Limatus Durhami Research Articles

Species composition and abundance of mosquitoes (Diptera: Culicidae) in a green area surrounded by urbanization in the Neotropical megacity São Paulo, Brazil

The urbanization process can influence mosquito biodiversity and abundance, which in turn might affect public health. Here, we investigated mosquitoes’ abundance, diversity and seasonality in an urban green area, located in São Paulo, called Butantan Institute Park. We collected adult mosquitoes for two consecutive years by placing CDC light traps baited with CO2 in three different sites inside the park covering tree strata (canopy, understory and shrub layer). In total, we identified 27,350 mosquitoes belonging to nine different genera and 20 species, including several epidemiological important mosquito species that occupy the urban, sylvatic, and transitional ecotones. The most abundant species were Culex quinquefasciatus (Say, 1823) (Diptera: Culicidae) with 6,892 specimens collected, Culex nigripalpus (Theobald, 1901) (Diptera: Culicidae) with 5,878 and Limatus durhami (Theobald, 1907) (Diptera: Culicidae) with 4,615. While seasonality did not appear to be a strong factor shaping mosquito diversity and abundance, strata had a pronounced effect on the abundance of mosquitoes. The abundance and diversity (Shannon’s index) of mosquitoes was higher at ground level (shrub layer). The high presence of mosquitoes in the park increases the risk of enzootic cycles, re-emergence, or the emergence of new pathogens in the urban environment. For instance, we found one specimen of the genus Sabethes (Robineau-Desvoidy, 1827) indicating that monitoring is very important to prevent yellow fever outbreaks in São Paulo city. Finally, several aspects of mosquito biology and dispersion are discussed in more detail.

Mosquito species occurrence in association with landscape composition in green urban areas.

Aedes aegypti prefers densely populated habitats, but has been shown to explore less anthropogenic environments. We investigated composition of the abundance of mosquitoes in forested areas and assessed relationships between species occurrences and different types of land use and land cover at three spatial scales (100m, 500m and 1000m). Mosquitoes were collected from October 2012 to March 2013 using oviposition traps. We collected 4,179 mosquitoes in total including at least 10 species. Aedes albopictus and Limatus durhami were eudominant species, representing 90% of all collected individuals. We found intraspecific differences in response to land use and land cover, and species response patterns were similar at all spatial scales. Ae. albopictus relative abundance was associated with urbanized areas, while Li. durhami, Haemagogus leucocelaenus and Toxorhynchites sp., abundances were associated with native forest. Aedes aegypti were found in five of the eight areas studied, including in an Atlantic forest fragment at a considerable distance from the forest edge (370 m). Aedes aegypti occurrence was not influenced by type of land use or land cover.

Comparison of automatic traps to capture mosquitoes (Diptera: Culicidae) in rural areas in the tropical Atlantic rainforest

In several countries, surveillance of insect vectors is accomplished with automatic traps. This study addressed the performance of Mosquito Magnet® Independence (MMI) in comparison with those of CDC with CO2 and lactic acid (CDC-A) and CDC light trap (CDC-LT). The collection sites were in a rural region located in a fragment of secondary tropical Atlantic rainforest, southeastern Brazil. Limatus durhami and Limatus flavisetosus were the dominant species in the MMI, whereas Ochlerotatus scapularis was most abundant in CDC-A. Culex ribeirensis and Culex sacchettae were dominant species in the CDC-LT. Comparisons among traps were based on diversity indices. Results from the diversity analyses showed that the MMI captured a higher abundance of mosquitoes and that the species richness estimated with it was higher than with CDC-LT. Contrasting, difference between MMI and CDC-A was not statistically significant. Consequently, the latter trap seems to be both an alternative for the MMI and complementary to it for ecological studies and entomological surveillance.

Twenty-year surveillance of insects relevant to public health during the construction of hydroelectric facilities in Antioquia, Colombia

Human metapneumovirus is a newly discovered pathogen associated with respiratory disease and occurring mainly in children. It produces an acute viral respiratory disease picture that varies from mild disease to severe, and which can require strict surveillance in intensive care units. Currently, reverse transcriptase polymerase chain reaction and cell culture are the most common methods for its diagnosis. The first six cases of human metapneumovirus in Colombia are presented from Medellín.

New Records of Mosquitoes from Northwestern Argentina

Eleven mosquito species, namely Aedes hastatus, Ae. fulvus, Coquillettidia albicosta, Cq. juxtamansonia, Culex aliciae, Cx. delpontei, Cx. oedipus, Cx. pedroi, Mansonia flaveola, Uranotaenia leucoptera, and Wyeomyia oblita, are recorded for the first time from northwestern Argentina. In addition, 3 species, Cx. brethesi, Limatus durhami, and Ur. nataliae, are reported for the first time from Salta Province. These records extend the geographical distribution of these 3 species to Salta Province. This study also extends the geographical distributions of Cq. nigricans, Cx. chidesteri, and Ma. humeralis to Jujuy Province and of Ae. meprai, Ae. milleri, Ae. oligopistus, Cx. brethesi, Cx. fernandezi, and Cx. tatoi to Tucumán Province.

Vigilancia entomológica de insectos de importancia en salud pública durante la construcción de los proyectos hidroeléctricos Porce II y Porce III, Antioquia, Colombia, 1990-2009

Introduction. Entomological studies conducted in large hydroelectric infrastructure projects are a toolfor the prevention and control of vector-borne diseases. These diseases emerge as a consequence ofchanges made to the terrain that often increase the natural and artificial mosquito larval habitats. Many of these insects are of public health importance and population increases result in an increased risk ofdisease transmission. Objective. The culicine (mosquito) and phlebotomine (sand fly) populations were characterized in thearea of the Porce II and Porce III hydroelectric projects of Antioquia between 1990 to 2009. Materials and methods. Periodical entomological samplings were made in the area of impact, in theworkers camps, and construction sites. Adult specimens were captured with nets, Shannon light traps,CDC light traps, and protected human bait. Results. Mosquito larvae of the following species were identified: Culex coronator, Culex nigripalpus,Culex corniger, Culex quinquefasciatus and Limatus durhami. The most frequently identifiers of larvalhabitats were low tanks, waste cans, tires, and aquatic plants. Aedes aegypti specimens were capturedin only two rural locations from two municipalities within the area of influence. Specimens from thefollowing mosquito genera were captured in forest areas: Aedes, Mansonia, Culex, Psorophora,Wyeomyia, Phonyomyia, Uranotaenia, Haemagogus and Sabethes. The most important mosquitofound was Haemogogus janthinomis, an efficient yellow fever vector in Colombia. The area has beenendemic for leishmaniasis and in the current study, 20 species of Lutzomyia sand flies, potential vectors,were identified. Among malaria vectors, the most important species found in the area were Anophelesnuneztovari and Anopheles pseudopunctipennis. Conclusion. A wide variety of vectors were discovered in the area of the Porce II and Porce IIIhydroelectric projects, and many of these were relevant for public health. Further monitoring willbe necessary to minimize disease transmission risks among the workers and the inhabitants of thesurrounding areas. doi: http://dx.doi.org/10.7705/biomedica.v32i3.668

Immature Mosquitoes Of Serra Do Mar Park, São Paulo State, Brazil

With the objective of providing knowledge about the natural habitat of mosquito larvae, we conducted a study on the culicid fauna and identified larval habitat types at 3 different locations in the Serra do Mar State Park, Brazil, over the 12 months of 1991. We collected 1,425 larvae belonging to 23 species, of which the most frequent were Culex iridescens, Culex spp., Limatus durhami, and Trichoprosopon pallidiventer. The mosquito larval habitats presenting the greatest densities of specimens were bamboo, bromeliads, rubber boots, and streams. We observed that the culicids used a variety of containers as larval habitats and bred under a diversity of ecological conditions. Most of the habitats were natural, formed by bamboo, bromeliads, streams, and depressions in the ground and in rocks, along with artificial habitats consisting of rubber boots and abandoned metal cans. Seven species occurred preferentially in the internodes of closed bamboo stems, 6 in internodes of open stems, and 4 in bromeliads.

Seasonal Variation of Potential Flavivirus Vectors in an Urban Biological Reserve in Northeastern Brazil

Although yellow fever (YF) has not been reported on the eastern coast of Brazil since 1942, there was a reemergence of dengue fever in Brazil in 1987 due to the reintroduction of Aedes aegypti (L.). To assess areas of potential risk for transmission of vector-borne diseases, a surveillance system was placed in a large Atlantic Forest reserve in Natal, Rio Grande do Norte, Brazil, where in 2004 unexplained epizootics were reported among marmosets. The etiologic agent causing the mortality in marmosets has not been identified. Wyeomyia bourrouli Lutz, Haemagogus leucocelaenus Dyar & Shannon, Ae. aegypti, Aedes albopictus (Skuse), Ochlerotatus scapularis Rondani, Ochlerotatus serratus Theobald, Ochlerotatus taeniorhynchus Wiedemann, Culex quinquefasciatus Say, and Limatus durhami Theobald were collected in the park and in the proximity of the households adjacent to the park. Seasonal abundance fluctuation was significant for Ae. aegypti, Ae. albopictus, Ochlerotatus scapularis (Rondani), and Hg. leucocelaenus. Eggs of Ae. aegypti, Ae. albopictus, and Hg. leucocelaenus were more frequently found at the conclusion of the rainy season. A significant negative correlation between the number ofAe. albopictus collected and temperature was observed (r = -0.50), i.e., for each 10C increase in temperature, the number of specimens collected decreased eight-fold. The findings reported herein reinforce the need for a sustainable arboviral surveillance program in this area to decrease the potential risk of emergence of vector borne diseases as YF.

Imaturos de Culicidae (Diptera) encontrados em recipientes instalados em mata residual no munícipio de Londrina, Paraná, Brasil

Fragmentos de mata na área urbana ou periurbana podem ser locais favoráveis a procriação de Culicidae. Esse trabalho teve como objetivo levantar as espécies de culicídeos que utilizam criadouros artificiais, suas coexistência e as flutuações populacionais em uma reserva de mata localizada em Londrina - PR. Realizou-se coletas quinzenais de outubro de 1995 a setembro de 1996 em pneus e internódios de bambu armadilha que foram instalados ao nível do solo e outros internódios instalados a 2 m de altura. Coletou-se 12.656 espécimes, pertencentes a cinco gêneros e 11 espécies. As espécies mais abundantes nos criadouros foram Limatus durham Theobald, 1901, Culex eduardoi Casal & Garcia, 1968, Aedes terrens (Walker, 1856), Culex quinquefasciatus Say, 1823 e Aedes albopictus (Skuse, 1894). O maior número de indivíduos foi coletado em pneus, sendo que Limatus durham e Aedes terrens, apresentaram preferência nesse criadouro. A presença de Aedes aegypti (Linnaeus, 1762), Aedes albopictus e Haemagogus leucocelaenus (Dyar & Shannon, 1924) em diferentes coletas indica que esse tipo de ambiente não deve ser ignorado nas ações de controle de vetores, merecendo constante monitoramento.

Culicídeos associados a entrenós de bambu e bromélias, com ênfase em Aedes (Stegomyia) albopictus (Diptera, Culicidae) na Mata Atlântica, Paraná, Brasil

Aedes (Stegomyia) albopictus (Skuse, 1894) larvae were recorded for the first time in the internodes of bamboo cuts found in the Atlantic Forest in the State of Parana, Brazil. The bamboo, Bambusa sp., was introduced in the area of Imbucui-Mirim town, across the municipal district of Paranagua and towards the interior of the Atlantic Forest. A total of 251 larvae of Aedes albopictus (37.9%), Culex (Microculex) spp. (13.9%), Limatus durhami Theobald, 1901 (39.8%), Toxorhynchites sp. (0.4%) and Wyeomyia spp. (8.0%) were collected from bamboo internodes filled with rain and from the terrestrial Bromeliaceae and epiphytas found near the bamboo bushes. Aedes albopictus was found in bamboo internodes containing 30 to 254 ml of rain, sometimes coexisting with Li. durhami. Borders of forest ecosystems should be characterized as risk areas for arbovirosis transmission, since they sustain the circulation of vertebrates and arthropodal hematophagus, not only in the wild but also in the anthropic areas.

Imaturos de mosquito (Diptera, Culicidae) de áreas urbana e rural no norte do Estado do Paraná, Brasil

The results of larval collections of mosquitoes from artificial containers and natural breeding at urban and rural areas carried out at Sertaneja, northern State Parana, Brazil, from February to April, 1995, are presented. Among the 4534 immature forms collected, belonging to 21 species or species-groups, the species with higher density were Aedes aegypti (Linnaeus, 1762), Aedes albopictus (Skuse, 1894), Culex quinquefasciatus Say, 1823 and Limatus durhami Theobald, 1901.

Mosquitos (Diptera, Culicidae) das regiões de Pendotiba e oceânica de Niterói (Rio de Janeiro, Brasil)

Female mosquitoes (Culicidae) were collected in human bait weekly between March 1997 to February 1998, in three different areas of the oceanic region of Niteroi city, Rio de Janeiro State, in southeastern coast of Brazil. The results indicated the presence of 16 species: Anopheles aquasalis, Aedes scapularis, A. taeniorhynchus, A. albopictus, A. aegypti, Haemagogus leucocelaenus, Psorophora ferox, P. conffinis, P. cingulata, Culex quinquefasciatus, C. nigripalpus, Coquillettidia venezuelensis, Uranotaenia calosomata, Limatus durhami, Weyomyia oblita and Phoniomyia sp. A statistical analysis between monthly female frequencies and temperature, air humidity and precipitation monthly indices was done, using Sperman correlation in Statistica 4.2 program. The only difference among the collected points is the higher number of species collected in Engenho do Mato, in spite of the differences between them in relation to vegetal formation and conservation. The species showed higher frequencies of females during spring and summer seasons, and permit us to conclude that temperature and precipitation demonstrated high levels of correlation to female frequencies along the one year study, but the same was not observed in relation to air humidity. Some of the identified species, such as Aedes aegypti, A. albopictus, A. scapularis, Haemagogus leucocelaenus and Culex quinquefasciatus are important as disease vectors and control suggestions are made in front of the relative abundance of them in different periods of the year.

Atividades da estação biológica de Perús

The author who was appointed entomologist of the Biological Station in Perus, Sao Paulo, describes in this paper, the kind of work he has been doing there. He begins with a description of the organization of the Station and of the routine work as it was daily carried on there, by himself and his staff, during nearly 6 months. During the day as well as during the night, captures of jungle were made in the forest and the same was done by night, in the Station House chiefly when the athmosphere was damp, just before, during, or after a rain. There was also an intensive search for foci of mosquitoes' larves in the bromelias, in holes, in trees and in the soil. The larves found in these breeding places were brought to a larvarium established in the forest in a place close to the station where they were bred in holes of bambus which were very suitable for them. During daytime, only new hatched mosquitoes have been captured, but during the night it has been possible to catch, inside the Station house, many female mosquitoes, with developped eggs, so confirming Aragao's opinion, that mosquitoes biting during the day are always, newly hatched ones. Some species of Sabetini were captured only inside the Biological Station House, during the night. The habits of the following species were subjected to more accurate investigations. Aedes scapularis, Aedes leucocelaenus, Lutzia braziliae, Culex (Carolia) iridescens, Orthopodomyia albicosta, Goeldia palidiventer, Joblotia compressum, Wyeomyia longirostris, Sabetoides intermedius, Limatus durhami. The conditions of the temperature of the Station, did not permit the authour to obtain breedings of Aedes aegypti in the larvarium of the Station, even during he summer months. A great diminuitions of species of the jungle mosquitoes was observed, from January till June, that is, when temperature gets lower and lower. The author has made the interesting observation that some species of mosquitoes (Joblotia and Limatus), must take a meal of flowers or bee honey before they suck blood. A list of the mosquitoes captured during the months of February to June, in the Station is given.