Micro-environmental features associated to container-dwelling mosquitoes (Diptera: Culicidae) in an urban cemetery of the Dominican Republic / Variables microambientales asociadas a mosquitos (Diptera: Culicidae) que habitan en recipientes en un cementerio urbano de República Dominicana

Abstract Mosquitoes (Diptera: Culicidae) are important vectors of diverse pathogenic organisms, particularly arboviruses and protozoa. The immature stages of mosquitoes occur in a wide range of natural or human-made aquatic habitats. On this basis, some anthropogenic places such as cemeteries, usually serve as thrive and productive artificial-breeding habitats for mosquitoes. Despite being important foci for vector species, urban cemeteries are frequently overlooked in control and surveillance programs. This study evaluates the association of ecological variables and attributes (type of material, presence of flowers, water availability and height from the ground) of the breeding sites with the levels of infestation of mosquito immature stages. In 2017, an entire urban cemetery in Jarabacoa (Dominican Republic) was sampled at two different climatic periods (March: dry and August: rainy) for the characterization of the artificial breeding-sites, collection of immature stages of culicids and subsequent laboratory rearing for species identification. In total 968 containers were studied, containing 7 758 immature stages in 203 (21.0 %) water-filled containers which accounted for four species: Culex quinquefasciatus (50.5 %), Aedes aegypti (47.1 %), Aedes albopictus (1.9 %) and Culex nigripalpus (0.4 %). The mean of A. aegypti immatures in infested containers was roughly two times higher compared to C. quinquefasciatus and significantly lower compared to A. albopictus. The total Container Index (CI) was 20.9 %, and among the type of materials, those made from rock (cement, ceramic, and mud) and plastic had the highest CI = 25.9 % and 23.4 %, respectively. Almost 95 % of the total infested water-filled containers were made of plastic or rock. No association was found between the type of material of the containers and the density of mosquitoes. However, overall, greater densities of immature stages were found at ground than at higher levels. A weak positive correlation between water volume and density was found in some species of immature stages. Significantly higher number of C. quinquefasciatus were recorded in containers with flowers and large water volume. In contrast, A. aegypti immature stages were more frequent in containers without flowers. A weak negative association between water volume and infestations was found for A. albopictus immatures. As reflected of their opportunistic behaviour and broad ecological plasticity, Culex spp. and Aedes spp. mosquitoes were abundant pests in cemetery habitats where were able to breed in almost any kind of water-filled container regardless the type of material. However, our study showed that some ecological variables have critical impact for the development of the immature stages of some species. The health authorities and cemetery keepers can benefit from these results by focusing on the implementation of detailed plans and integrated strategies for the control and prevention of cemetery infestations by mosquitoes.(AU)

Resumen Los mosquitos (Diptera: Culicidae) son importantes vectores de diversos organismos patógenos, tales como arbovirus y protozoos. Los estadios inmaduros de los mosquitos pueden encontrarse en un amplio abanico de hábitats, tanto de origen natural como humano. Algunos lugares antrópicos, como los cementerios, sirven como prósperos hábitats artificiales para el desarrollo del ciclo de vida de los mosquitos. A pesar de constituir importantes focos para especies de interés vectorial, los cementerios urbanos son frecuentemente olvidados en los programas de vigilancia y control. Este estudio evaluó la asociación de algunas variables ecológicas (tipo de material, presencia de flores, disponibilidad de agua, y altura respecto al suelo) de los lugares de cría (recipientes) con los niveles de infestación de las fases preimarginales de los culícidos. En 2017, un cementerio urbano en Jarabacoa (República Dominicana) fue inspeccionado durante dos periodos climáticos (es decir: marzo: estación seca y agosto: estación húmeda) para: caracterizar los lugares de cría artificiales, captura de los estadios inmaduros de culícidos e identificación de los adultos emergidos a partir de las fases inmaduras. En total, 968 recipientes fueron examinados, conteniendo 7 758 inmaduros en 203 (21.0 %) recipientes con agua pertenecientes a cuatro especies, Culex quinquefasciatus (50.5 %), Aedes aegypti (47.1 %), Aedes albopictus (1.9 %) y Culex nigripalpus (0.4 %). El índice de recipiente (IR) fue del 20.9 %, y los recipientes fabricados a partir de roca (cemento, cerámica y barro) y plástico tuvieron el mayor IR = 25.9 y 23.4 %, respectivamente. Casi un 95 % de los recipientes con agua infectados estaban constituidos de materiales tipo plástico o roca. No se encontró asociación entre el tipo de material del recipiente y la densidad. En general, mayor densidad de estadios inmaduros fue observada a nivel del suelo que a alturas mayores. Se observó un incremento significativo del número de C. quinquefasciatus en recipientes con flores y grandes volúmenes de agua. Por el contrario, los estadios de A. aegypti fueron más frecuentes en recipientes sin flores. Como reflejo de su comportamiento oportunista y amplia plasticidad ecológica, los mosquitos Culex y Aedes fueron abundantes en los cementerios, siendo capaces de desarrollar su ciclo de vida acuático en cualquier tipo de recipiente, con independencia del material que lo constituya. Nuestro estudio, por tanto, mostró que algunas variables ecológicas tienen un impacto crítico sobre el desarrollo de los estadios inmaduros de algunas especies de mosquitos. Tanto las autoridades de salud pública como los cuidadores del cementerio pueden beneficiare de estos resultados centrándose en la implementación de planes detallados y estrategias integradoras para el control y prevención de mosquitos que infectan cementerios.(AU)

Biting midges (Diptera: Ceratopogonidae) from an urban forest fragment in Central Amazon (Brazil): Effects of opening areas on abundance, richness, and composition

ABSTRACT We assessed the immature stages of Ceratopogonidae (Diptera) in artificial containers in an urban forest fragment in Manaus (Brazil), including their behavioral, biological and ecological information. In addition, we evaluated the effects of deforestation in an open and forested area on Ceratopogonidae communities. Immatures were sampled between August 2012 and July 2014 in artificial containers installed in both habitat types. We collected 685 immatures of seven morpho-species of Bezzia Kieffer, Culicoides Latreille, Dasyhelea Kieffer, Forcipomyia Meigen, and Palpomyia Meigen. In the open area, we recorded higher temperature and electrical conductivity values than in the forested area; however, these variables did not differ between seasons. Water volume was higher in open area and in rainy season, while pH was similar in both areas and seasons. Species richness was higher in forested area, but did not differ between seasons. We did not record differences in abundance between areas or seasons. Community composition differed between areas, but not between seasons. We provide the first records of Culicoides (Hoffmania) insignis Lutz and C. (Haematomyidium) quasiparaensis Clastrier in artificial containers from the state of Amazonas. Our results suggest that the preservation of forested areas in Amazonas is fundamental for the maintenance of the life cycle of some species of Ceratopogonidae.

Tire-breeding mosquitoes of public health importance along an urbanisation gradient in Buenos Aires, Argentina

Used vehicle tires are a source of mosquito vectors and a means of their introduction and expansion. With the aim of assessing the effects of urbanisation on the main mosquito vectors in temperate Argentina, the infestation levels of Aedes aegypti (L.) and Culex pipiens L. were studied in used tires from highly urbanised cities to low-urbanised small towns in Buenos Aires. Immatures of both species accounted for 96 percent of the 9,722 individuals collected; the total individuals collected represented seven species. The percentage of water-filled tires containing mosquitoes [container index (CI)] was 33 percent and the percentage of infested sites [site index (SI)] was 65.2 percent. These indexes decreased significantly from low to high urbanisation levels for both mosquito species. The relative abundance (RA) of Ae. aegypti immatures was slightly higher toward large cities, but showed no difference for Cx. pipiens. The CI of shaded tires was significantly higher than the CI of exposed tires for both mosquito species. There was no difference in RA values between shaded and sunlit tires. The CI and the SI were highest during the summer across the urbanisation levels, except for Cx. pipiens, which continued to increase during the autumn in small towns. Results related to urbanisation gradient, sunlit exposure and seasonality are discussed.

Encontro de larvas de Anopheles (Nyssorhynchus) argyritarsis em criadouros artificiais no Estado de Mato Grosso / Anopheles (Nyssorhynchus) argyritarsis larvae found in artificial breeding sites in the State of Mato Grosso

Cita-se o encontro de formas imaturas de culicídeos em caixas d’água colocadas no nível do solo. Foram encontradas larvas de Anopheles argyritarsis e Aedes albopictus no município de Várzea Grande (MT). Considera-se que estes recipientes artificiais possam constituir locais adicionais utilizáveis como criadouros de anofelinos.

The finding of immature forms of culicid mosquitoes in water tanks at ground level is reported. Anopheles argyritarsis and Aedes albopictus were found in the municipality of Várzea Grande (MT). It is considered that these artificial containers may constitute additional locations that anophelines can use as breeding sites.