ABSTRACT
The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.
Subject(s)
Animals , Animal Distribution/physiology , Culex/growth & development , Ecosystem , Seasons , Magnoliopsida , Argentina , Aquatic Organisms/physiology , Larva , Meteorological Concepts , Mosquito Control/methods , Population Growth , Water/parasitologyABSTRACT
The presence of Aedes aegypti is reported beyond its current limit of distribution in Argentina, in the city of Neuquén, Neuquén Province. Ovitraps were placed to collect Ae. aegypti eggs between December 2009 and April 2010. The geographical distribution of Culex eduardoi, Psorophora ciliata and Ps. cingulata is extended with new records from two provinces.
Relata-se a presença de Aedes aegypti ao sul de seu limite atual de distribuição na Argentina, na cidade de Neuquén, província de Neuquén. Ovitrampas foram instaladas de dezembro/2009 a abril/2010. A distribuição geográfica de Culex eduardoi, Psorophora ciliata e Ps. cingulata aumenta, incluindo novos registros para duas províncias.
Se reporta la presencia de Aedes aegypti al sur de su límite actual de distribución en Argentina, en la ciudad de Neuquén, provincia de Neuquén. Huevos de esta especie fueron colectados mediante el uso de ovitrampas que fueron colocadas de diciembre/2009 a abril/2010. La distribución geográfica de Culex eduardoi, Psorophora ciliata y Ps. cingulata se amplía, incluyendo nuevos registros para dos provincias.
Subject(s)
Animals , Female , Male , Culicidae/classification , Argentina/epidemiology , Culicidae/physiology , Dengue/epidemiology , Larva/classification , Larva/physiologyABSTRACT
El objetivo del estudio fue determinar los horarios de máxima actividad de oviposición de Aedes aegypti en la ciudad de Orán (noroeste argentino). Se realizaron muestreos quincenales entre noviembre de 2006 y febrero de 2007 (primavera-verano). La ciudad fue dividida en tres zonas (norte, centro, sur), donde fueron seleccionadas al azar las viviendas para colocar dos ovitrampas en el exterior de las mismas. Las ovitrampas fueron reemplazadas cada cuatro horas, desde la mañana (8h) hasta el atardecer (20h). Se registró la mayor cantidad de huevos entre las 16 y 20 h (81 por ciento). Estos datos aportan al conocimiento del vector y, por lo tanto, de la posibilidad de control, pudiendo realizarse las fumigaciones en la franja horaria con mayor actividad de oviposición.
The study aimed to determinate the maximum daily peak of Aedes aegypti oviposition in the city of Oran, northwestern Argentina. Biweekly samplings were taken between November 2006 and February 2007 (spring-summer). The city was divided into three areas (north, center, and south) and households were randomly selected. Two ovitraps were placed outdoors in the selected houses. Ovitraps were replaced every four hours, from morning (8 a.m.) to late afternoon (8 p.m.). The largest number of eggs was recorded between 4 p.m. and 8 p.m. (81 percent). These findings enhance our understanding of the vector and thus its control such as spraying during the hours of peak oviposition activity.
O objetivo do estudo foi determinar os horários de máxima atividade de oviposição de Aedes aegypti na cidade de Orán (noroeste argentino). Foram realizadas coletas quinzenais, entre novembro de 2006 e fevereiro de 2007 (primavera-verão). A cidade foi dividida em três zonas (norte, centro, sul); foram escolhidos aleatoriamente dez domicílios em cada zona e duas ovitrampas foram instaladas no exterior de cada domicílio. As ovitrampas eram trocadas a cada quatro horas, cobrindo desde a manhã (8h) até a noite (20h). A maior quantidade de ovos (81 por cento) foi registrada entre as 16h e 20h. Esses dados aportam conhecimento do vetor e, portanto, a seu controle, como, por exemplo, realizar a fumegação na faixa horária de maior atividade de oviposição.