A description is presented of Lutzomyia tolimensis sp. nov., a new species of the subgenus Helcocyrtomyia, series sanguinaria. It was collected in dwellings, peridomestic environment and in nearby forest patches located in the foothills of the Andean Central Cordillera, where in 2004-2006 occurred the largest epidemic ever recorded of leishmaniasis in Colombia. The male of this species is differentiated from other members of the series sanguinaria based on the following combination of characters: (i) base of coxite with 0-3 subequal setae, (ii) spines of gonostyle organized in positions 2.1.2, (iii) spines inserted on distal half of gonostyle and (iv) relationship of alar indices. The female is recognized principally by the following characters: (i) palpomere V longer than III, (ii) length of labro-epipharynx and (iii) relationship of the alar indices.

Durante más de tres décadas el uso de insecticidas químicos ha sido la principal medida de control para la fiebre de dengue en el departamento del Atlántico, Colombia. Se evaluó el estado de la susceptibilidad a insecticidas de uso en salud pública de tipo organoclorado, organofosforado, piretroide y carbamato en poblaciones de A. aegypti del departamento del Atlántico. Se realizaron ensayos biológicos aplicando la metodología estandarizada por el Centro de Control y Prevención de Enfermedades (CDC), con dosis diagnóstica para deltametrina (6,25 µg/ml), lambdacialotrina (6,25 µg/ml), malatión (100 µg/ml), fenitrotión (75 µg/ml), propoxur (12,5 µg/ml) y dicloro-difenil-tricloretano DDT (150 µg/ml) en mosquitos de A. aegypti (F2) de los municipios de Barranquilla, Soledad (Villa Katanga y Floresta), Malambo, Puerto Colombia y Baranoa. Todas las poblaciones mostraron susceptibilidad al malatión y deltametrina, cinco a fenitrotión, cuatro a propoxur y dos a lambdacialotrina. En todas se evidenció pérdida de susceptibilidad al diclorodifenil- tricloretano. No se encontraron diferencias significativas en los porcentajes de mortalidad entre las poblaciones para malatión (p = 0,15), DDT (p = 0,54) y deltametrina (p = 0,99); mientras que para lambdacialotrina (p << 0,01), propoxur (p < 0,01) y fenitotrión (p << 0,01) se encontraron diferencias significativas. La aplicación de insecticidas químicos para el control de la fiebre de dengue en el departamento del Atlántico ha generado pérdida de la susceptibilidad en las poblaciones del mosquito vector.

For more than three decades, chemical insecticides have been the principal measure to control dengue fever in the department of Atlán tico, Colombia. We evaluated the status of susceptibility to insecticides that are used in public health like organophosphates, organochlorates, pyrethroids and carbamates on populations of A. aegypti in the department of Atlántico. Biological assays were performed applying the standardized methodology of the Center for Disease Control and Prevention (CDC), with diagnostic doses of deltamethrin (6.25 µg/ml), lambda-cyhalothrin (6.25 µg/ml), malathion (100 µg/ml), fenitothrion (75 µg/ml), propoxur (12.5 µg/ml) and dichlorodiphenyltrichloroethane DDT (150 µg/ml) on A. aegypti mosquitoes (F2) from the municipalities of Barranquilla, Soledad (Villa Katanga and Floresta), Malambo, Puerto Colombia and Baranoa. All the evaluated populations showed susceptibility to malathion and deltamethrin, five to fenitothrion, four to propoxur and two to lambda-cyhalothrin. All of them expressed loss of susceptibility to DDT. No significant differences were found in percent mortality between populations for malathion (P = 0.15), dichlorodiphenyltrichloroethane (P = 0.54) and deltamethrin (P = 0.99), while significant differences were found for lambda-cyhalothrin (P << 0.01), propoxur (P < 0.01) and fenitothrion (P << 0.01). The application of chemical insecticides for the control of dengue fever in the department of Atlántico has generated the loss of susceptibility in populations of the mosquito vector.

A new species of Culicoides of the subgenus Diphaomyia Vargas from high altitudes of the Andes in Colombia is described and photographied. The species is compared with its similar congener Culicoides marinkellei Wirth & Lee. Data on the collecting site and notes on the species daily activity are also provided.

The breeding sites of Culicoides pachymerus are described for the first time in western Boyacá Province, Colombia, where this species is a public health problem. In addition to being a nuisance due to its enormous density and its high biting rates, C. pachymerus cause dermatological problems in the human population. Analysis of microhabitats by the sugar flotation technique and the use of emergence traps allowed us to recover 155 larvae of Culicoides spp and 65 adults of C. pachymerus from peridomiciliary muddy substrates formed by springs of water and constant rainwater accumulation. These important findings could aid in the design of integrated control meas-ures against this pest.

La fiebre de dengue es endémica para el departamento del Atlántico; en 2007 se presentaron 3,104 casos. Para la prevención y control de esta enfermedad se ha usado el larvicida temefos. Sin embargo, se desconoce si la presión a la que han sido sometidas las poblaciones de Aedes aegypti con este insecticida ha generado resistencia. Se evaluó la susceptibilidad a temefos en larvas de A. aegypti en siete municipios y un corregimiento del departamento del Atlántico, entre el 2007 y el 2008. Se realizaron bioensayos utilizando la concentración diagnóstica para temefos (0,012 ppm) en larvas de tercer y cuarto estadio temprano de A. aegypti (F2) aplicando la metodología recomendada por la Organización Mundial de la Salud (OMS). Se realizaron dos repeticiones, cada una con cuatro réplicas y un control. En dos localidades se registró susceptibilidad al temefos (mortalidad de 100%), en cuatro se requiere verificación para vigilancia (mortalidades entre 86% - 93%) y en dos se presentó resistencia (mortalidad de 34% y 45%). Se encontraron diferencias significativas en los porcentajes de mortalidad entre las poblaciones (Kruskal-Wallis, P < 0.05). Es necesario monitorear las poblaciones de este vector en el departamento del Atlántico con el fin de generar la línea base de susceptibilidad que permita implementar estrategias preventivas y métodos alternativos de control pertinentes a cada localidad para disminuir la presión de selección a la que están sometidas las larvas por la aplicación de este larvicida

Dengue fever is endemic to the department of Atlántico; in 2007, there were 3,104 cases reported. The larvicide temephos has been used for the prevention and control of the disease. However, it is unknown if the selective pressure exerted on Aedes aegypti populations by this insecticide has generated resistance. The susceptibility of A. aegypti larvae to temephos was evaluated in seven municipalities and one county of the department of Atlántico between 2007 and 2008. Bioassays were performed using diagnostic doses of temephos (0.012 ppm) on third and early fourth Instar larvae of A. aegypti (F2), following a methodology recommended by the World Health Organization. Two repetitions were conducted, each one with four replicates and control. Susceptibility to temephos was registered for two sites (mortality rate 100%), four sites require verification for surveillance (mortality rates between 86 - 93%), and two showed resistance (mortality rates 34 - 45%). Significant differences were found in the mortality rates among populations (Kruskal-Wallis, P < 0.05). It is necessary to monitor the populations of this vector in the department of Atlántico to generate the baseline for susceptibility that will allow the implementation of preventive strategies and alternative control methods pertinent to each site, in order to reduce the selective pressure on larvae posed by the use of this larvicide