Mosquitos da Caatinga: biodiversidade, aspectos ecológicos e importância epidemiológica da fauna Culicidae do semiárido brasileiro / Mosquitoes of the Caatinga biodiversity, ecology and epidemiological importance of Culicidae fauna of the Brazilian semiarid

Em relação à fauna Culicidae, a Caatinga é um dos biomas mais desconhecidos do Brasil. Há carência de registro de ocorrência de culicídeos, bem como de estudos sobre as interações deles com o ambiente silvestre. Assim, o objetivo deste estudo foi investigar biodiversidade e aspectos ecológicos e epidemiológicos da fauna Culicidae em áreas de conservação do bioma Caatinga. Para isso foram consideradas duas unidades de conservação da Caatinga e realizados 19 levantamentos entomológicos mensais e consecutivos. Foram realizadas coletas de formas imaturas de mosquitos em bromélias, ocos de árvore e criadouros de solo, além da coleta de mosquitos adultos de hábitos diurno, crepuscular e noturno. Ao todo, entre mosquitos adultos e imaturos associados a habitats fitotelmatas, foram coletados 11.456 culicídeos distribuídos em 28 espécies, das quais 11 eram desconhecidas para a ciência. A fauna de imaturos coletados em bromélias e ocos de árvore interferiu na composição da fauna de mosquitos adultos e houve variações na abundância e nos padrões de diversidade de acordo com fitofisionomia do ambiente. Temperatura e umidade foram os parâmetros ambientais mais fortemente associados à abundância de culicídeos. Foram registradas novas ocorrências de anofelinos, coletados em criadouros de solo, ampliando a distribuição das espécies para o semiárido brasileiro

Regarding Culicidae fauna, Caatinga is one of the most unknown biomes of Brazil. There are few records of mosquitoes occurrence, as well as studies on their interactions with the wild environment. Therefore, the aimof this study was to investigate the biodiversity, ecological and epidemiological aspects of Culicidae fauna in conservation areas of the Caatinga biome. Two protected areas were considered for the study and 19 entomological surveys were performed monthly. Immature forms of mosquitoes were collected in bromeliads, tree holes and ground pools, as well as collection of adult mosquitoes with day time, twilight and nocturnal habits. Between adults and immatures associated with phytotelmatas habits, a total of 11,456 mosquitoes were collected, distributed in 28 species, 11 of which were unknown to science. The immature fauna collected in bromeliads and tree holes interfered in the fauna composition of adults and there were variations in the abundance and diversity patterns according to the environment phytophysiognomy. Temperature and humidity were the most strongly environmental factors associated with the abundance of mosquitoes. New records of anophelines collected inground pools were registered, broadening the distribution of species in the Brazilian semiarid region

Presencia larval de anopheles albimanus (Diptera: Culicidae) en La Habana, Cuba 2010-2012 / Larval presence of anopheles albimanus (Diptera: Culicidae) in Havana, Cuba, 2010-2012

INTRODUCCIÓN: Anopheles albimanus es el principal vector de la malaria en Cuba, éste también se encuentra distribuido en varios países del continente americano. OBJETIVO: determinar la presencia larval de An. albimanus en la provincia de La Habana durante 2010-2012. MÉTODOS: el muestreo se llevó a cabo con una frecuencia semanal en el período 2010-2012. Los sitios de cría encuestados fueron clasificados como naturales permanentes y temporales así como depósitos artificiales. RESULTADOS: se registra la presencia de An. albimanus en 9 (60,0 por ciento) del total de los municipios muestreados en el 2010 y en 12 (80 por ciento) en los años 2011 y 2012. Los municipios que no lo registraron en los tres años fueron Centro Habana, Plaza de la Revolución y Habana Vieja. La provincia obtuvo un promedio de 1173,8 y 97,7 muestras larvales de ésta especie por año y por mes respectivamente. El municipio Boyeros mostró un promedio de muestras de 922,6 por año y 76,8 por mes siendo el que mantiene la mejor vigilancia sobre An. albimanus. Los sitios de cría con mayor presencia de An. albimanus correspondieron al grupo de naturales permanentes destacándose las zanjas y lagunas naturales, además se encontraron criaderos en 26 tipos diferentes de depósitos artificiales. A partir de mayo ocurre un incremento del número de muestras hasta octubre. CONCLUSIONES: se encontró presencia larval de An. albimanus en la mayoría de los municipios durante todo el año; por lo que mantener un constante monitoreo sobre la especie debe ser una prioridad en la vigilancia de la malaria en La Habana(AU)

INTRODUCTION: Anopheles albimanus is the main malaria vector in Cuba. It is also distributed in several countries in the Americas. OBJECTIVE: determine the larval presence of An. albimanus in the province of Havana in the period 2010-2012. METHODS: sampling was conducted on a weekly basis during the period 2010-2012. The breeding sites surveyed were classified as natural permanent, natural temporary and artificial containers. RESULTS: presence of An. albimanus was reported in 9 (60.0 percent) of the municipalities sampled in 2010 and 12 (80 percent) of those sampled in 2011 and 2012. The municipalities of Centro Habana, Plaza de la Revolución and Habana Vieja did not report any larval presence of An. albimanus in any of the three years. The province had an average 1 173.8 and 97.7 larval samples per year and month, respectively. In the municipality of Boyeros, the average was 922.6 per year and 76.8 percent month. This is the municipality with the best surveillance of An. albimanus. The greatest presence of An. albimanus was found in natural permanent breeding sites, particularly ditches and natural ponds. Breeding sites were also found in 26 different types of artificial containers. An increase in the number of samples was observed from May to October. CONCLUSIONS: larval presence of An. albimanus was found in most municipalities throughout the year. Therefore, permanent monitoring of the species should be a priority of malaria surveillance in Havana(AU)

Occurrence of immature forms of culicids (Insecta: Diptera) in the northeastern region of Brazil / Ocorrência de formas imaturas de culicídeos (Insecta: Diptera) na região nordeste do Brasil

The Culicidae family is represented by approximately 3,610 species, among which many are involved in transmission of pathogens and parasites, thus presenting great medical-veterinary importance. In Brazil, the state of Pernambuco is considered an endemic area for many diseases vectored by mosquitoes, such as human and canine filariasis, caused by Wuchereria bancrofti and Dirofilaria immitis, respectively. The aim of this study was to evaluate the occurrence of immature forms of culicids, over an one-year period, in a specific area of northeastern region of Brazil. Culicids larvae were collected from traps located on the ground and in treetops, between october 2012 and september 2013. Ten different species of culicids were identified. The greatest number of larvae were collected in september 2013 and the lowest number in december 2012. Stegomyia (Stegomyia) albopicta (46.45%; 5,908/12,718), Culex (Culex) maxi (35.56%; 4,523/12,718) and Limatus durhamii (12.58%; 1,600/12,718) were the most frequent species. The human and animal populations living in the study area are exposed to culicids and transmission agents throughout the year, especially after the rains. Therefore, control and prevention measures against culicids must be adopted in the study area.

A família Culicidae é representada por aproximadamente 3.610 espécies, dentre as quais muitas estão envolvidas na transmissão de patógenos e parasitos, apresentando assim grande importância médico-veterinária. No Brasil, o Estado de Pernambuco é considerado área endêmica para diversas doenças transmitidas por mosquitos como, por exemplo, as filarioses humana e canina causadas pela Wuchereria bancrofti e Dirofilaria immitis, respectivamente. O objetivo deste estudo foi avaliar a ocorrência de formas imaturas de culicídeos durante um ano em uma área do Nordeste do Brasil. Larvas de culicídeos foram coletadas em armadilhas localizadas no solo e copa de árvores, no período de outubro de 2012 a setembro de 2013. Dez diferentes espécies de culicídeos foram identificadas, sendo o maior número de larvas coletadas em setembro de 2013 e o menor número em dezembro de 2012. Stegomyia (Stegomyia) albopicta (46,45%; 5.908/12.718), Culex (Culex) maxi (35,56%; 4.523/12.718) e Limatus durhamii (12,58%; 1.600/12.718) foram as espécies mais frequentes. A população humana e animal residente na área de estudo é exposta aos culicídeos e aos agentes por eles veiculados durante todo o ano, sobretudo após o período de chuvas. Portanto, medidas de controle e prevenção dos culicídeos devem ser adotadas na área estudada.

Dos nuevos registros de vectores potenciales de Fiebre Amarilla selvática y Mayaro para el Ecuador / Two new records of potential Sylvan Yellow Fever and Mayaro species vectors from Ecuador

Se registran por primera vez en el Ecuador dos especies de mosquitos (Diptera: Culicidae), vectores potenciales de los virus de la Fiebre Amarilla y Mayaro. Sabethes amazonicus Gordon and Evans y Haemagogus anastasionis Dyar fueron colectados en fase adulta en una localidad de la provincia de Zamora-Chinchipe, en la cual se han presentado casos de Fiebre Amarilla selvática con anterioridad. Este hallazgo muestra la importancia de profundizar los estudios de linea base de vectores en el país, distribución geográfica y aspectos ecológicos y su posible relación epidemiológica con enfermedades emergentes y re-emergentes.

Two new records of mosquitoes (Diptera: Culicidae) are presented from Ecuador, and both potential vectors of yellow fever virus and Mayaro. Sabethes amazonicus Gordon and Evans and Haemagogus anastasionis Dyar adults were collected in a locality in the province of Zamora-Chinchipe, in which there have been cases of yellow fever previously. This finding shows the importance of further studies of baseline vector in the country, geographical distribution and ecological aspects and possible epidemiological link with emerging and re-emerging diseases.

Vigilancia de insectos de importancia en salud pública durante la construcción de los proyectos hidroeléctricos Porce II y Porce III, Antioquia, Colombia, 1990-2009 / Twenty-year surveillance of insects relevant to public health during the construction of hydroelectric facilities in Antioquia, Colombia

Introducción. Los estudios entomológicos en las grandes obras de infraestructura hidroeléctrica constituyen una herramienta para la prevención y el control de enfermedades transmitidas por vectores, debido a que con frecuencia las alteraciones causadas en el medio producen aumento de criaderos naturales y artificiales en el área de influencia y, por ende, incremento de las poblaciones de artrópodos, entre ellos, insectos de interés en salud pública. Objetivo. Realizar estudio y vigilancia de la fauna de Culicidaey Phlebotominae en el área de los proyectos hidroeléctricos Porce II y Porce III, 1990-2009. Materiales y metódos. Se realizaron muestreos entomológicos periódicos para la vigilancia en salud pública de las comunidades ubicadas en el área de influencia y en campamentos y frentes de obra. Los adultos fueron capturados con red para mariposas, trampas de luz Shannon y CDC, y cebo humano protegido. Resultados. Se encontraron larvas de mosquitos de Culex coronator, Cx. nigripalpus, Cx. corniger, Cx. quinquefasciatus y Limatus durhami. Los depósitos más frecuentes fueron: tanques bajos, canecas, llantas y matas sembradas en agua. Aedes aegypti solo fue capturado en dos localidades rurales de dos municipios del área de influencia. En las zonas de bosque se capturaron mosquitos Aedes, Mansonia, Culex, Psorophora, Wyeomyia, Phonyomyia, Uranotaenia, Haemagogus y Sabethes; el principal fue Haemogogus janthinomis, eficiente vector de fiebre amarilla en Colombia. La zona es endémica para leishmaniasis y se identificaron 20 especies de Lutzomyia. Entre los vectores de malaria, las principales especies encontradas fueron Anopheles nuñeztovari y An. pseudopunctipennis. Conclusión. En la zona de Porce II y Porce III existe diversidad de vectores de importancia en salud pública, que es necesario continuar vigilando para minimizar el riesgo de transmisión de enfermedades a los trabajadores de las obras y comunidades aledañas.

Introduction. Entomological studies conducted in large hydroelectric infrastructure projects are a tool for the prevention and control of vector-borne diseases. These diseases emerge as a consequence of changes 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 of disease transmission. Objective. The culicine (mosquito) and phlebotomine (sand fly) populations were characterized in the area 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 the workers 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 larval habitats were low tanks, waste cans, tires, and aquatic plants. Aedes aegypti specimens were captured in only two rural locations from two municipalities within the area of influence. Specimens from the following mosquito genera were captured in forest areas: Aedes, Mansonia, Culex, Psorophora, Wyeomyia, Phonyomyia, Uranotaenia, Haemagogus and Sabethes. The most important mosquito found was Haemogogus janthinomis, an efficient yellow fever vector in Colombia. The area has been endemic 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 Anopheles nuneztovari and Anopheles pseudopunctipennis. Conclusion. A wide variety of vectors were discovered in the area of the Porce II and Porce III hydroelectric projects, and many of these were relevant for public health. Further monitoring will be necessary to minimize disease transmission risks among the workers and the inhabitants of the surrounding areas.

Changes in the fat body during the post-embryonic development of the predator Toxorhynchites theobaldi (Dyar & Knab) (Diptera: Culicidae)

Several studies have focused on understanding the biochemistry and morphology of the fat body of the hematophagous mosquito Aedes aegypti (L.) (Diptera: Culicidae). In contrast, few studies, if any, have focused on morphological characters of the fat body in other mosquitoes, especially non-hematophagous taxa such as the culicid Toxorhynchites. Larvae of Toxorhynchites prey upon the larvae of other mosquito species and are used in vector mosquito control. We investigated aspects of the fat body trophocytes, including the morphometric analyses of the lipid droplets, protein granules and nuclei, during Toxorhynchites theobaldi (Dyar & Knab) post-embryonic development. Following the body weight increase from larval stage L2 to L4, the size of lipid droplets within the trophocytes also increase, and are likely the result of lipogenesis. Lipid droplets decrease in size during L4 to the female pupal stage and increase once again during the period from newly-emerged to mature adult females. Protein granules are observed for the first time in female pupae, and their appearance might be related to protein storage during metamorphosis. The size of the nucleus of trophocytes also increases during larval development, followed by a decrease during metamorphosis and an additional increase as adult female ages. In conclusion, the morphology of the fat body of T. theobaldi changes according to the developmental stage. Our study provides for the first time important insights into T. theobaldi fat body development and contributes to understand this species biology.

Presença de mosquitos (Diptera: Culicidae) em piscinões na zona leste de São Paulo / The presence of mosquitoes (Diptera: Culicidae) in flood containment reservoirs in the eastern region of the City of São Paulo, Brazil

INTRODUÇÃO: Alterações no ambiente vêm contribuindo com mudanças climáticas, como o aumento do volume de chuvas, que acarreta as inundações. Medidas estão sendo tomadas no enfrentamento das inundações, como a implantação dos reservatórios de contenção de cheias (piscinões). Neste trabalho, foi avaliada a fauna de culicídeos, de importância epidemiológica, nos piscinões Caguaçu e Inhumas. MÉTODOS: Foram realizadas coletas mensais nos piscinões Caguaçu e Inhumas, situados na região leste de São Paulo, de março de 2006 a fevereiro de 2007, empregando-se os métodos de concha entomológica e aspirador. Para análise dos dados, foram realizadas análises estatísticas descritivas e a regressão linear simples. RESULTADOS: Foram coletados 8.917 culicídeos, destacando-se Culex (Culex) quinquefasciatus, que representou 98,9% dos espécimes no Inhumas e 95,2% no Caguaçu. No Caguaçu, a maior frequência de imaturos foi observada no vertedouro (61%) e no Inhumas na canaleta (42,6%). A precipitação prediz 87% da abundância numérica de larvas de terceiro e de quarto estágio no Caguaçu e 60% do número de pupas coletadas. No Inhumas, a precipitação explicou 36% da abundância numérica de larvas e 18% do número de pupas. CONCLUSÕES: Culex quinquefasciatus, vetor de agentes da filariose, arboviroses e fator de incômodo à população, foi a espécie mais frequente nos dois ambientes. Medidas de controle da espécie nos piscinões estudados se fazem necessárias tendo em vista seu potencial epidemiológico.

INTRODUCTION: Alterations in the environment contribute to changes in weather patterns, which cause an increase in rainfall, which causes flooding. Flooding has been addressed by building reservoirs, called piscinões, to contain the excess rain. In this report, we evaluated the Culicidae fauna of epidemiological importance in the reservoirs of Caguaçu and Inhumas. METHODS: Monthly collections were performed in both reservoirs, which are situated in the Eastern section of the City of São Paulo. Monthly collections of Culicidae were undertaken using the entomological scoop method and a battery aspirator during the period between March 2006 and February 2007. Descriptive statistical and simple linear regression analyses of the data were carried out. RESULTS: A total of 8,917 Culicidae mosquitoes were collected. The majority of the insects captured were of Culex (Culex) quinquefasciatus, representing 98.9% of the specimens identified in the Inhumas and 95.2% of those identified in Caguaçu. In the Caguaçu reservoir, the greatest frequency of immature mosquitoes was observed in the spillway (61%). In the Inhumas reservoir, the greatest occurrence of immature Culicidae was detected in the channel (42.6%). The linear regression analysis showed that 87% of the larvae in the third and fourth stages and 60% of the pupae were collected during periods of rainfall. In the Inhumas reservoir, 36% of the larvae and 18% of the pupae were collected during periods of rainfall. CONCLUSIONS: Culex quinquefasciatus, a vector for agents of filariasis and arbovirus diseases and a nuisance to the human population, was frequent in both environments. Methods of control of the species in the studied dams are necessary to reduce their epidemiological potential.

New report on the bionomics of Coquillettidia venezuelensis in temporary breeding sites (Diptera: Culicidae) / Novo relato sobre a bionomia de Coquillettidia venezuelensis em criadouros temporários (Diptera: Culicidae)

INTRODUCTION: Findings of immature forms of Coquillettidia venezuelensis in temporary breeding sites, without the presence of aquatic plants or other submerged plant tissue are reported. METHODS: A systematic scooping technique to collect specimens was used at the breeding site. RESULTS: Immature forms of Coquillettidia venezuelensis, Anopheles rangeli, An. evansae and Culex sp. were collected from areas of the hydroelectric power station of São Salvador, State of Goiás. CONCLUSIONS This is a novel finding relating to the bioecology of Cq. venezuelensis, a species of medical interest that has been found naturally infected with arboviruses, including Oropouche and West Nile virus.

INTRODUÇÃO: Relata-se o encontro de formas imaturas de Coquillettidia venezuelensis em criadouros temporários, sem presença de plantas aquáticas ou outros tecidos vegetais submersos. MÉTODOS: Realizaram-se coletas com a técnica de conchadas sistemáticas na margem do criadouro. RESULTADOS: Foram coletados imaturos de Coquillettidia venezuelensis, Anopheles rangeli, An. evansae e Culex sp., em áreas da Usina Hidrelétrica de São Salvador, Estado de Goiás. CONCLUSÕES: Trata-se de observação inédita sobre a bioecologia de Cq. venezuelensis, espécie de interesse médico, que tem sido encontrada naturalmente infectada com arbovírus, inclusive Oropouche e West Nile.

Geographical distribution and relative abundance of culicine mosquitoes in relation to transmission of lymphatic filariasis in El Menoufia Governorate, Egypt

Culicine mosquito were surveyed in El Menoufia Governorate [October to November 2008 and April to May 2009] in villages representing eight districts. Six species were reported: Culex [Culex] pipiens Linnaeus, Cx. [Cx] perexiguus Theobald, Cx. [Cx.] antennatus [Becker], Aedes [Ochlerotatus] caspius [Pallas], Aedes [Ochlerotatus] detritus [Haliday] and Culiseta [Allotheobaldia] longiareolata [Macquart]. Cx. pipiens, the main filariasis vector was the commonest or predominating species [ca. 47% adults and 92% larvae, P<0.01]. For the common species, the following were investigated: 1-temperature and pH of the breeding habitats and their relation to the larval density and 2-relation of adult indoor density with indoor-and outdoor-temperature and RH. Besides, parasitologically, Wuchereria bancrofti cases [33/631 blood samples, 5.23%] were detected in three districts [range=1.96-14.12% infection]. The cases were associated with the abundance of Cx. pipiens adults [ca. 45-62% of the collected adults]

Is global warming likely to cause an increased incidence of malaria?

The rise in the average temperature of earth has been described as global warming which is mainly attributed to the increasing phenomenon of the greenhouse effect. It is believed that global warming can have several harmful effects on human health, both directly and indirectly. Since malaria is greatly influenced by climatic conditions because of its direct relationship with the mosquito population, it is widely assumed that its incidence is likely to increase in a future warmer world.This review article discusses the two contradictory views regarding the association of global warming with an increased incidence of malaria. On one hand, there are many who believe that there is a strong association between the recent increase in malaria incidence and global warming. They predict that as global warming continues, malaria is set to spread in locations where previously it was limited, due to cooler climate. On the other hand, several theories have been put forward which are quite contrary to this prediction. There are multiple other factors which are accountable for the recent upsurge of malaria: for example drug resistance, mosquito control programs, public health facilities, and living standards

Field evaluation of novaluron, a chitin synthesis inhibitor larvicide, against mosquito larvae in polluted water in urban areas of Bangkok, Thailand.

Novaluron, an insect growth regulator, a benzoylphenyl urea insecticide, was evaluated in the field against the larvae of polluted-water mosquitoes. The study was carried out in highly polluted sites infested with populations of mosquito larvae, mostly Culex quinquefasciatus Say, in low-income communities in urban areas of Bangkok, Thailand. An EC10 formulation was premixed in water and applied by pressurized spray tank to plots ranging from 180 to 1,000 m2 at the rate of 0.1 ml EC 10/m2 (equal to 10 mg a.i./m2) of the breeding sites. Assessments were made by sampling mosquito larvae and pupae to determine the trends of immature populations before treatment and weekly after treatment. Reduction of the populations in percents were then computed by comparing counts of immature mosquitoes (larvae and pupae) to the pretreatment counts at each particular site. It was found that the immature populations of mosquitoes in the treated areas were dramatically suppressed and remained at extremely low levels for 3-7 weeks after the treatment depending on the prevailing conditions of each experimental site. No negative impact on fishes or aquatic plants in the treated areas were detected during the study period and three months after the experiment was discontinued. Novaluron is an effective agent to control immature populations of polluted-water mosquitoes, especially Cx. quinquefasciatus in habitats in urban areas. This IGR larvicide may play an important role in vector control programs in terms of effectiveness, environmental friendliness and strategies for insecticide-resistance management in vector mosquitoes.

Potential association of dengue hemorrhagic fever incidence and remote senses land surface temperature, Thailand, 1998.

A pilot study was designed to analyze a potential association between dengue hemorrhagic fever (DHF) incidence and, temperature computed by satellite. DHF is a mosquito transmitted disease, and water vapor and humidity are known to have a positive effect on mosquito life by increasing survival time and shortening the development cycle. Among other available satellite data, Land Surface Temperature (LST) was chosen as an indicator that combined radiated earth temperature and atmospheric water vapor concentration. Monthly DHF incidence was recorded by province during the 1998 epidemic and obtained as a weekly combined report available from the National Ministry of Public Health. Conversely, LST was calculated using remotely sensed data obtained from thermal infrared sensors of NOAA satellites and computed on a provincial scale. Out of nine selected study provinces, five (58.3%) exhibited an LST with a significant positive correlation with rainfall (p < 0.05). In four out of nineteen surveyed provinces (21.3%), LST showed a significant positive correlation with DHF incidence (p < 0.05). Positive association between LST and DHF incidence was significantly correlated in 75% of the cases during non-epidemic months, while no correlation was found during epidemic months. Non-climatic factors are supposed to be at the origin of this discrepancy between seasonality in climate (LST) and DHF incidence during epidemics.

Distribución vertical de haemagogus janthinomys (dyar) (diptera: culicidae) en bosques de la amazonía peruana / Vertical distribution of the mosquito Haemagogus jantinomys (Dyar) (Diptera: Culicidae) in forests of the Peruvian Amazon

Objetivos: Determinar si la abundancia del mosquito Haemagogus janthinomys está relacionada con la temperatura y lahumedad relativa, y si varía entre el dosel y el sotobosque en tres tipos de bosques de la selva Amazónica, medido porcebo humano. Materiales y métodos: Se colectó Hg. janthinomys al mismo tiempo en dos estratos de tres sitios en trestipos de bosques -bosque que se desarrolla sobre suelo arcilloso, sobre arena blanca (varillal), y bosques inundables(bajiales) cerca de Iquitos, Perú. Se midió la temperatura y la humedad relativa cada 15 minutos durante el tiempo decolecta. Resultados: No se encontró Hg. janthinomys en los bajiales mostrados. Su abundancia fue igual en el montealto que en los varillales (Z = 1, 48; p = 0,14), pero fue mayor en el dosel (2,9; ± 0,89) que en el sotobosque (0,4; ±0.23) (Z = 2,80; p = 0,005). No se encontró una relación entre la abundancia de Hg. janthinomys y la temperatura y lahumedad relativa (F1, 14 < 0,33; p > 0057; r2 < 0,03). Conclusiones: Estos resultados preliminares indican que alrededorde Iquitos, como en otras regiones, Hg. janthinomys es más abundante en el dosel. También, los resultados sugieren quela probabilidad de encontrar Hg. janthinomys puede depender del tipo de bosque en la selva amazónica peruana, perono depende en la variación de la temperatura ni la humedad relativa que es típica para los bosques tropicales.

Objectives: Our goals were to determine if the abundance of the mosquito Haemagogus janthinomys is correlated with environmental variables, and if it differs between the canopy and understory in three different Amazonian forest types. Materials and methods: Adult Hg. janthinomys mosquitoes were collected via human landings simultaneously in the canopy and understory of three replicate high forest, white sand forest, and seasonally flooded forest sites near Iquitos, Peru. Temperature and relative humidity were recorded every 15 min. during the collection periods. Results: No Hg. janthinomys were collected in seasonally flooded forest. Their abundance was similar between high forest and white sand forest (Z = 1, 48; p = 0,14), but more individuals were encountered in the canopy (2.9; ± 0.89) than in the understory (0,4; ± 0.23) (Z = 2.80; p = 0,005). Hg. janthinomys abundance was not correlated with temperature or humidity (F1, 14 < 0.33; p > 0057; r2 < 0.03). Conclusions: These preliminary results show that around Iquitos as in other regions, Hg. janthinomys are most abundant in the forest canopy. They also suggest that the probability of encountering Hg. janthinomys it can depends both on forest type and height of sampling within forests, but is not a function of temperature and humidity within the ranges commonly encountered in tropical forests.

Aspectos da distribuição de Culex (Culex) quinquefasciatus Say (Diptera, Culicidae) na região do rio Pinheiros, na cidade de São Paulo, Estado de São Paulo, Brasil / Aspects of the distribution of Culex (Culex) quinquefasciatus Say (Diptera, Culicidae) in the region of the Pinheiros River, in the city of São Paulo, State of São Paulo, Brazil

A distribuição de Culex (Culex) quinquefasciatus Say (1823) ao longo das margens do rio Pinheiros e os principais fatores que levam à proliferação da espécie foram estudados efetuando-se coletas semanais de mosquitos adultos, no período de um ano, em três pontos eqüidistantes às margens do rio. Para as coletas de mosquitos utilizou-se aspirador à bateria, por um período de cinco minutos. Os mosquitos foram identificados, diferenciados segundo o sexo e contados. Para verificação do estado fisiológico, as fêmeas foram separadas em vazias, com sangue e com ovos. Foram coletados 35.684 mosquitos, todos identificados como Cx. quinquefasciatus, sendo 39,4 por cento fêmeas e 60,6 por cento machos. As freqüências tomaram proporções diferentes entre os pontos de coletas e, em uma série temporal. O ambiente impactado do rio Pinheiros representa um excelente criadouro de Cx. quinquefasciatus, confirmado pela ocorrência de picos acentuados na freqüência de mosquitos, com desenvolvimento de forma explosiva e sobreposições entre as gerações, após as chuvas e em épocas de verão.

The distribution of Culex (Culex) quinquefasciatus Say (1823) along of the margins of the Pinheiros river and the main factors that lead to the proliferation of the species were studied doing weekly collections of adult mosquitoes, in the period of one year, in three equidistant points in the margins of the river. For the collections of mosquitoes battery vacuum cleaner was used, for a period of five minutes. The mosquitoes were identified, differentiated according to the sex and counted. For verification of the physiological state, the females were differentiated in empty, with blood or eggs. A total of 35.684 mosquitoes were captured, all of them were identified as Cx. quinquefasciatus, being 39.4 percent females and 60.6 percent males. The frequencies took different proportions between the points of collections and in a temporary series. The damaged environment of the Pinheiros river represents an excellent breeding site of Cx. quinquefasciatus, confirmed by the occurrence of picks accentuated in the frequency of mosquitoes, with development in an explosive way and accumulation between the generations, after the rains and in summer times.

The relationship between the abundance of Mansonia mosquitoes inhabiting a peat swamp forest and remotely sensed data.

The present study aimed to demonstrate the relationship of some environmental factors, vegetation greenness index (NDVI) and land surface temperature (LST), with the seasonal variations of Mansonia bonneae and Ma. uniformis in Khosit Subdistrict, Narathiwat Province. It was found that the Mansonia population lagged one month behind but correlated positively to NDVI, LST and rainfall. A rise in the number of mosquitoes was directly related to a rise in vegetation, temperature and rainfall.

Bionomics studies of Mansonia mosquitoes inhabiting the peat swamp forest.

The present study was conducted in the years 2000-2002 to determine the bionomics of Mansonia mosquitoes, vectors of nocturnally subperiodic Brugia malayi, inhabiting the peat swamp forest, "Phru Toh Daeng", Narathiwat Province, Thailand. Fifty-four species of mosquitoes belonging to 12 genera were added, for the first time, to the list of animal fauna in the peat swamp forest. Mansonia mosquitoes were the most abundant (60-70%) by all collection methods and occurred throughout the year with a high biting density (10.5-57.8 bites per person-hour). Ma. bonneae was most prevalent (47.5%) and fed on a variety of animal hosts, including domestic cats, cows, monkeys, and man with a maximum biting density of 24.3 bites per person-hour in October. The infective bites were found for the first time in Ma. annulata collected at Ban Toh Daeng (13 00-14 00 hours) and also Ma. bonneae at forest shade (16 00-17 00 hours) and in a village (20 00-21 00 hours) with rates of 0.6, 1.1 and 1.0%, respectively. The biting activities of these two species occurred in both the day and night time, with two lower peaks at 10 00 hours (18.5 bites per person-hour) and 13 00-15 00 (8.5-10.0 bites per person-hour) hours, but the highest peak was 19 00-21 00 hours (31.5-33.0 bites per person-hour) The biting activity patterns corresponded with the periodicity found in man and domestic cats and may play an important role in either transmission or maintenance of the filarial parasites in the peat swamp forest. The relative role of Ma. bonneae and Ma. uniformis in different environmental settings (primary swamp forest and open swamp) on the transmission of nocturnally subperiodic B. malayi merits further study.

Surveys for natural host plants of Mansonia mosquitoes inhabiting Toh Daeng peat swamp forest, Narathiwat Province, Thailand.

Surveys were carried out monthly from April-October 2002 to examine 68 sampling sites around "Toh Daeng" peat swamp forest in Narathiwat Province, Thailand, of which 38 were known Mansonia-positive habitats and 30 were Mansonia-negative sites. The present larval surveys were qualitative owing to features of the host plants (location, distribution, and abundance), difficulties in locating and selecting the host plants in the swamp forest, and time constraints. Twenty attempts were made for each species for larvae. The presence of Mansonia larvae on each plant species was confirmed 6 times for each plant and location. Larvae of Ma. bonneae and Ma. uniformis were obtained from 18 plant species (10 families): Metroxylon sagu, Melaleuca cajuputi, Pandanus militaris, Pandanus immerses, Hanguana malayana, Typha angustifolia, Hymenachne acutigluma, Scirpodendron ghaeri, Scleria sumatrensis, Rhynchospora corymnosa, Sacclolepis indica, Cyperus babakan, Cyperus corymbosus, Lepironia articulata, Leersia hexandra, Eichhornia crassipes, Pistia stratriotes and ferns. The emergent grasses, S. ghaeri, S. sumatrensis, H. acutigluma, R. corymnosa, S. indica, C. babakan, C. corymbosus, and L. articulata, were the preferred host plants. Samples from larger trees, M. sagu and M. cajuputi, yielded low numbers of 1-7 larvae per scraping. Ma. uniformis was recovered from most of the host plants, while Ma. bonneae preferred submerged plants and was not found on the floating aquatic plants, E. crassipes and P. stratriotes. The description of modified dipper and dipping techniques are given and discussed.

Aspectos ecológicos da populacão de Culex quinquefasciatus Say (Diptera, Culicidae) em abrigos situados no Parque Ecológico do Tietê, São Paulo, SP / Ecological aspects of Culex quinquefasciatus Say (Diptera, Culicidae) adult population in shelters at the Parque Ecológico do Tietê, São Paulo, SP

O estudo objetivou conhecer, ao longo das estacões do ano, aspectos ecológicos da populacão adulta de Culex quinquefasciatus em abrigos. As coletas dos adultos foram realizadas mensalmente, cobrindo-se o período de um ano, na vegetacão da margem de um canal de circunvalacão. Os insetos foram capturados com o auxílio de um aspirador à bateria. O material foi acondicionado e transportado ao laboratório e, posteriormente, a espécie de interesse foi identificada; machos e fêmeas foram quantificados e o desenvolvimento ovariano foi identificado segundo o critério de Sella. Dados metereológicos foram coletados visando correlacioná-los com a variacão sazonal da populacão de mosquitos. Foram coletados 8.298 mosquitos da espécie Culex quinquefasciatus. Desse total, 6.313 (76 por cento) eram machos e 1.985 (24 por cento) fêmeas. As fêmeas foram encontradas com o abdome vazio (90,1 por cento), com sangue (7,4 por cento) ou com óvulos maduros (2,5 por cento). As correlacões de número de mosquitos coletados versus temperatura mensal média e precipitacão mensal total não indicaram influência forte e positiva desses fatores na freqüência de mosquitos. A maior freqüência de machos pode ser explicada pela dispersão das fêmeas e pela permanência dos machos nos abrigos, representados pela vegetacão na margem do canal favorecendo o acúmulo de mosquitos.

Effect of food on immature development, consumption rate, and relative growth rate of Toxorhynchites splendens ( Diptera: Culicidae ), a predator of container breeding mosquitoes

Food utilization by the larvae of Toxorhynchites splendens (Wiedemann) was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston), and Culex quinquefasciatus (Say). Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id) and food availability were higher when offered early instars of prey (first and second instars) than late instars. Consumption rate (Cr) of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR) of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.