus humanus mensualmente por siete meses y se midió el grosor y la longitud del cabello al comienzo del seguimiento. Se realizó una encuesta a los cuidadores de los sujetos de estudio sobre prácticas higiénicas y condiciones socioeconómicas.Resultados. Se encontraron mayores prevalencias en el grupo de edad entre 48 a 59 meses, al principio del año escolar. Estos resultados sugieren una asociaciónpositiva entre la pediculosis y tener una longitud del cabello mayor de 11,5 centímetros [Razón de prevalencia (RP): 2,0; intervalo de confianza (IC) del 95 por ciento:0,82-4,8 ], el bañarse la cabeza menos de tres veces a la semana (RP: 1,58; IC 95 por ciento: 0,58-4,7), el compartir implementos de aseo (RP:1,31; IC 95 por ciento: 0,38-4,46) y el vivir más de cinco personas en la casa (RP; 2,04: IC 95 por ciento: 0,8-5,06). Conclusión. La infestación por P. humanus capitis tiene altas prevalencias en los escolares del jardín. Esta infestación se encuentra asociada a las malas prácticas higiénicas, al hacinamiento y la longitud del cabello.

[Seroprevalence of canine visceral leishmaniasis in sector 8 of Neiva and in four municipalities of Huila, Colombia]. / Seroprevalencia de leishmaniosis visceral canina en la comuna 8 de Neiva y en cuatro municipios de Huila, Colombia.

INTRODUCTION: Canine visceral leishmaniasis in endemic areas of Colombia could be a public health risk factor given the zoonotic nature of the disease. Ninety-six human cases of visceral leishmaniasis were reported in Colombia in 2004, 5 of them in Huila, where Lutzomyia longipalpis has been incriminated as the main vector species. OBJECTIVE: To determine the prevalence of IgG antibodies against Leishmania chagasi in dogs from the sector 8 of the city of Neiva and the from the towns of Villavieja, Algeciras, Palermo and Rivera located in Huila, Colombia. MATERIALS AND METHODS: An epidemiological survey was carried out in 610 dogs, which included clinical examination and venopuncture for obtaining blood samples. Authorization was obtained from the dog owners. The sera were analyzed by the ELISA test with promastigotes of the L. chagasi strain MHOM/CO84/CLO44B as antigen. RESULTS: The canine population had an average age of 2.5 years; 67.3% of the dogs were males and the cross-bred animals were the most prevalent constituting 85% of those samples. On clinical examination the main signs were onicogriphosis 24.3%, lymphadenitis 10% and skin lesions 5%. The presence of antibodies was observed in 28.1% of the dogs from sector 8 of Neiva, 28% in Villavieja, 14.9% in Rivera, 10% in Palermo and 5.1% in Algeciras. An average ratio of five people cohabitating per seropositive dog was observed. CONCLUSIONS: The results reflect the exposure to Leishmania chagasi infection of dogs living in both urban and rural environments in the studied zones, and should encourage health authorities to carry out control measures to prevent the spread of this zoonotic disease.

Ciclo de vida de Culex quinquefasciatus Say, 1826 (Diptera Culicidae) bajo condiciones no controladas en Bogotá / Life cycle of Culex quinquefasciatus Say (Diptera: Culicidae) under uncontrolled conditions

El objetivo de este trabajo fue estudiar varios aspectos del crecimiento y el desarrollo de los estadios inmaduros de Culex quinquefasciatus Say, 1826 (Diptera: Culicidae), especie antropofílica frecuentemente encontrada en Bogotá. Con este fin, se realizaron dos experimentos en diferentes épocas del año 2001 (enero-febrero y septiembre-octubre), bajo condiciones no controladas (luz, temperatura y humedad relativa). Se colocaron recipientes plásticos transparentes con agua de charca a la que se le adicionó concentrado para perro; se tomaron cuatro balsas al azar para estudiar el ciclo de vida utilizando los parámetros de la tabla de vida: mortalidad y supervivencia. Las hembras ovipositaron entre cinco y ocho días después de la ingestión de sangre. El número de huevos por balsa varió entre 152 y 203. La eclosión de larvas L1 fue de 50 por ciento en el primer experimento y de 75 por ciento en el segundo. Se destacó la naturaleza no sincrónica de la eclosión de las L1, la menor duración proporcional del estadio de pupa (11 por ciento del tiempo del desarrollo total) y la eficiencia del cambio pupa-adulto (98,61 por ciento). Se reporta una menor duración del ciclo de lo informado previamente. Además, los altos porcentajes de eclosión (83,58 por ciento), pupación (86,63 por ciento) y emergencia (98,61 por ciento) con las condiciones presentes para estos experimentos (temperatura media 14,8°C y 15,1°C y humedad relativa del 72,5 por ciento y 74,1 por ciento, respectivamente) indican el alto grado de adaptación de C. quinquefasciatus al ambiente bogotano. Estas características, más la capacidad vectorial y la resistencia a los insecticidas, hacen de esta especie un problema de salud pública

[Life cycle of Culex quinquefasciatus Say (Diptera: Culicidae) under uncontrolled conditions]. / Ciclo de vida de Culex quinquefasciatus Say, 1826 (Diptera: Culicidae) bajo condiciones no controladas en Bogotá.

Aspects of the growth and development were described for immature stages of Culex quinquefasciatus Say, 1826 (Diptera: Culicidae), an antropophilic mosquito species found frequently in Bogotá, Colombia. Two experiments were carried out during January-February and September-October of 2001 under ambient environmental conditions. Oviposition occured 5-8 days after blood ingestion. Females laid eggs in plastic containers filled with pooled water with high organic material content. The number of eggs per raft varied between 152 and 203. For the 2 trials, the hatch rate was 50% and 75%. The asynchronous egg hatch, the short duration of the pupal stage (11% of the total development time, and the high efficiency of adult emergence from the pupal stage (98.6%) were noted. In general, these development times were shorter compared to those reported by other authors. Moreover, the high percentages of hatch (83.6%), pupation (86.6%) and emergence (98.6%) under the average temperature conditions of 14.8 degrees C and 15.1 degrees C, and average relative humidity of 72.5% and 74.1%, respectively) demonstrated adaptation of C. quinquefasciatus to Bogotá's cool, high altitude environment. These characteristics, together with its vectorial capacity and the resistance to chemical control methods, could make this species become a risk for the health of human populations.

Simuliidae (Insecta: Diptera) de Colombia. IV-Clave Grafica para la Identificacion de los Simulidos de la Region de la Calera, Cundinamarca / Simuliidae (Insecta: Diptera) of Colombia: IV-Graphic Key for the Identification of Simuliidae of the Calera Region in Cundinamarca

Los simulidos pertenecen al grupo de insectos de importancia medica por estar involucrados en la transmision de varias filarias a los humanos y a otras especies utiles para el hombre como aves, bovinos, equinos y porcinos. Se ofrece una clave grafica para siete especies de la familia Simuliidae presentes en el Rio Teusaca y sus afluentes, Municipio de la Calera. La clave considera los diferentes estadios del desarrollo: larva, pupa, adulto (macho y hembra)