Use of Aedes aegypti Oviposition Surveillance and a Geographic Information System for Planning Anti-Vectorial Measures.

Arboviruses transmitted by Aedes aegypti pose a threat to global public health. Because there are no vaccines or drugs available, the prevention of these diseases in Argentina is based on integrated vector control. In this work, the spatiotemporal dynamics of the vector distribution was analyzed by monitoring oviposition. This information allowed the planning of anti-vector interventions and the evaluation of their effect on the relative abundance of mosquito populations in San Ramón de la Nueva Orán. Observed data were compared with the eggs expected via a statistical model based on meteorological variables. The oviposition substrate preference of mosquito females was also evaluated, and the possible relationship between the relative abundance of the vector and sociodemographic and environmental variables (normalized difference vegetation index and normalized difference water index) was explored. A total of 4,193 eggs of Ae. aegypti were collected, and spatial clusters were detected for all months for which the presence of the mosquito was reported. The observed number of eggs was significantly less than the expected-corrected egg abundance. A significant correlation of oviposition activity was found with three sociodemographic variables, whereas no significant correlation was found with mean or median values of the environmental variables studied. This monitoring strategy made it possible to address the interventions and evaluate them, proposing them as good complementary tools for the control of Ae. aegypti in northern Argentina.

Redescription of immatures of Dasyhelea flavifrons Guérin-Méneville (Culicomorpha: Ceratopogonidae) and new contribution to the knowledge of its larval habitats.

The fourth instar larva and pupa of Dasyhelea flavifrons Guérin-Méneville are redescribed, illustrated, and photomicrographed using binocular, phase-contrast, and scanning electron microscopy. Comparisons with the American species of the grisea group were made. The immatures were collected by using a siphon bottle in tree-holes and from water collected in dead snail shells in Salta Province, Argentina, transported to the laboratory and there bred to the emergence of the adults. Details on larval habitats are given. These are the first records from Argentina and in gastrotelmata.

Vegetation Cover and Microspatial Distribution of Sand Flies (Diptera: Psychodidae) in an Endemic Locality for Cutaneous Leishmaniasis in Northern Argentina.

The sand fly fauna in Hipólito Yrigoyen, Argentina, a locality where cutaneous leishmaniasis cases occur, was surveyed with zones of higher abundance of sand flies correlated to vegetation cover estimated through normalized difference vegetation index (NDVI). Sand flies were collected with 10 CDC traps during six nights, from December 2009 to January 2010. A map was built of expected sand flies abundance in which levels of NDVI were categorized. In total, 1,392 Phlebotominae (Diptera: Psychodidae) specimens were collected, comprised of the following species: Nyssomyia neivai (Pinto 1926), Migonemyia migonei (França 1920), species of the cortelezzii complex (Brèthes 1923), Evandromyia sallesi (Galvão & Coutinho 1940), and Psathyromyia shannoni (Dyar 1929). Positive correlations were found between the abundance of sand flies and the NDVI (P < 0.05) for buffer areas of <150 m radii from the trap location points, i.e., the sand fly abundance was greater where vegetation cover and density were greater. In this context, plant cover should be taken into account to prioritize surveillance and control areas within the program of sand flies control in northern Argentina.

Factors Related to Aedes aegypti (Diptera: Culicidae) Populations and Temperature Determine Differences on Life-History Traits With Regional Implications in Disease Transmission.

Aedes aegypti (L.) (Diptera: Culicidae) is a vector of many medically significant viruses in the Americas, including dengue virus, chikungunya virus, and Zika virus. Traits such as longevity, fecundity, and feeding behavior contribute to the ability of Ae. aegypti to serve as a vector of these pathogens. Both local environmental factors and population genetics could contribute to variability in these traits. We performed a comparative study of Ae. aegypti populations from four geographically and environmentally distinct collection sites in Argentina in which the cohorts from each population were held at temperature values simulating a daily cycle, with an average of 25°C in order to identify the influence of population on life-history traits. In addition, we performed the study of the same populations held at a daily temperature cycle similar to that of the surveyed areas. According to the results, Aguaray is the most outstanding population, showing features that are important to achieve high fitness. Whereas La Plata gathers features consistent with low fitness. Iguazu was outstanding in blood-feeding rate while Posadas's population showed intermediate values. Our results also demonstrate that climate change could differentially affect unique populations, and that these differences have implications for the capacity for Ae. aegypti to act as vectors for medically important arboviruses.

Snail shells as larval habitat of Limatus durhamii (Diptera: Culicidae) in the Yungas of Argentina.

The shells of dead snails collect water from rainfalls producing aquatic microenvironments called gastrotelmata. These habitats are small and hold simple detritus based on animal communities, being rotifers and culicids the most studied. Although a high diversity of aquatic microhabitats has been reported as larval habitats of mosquitoes in Argentina, the shell of snails has not been investigated yet. We report the shells of three species of native Megalobulimus genus as larval habitats of a neotropical mosquito and suspected vector of bunyaviruses, Limatus durhamii, and describe these microhabitats in the Yungas forest of Argentina.

Notes on the occurrence and habitats of Sabethes purpureus in Salta Province, Argentina.

The finding of Sabethes purpureus larvae and pupae in tree holes both in urban and forest environments in San Ramón de la Nueva Orán, Salta Province, Argentina, is reported, together with information on the larval habitat. Tree holes were sampled monthly from January to March or April of 2011, 2012, and 2013 along sidewalks, in public access areas, and in 3 sites within forested areas outside the city, selected along an urban gradient in Orán. Sabathes purpureus was most frequently found in low numbers and with other mosquito species. A higher proportion of tree holes was positive in the urban compared to the forest environment, although there were no significant differences in abundances or densities per hole. To our best knowledge, this paper reports the species for the first time breeding in an urban environment, and extends its geographical distribution from the Atlantic and Paranaense forests to the Southern Andean Yungas in northwestern Argentina.