Abstract The genus Flavivirus comprises approximately 80 different viruses. Phylogenetic relationships among its members indicate a clear ecological separation between those viruses transmitted by mosquitoes, ticks, with no known vector, and insect-specific Flaviviruses. The diversity and phylogenetic relationships among insect-specific flaviviruses circulating in the central and northern regions of Argentina were studied by performing molecular detection and characterization of the NS5 protein gene in mosquitoes collected in Córdoba, Chaco and Tucumán provinces. Overall, 68 out of 1776 pools were positive. CxFV, KRV and CFAV circulate in the 3 studied provinces. Several mosquito species (Aedes aegypti, Culex bidens, Cx. dolosus, Cx. interfor, Cx. quinquefasciatus, Cx. saltanensis, Haemagogus spegazzini) were found infected. A wide circulation of CxFV was observed in the central-northern region of Argentina. CxFV strains detected in our study clustered with strains circulating in Santa Fe and Buenos Aires provinces (Argentina), and other countries such as Indonesia, Mexico, Uganda and Taiwan. The presence of these viruses in mosquitoes could play an important role from the public health perspective, because it has been shown that previous CxFV infection can increase or block the infection of the mosquito by other pathogenic flaviviruses. 8 ticks vector insectspecific insect specific Flaviviruses NS Córdoba Overall 6 177 positive Aedes aegypti bidens Cx dolosus interfor quinquefasciatus saltanensis spegazzini infected centralnorthern Argentina, , (Argentina) Indonesia Mexico Taiwan perspective 17 (Argentina 1

Resumen Se amplía el conocimiento sobre la distribución geográfica de Aedes patersoni Shanon y Del Ponte, Ae. scapularis (Rondani), Culex dolosus (Lynch Arribálzaga), Mansonia indubitans Dyar y Shannon, Psorophora cingulata (Fabricius), Toxorhynchites haemorrhoidalis separatus (Lynch Arribálzaga), Tx. purpureus (Theobald), Tx. theobaldi s. l. Dyar & Knab y Uranotaenia lowii Theobald en el Noroeste de Argentina. Asimismo, brindan las primeras localidades conocidas para Ma. indubitans en la provincia de Salta y para Ae. serratus (Theobald), Ma. titillans (Walker) y Ps. ciliata (Fabricius) en la provincia de Jujuy. Se discute sobre la presencia de Ae. fulvithorax (Lutz) en la provincia de Salta, de Ps. pallescens Edwards en la provincia de Jujuy, de Ur. pulcherrima Lynch Arribálzaga en Santiago del Estero y de Anopheles pictipennis (Philippi) en Argentina. Esta contribución actualiza la lista de mosquitos para las provincias del noroeste argentino, incrementando su número en Jujuy, La Rioja, Salta, Santiago del Estero y Tucumán a 68, 26, 102, 29 y 70 especies, respectivamente. Adicionalmente, se aporta información sobre el hábitat en el que se recolectaron y la importancia sanitaria de las especies mencionadas, así como una lista completa de las especies presentes en las provincias del noroeste argentino.

Abstract The knowledge about the geographical distribution of Aedes patersoni Shanon and Del Ponte, Ae. scapularis (Rondani), Culex dolosus (Lynch Arribálzaga), Mansonia indubitans Dyar and Shannon, Psorophora cingulata (Fabricius), Toxorhynchites haemorrhoidalis separatus (Lynch Arribálzaga), Tx. purpureus (Theobald), Tx. theobaldi s. l. Dyar & Knab and Uranotaenia lowii Theobald in the Northwest of Argentina is extended. Likewise, they provided the first known localities for Ma. indubitans in the province of Salta and for Ae. serratus (Theobald), Ma. titillans (Walker) and Ps. ciliata (Fabricius) in the province of Jujuy. The presence of Ae. fulvithorax (Lutz), Ps. pallescens Edwards in Jujuy, Ur. pulcherrima Lynch Arribálzaga in Santiago del Estero and Anopheles pictipennis (Philippi) in Argentina, is discussed. This contribution updates the list of mosquitoes for the northwestern provinces of Argentina, increasing their numbers of species in Jujuy, La Rioja, Salta, Santiago del Estero and Tucumán to 68, 26, 102, 29 and 70 species, respectively. Additionally, information on the habitat of immature stages and the sanitary importance of the species mentioned is provided, as well as a complete list of the species present in the northwestern provinces of Argentina.

Sand fly identification is complex because it depends on the expertise of the taxonomist. The females show subtle morphological differences and the occurrence of the species complexes are usual in this taxon. Therefore, a fragment of the cytochrome c oxidase subunit I (COI) gene is used for taxon barcoding to resolve this kind of problem. This study incorporates barcode sequences, for the first time, for Evandromyia cortelezzii and Migonemyia migonei from Argentina. The nucleotide sequence divergences were estimated to generate a neighbour-joining (NJ) tree. The automatic barcode gap discovery (ABGD) approach was employed to find the barcode gaps and the operational taxonomic unit (OTU) delimitation. Other species of the subtribe were included. The frequency histogram of divergences showed a barcoding gap. The ABGD analysis identified 14 operational taxonomic units (OTUs) from 13 morphological species. Sequences of Ev. cortelezzii and Mg. migonei formed well supported clusters and were diagnosed as primary species. These sequences are useful tools for molecular identification of the sand flies of the New World.

Aedes aegypti (Linnaeus) (Diptera: Culicidae) is a vector of etiological agents of yellow fever and dengue. An alternative to chemical control of this vector is the use of biological agents. Entomopathogenic nematodes are effective in pest control. The infectivity and life cycle of an Argentinean isolate of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) on Aedes aegypti larvae is registered for the first time under laboratory conditions. For each experimental unit, 30 second-instar larvae were exposed to 8 nematode doses (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1). The infective juveniles (IJs) used were multiplied on Galleria mellonella (Lepidoptera: Pyralidae). The infective continuity of IJs obtained from A. aegypti was tested applying the nematodes in a 100:1 dose on mosquito larvae. Larval mortality rates ranged from 0% to 84%. The larval mortality, the number of nematodes developed inside mosquito larvae and the number of new IJs increased with the increase of the nematodes dose. The results indicated that H. bacteriophora is able to infect A. aegypti larvae, and these nematodes can develop and produce new IJs, allowing the continuity of its life cycle.

Aedes aegypti (Linnaeus) (Diptera: Culicidae) es vector de los agentes etiológicos de la fiebre amarilla y del dengue. Una alternativa al control químico de este vector es el uso de agentes biológicos. Los nematodos entomopatógenos son efectivos en el control de plagas. La infectividad y el ciclo de vida de un aislado argentino de Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) en larvas de A. aegypti se registró por primera vez bajo condiciones de laboratorio. Para cada unidad experimental, 30 larvas de mosquito de segundo estadio fueron expuestas a 8 dosis del nematodo (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1). Los juveniles infectivos (JIs) utilizados fueron multiplicados sobre Galleria mellonella (Lepidoptera: Pyralidae). La continuidad infectiva de los JIs obtenidos de A. aegypti fue probada aplicándolos en una dosis de 100:1 sobre larvas del mosquito. Las tasas de mortalidad fueron de 0% a 84%. El número de nematodos desarrollados dentro de la larva de mosquito, la mortalidad larval y los nuevos JIs se incrementaron con el aumento de la dosis de nematodos. Los resultados indican que H. bacteriophora es capaz de infectar larvas de A. aegypti, se desarrolla y produce nuevos JIs, permitiendo la continuidad de su ciclo de vida.

The geographical distribution of Culex acharistus, C. bidens, C. chidesteri, C. dolosus, C. interfor, C. maxi, C. saltanensis and Ochlerotatus scapularis is extended, increasing the number of mosquito species in the provinces of Catamarca, from 14 to 20, and Santa Fe, from 57 to 59.

Se extiende la distribución geográfica de Culex acharistus, C. bidens, C. chidesteri, C. dolosus, C. interfor, C. maxi, C. saltanensis y Ochlerotatus scapularis, incrementando el número de especies de mosquitos citadas de las provincias de Catamarca, de 14 a 20, y de Santa Fe, de 57 a 59.

Entomopathogenic nematodes can be considered effective agents for biocontrol, resulting innocuous for humans. Larvaeof Culex apicinus Philippi were exposed to infective juveniles of Steinernema rarum (OLI strain) under laboratory conditions, testing six doses (1:1, 5:1, 10:1, 15:1, 100:1, 400:1). An increasing percentage of mosquito larvae mortality was recorded with an increased dose. The highest percentage of mosquito larvae mortality (75%) was obtained with the dose 400:1. This is the first report of parasitism of an isolated of S. rarum from Córdoba against larvae of C. apicinus, with promising results. Therefore, further studies must be carried out to determine if these nematodes would be effective as autochthonous agents for the control of Culex Linnaeus and other mosquitoes of sanitary interest in the country.

Los nemátodos entomopatógenos son considerados eficientes agentes de control de insectos plaga e inocuos para los humanos. Larvas de Culex apicinus Philippi fueron expuestas a seis dosis (1:1, 5:1, 10:1, 15:1, 100:1, 400:1) de juveniles infectivos de Steinernema rarum (aislado OLI). Se registró un incremento en la mortalidad de las larvas del mosquito con el aumento de la dosis del nematodo. El mayor porcentaje de mortalidad de larvas del mosquito (75%) se obtuvo con la dosis 400:1. Este es el primer reporte de parasitismo de un aislado de S. rarum de Córdoba, en larvas de C. apicinus con resultados promisorios. Por lo tanto, se debería profundizar su estudio para determinar si pueden resultar efectivos como agentes autóctonos para el control biológico de mosquitos Culex Linnaeus, y otros de interés sanitario en el país.

OBJECTIVE: To study the seasonal fluctuation of Aedes aegypti and to correlate its abundance with climate conditions. METHODS: Samples were weekly collected in ovitraps in the city of Resistencia, Chaco Province, Argentina, between October 2002 and November 2003. The number of eggs collected was correlated with temperature, relative humidity, evaporation and rainfalls recorded. Pearson's correlation test with the respective weekly climate data was used in single and multiple correlation analyses. RESULTS: The first record of eggs took place in the last week of October 2002 and continued irregularly up to the last week of June 2003, when no more eggs were seen until November 2003. The highest peak of abundance (70%) was observed in November-December 2002, which coincided with the season of high temperatures and rainfalls. A second less important peak was seen in April coinciding with autumn rainfalls. Significant correlations were found only for monthly accumulated rainfall (r=0.57; p<0.05). No ovipositions were recorded during the winter when temperature dropped below 16.5ºC. CONCLUSIONS: The results show a correlation between oviposition and rainfall, as the periods of high activity of Aedes aegypti were in the end of spring-beginning of summer, and beginning of fall. These are periods of major epidemiological risk if an infected person gets to Resistencia.

OBJETIVO: Estudiar la fluctuación estacional de Aedes aegypti y correlacionar su abundancia con factores ambientales. MÉTODOS: Las colectas fueron realizadas entre octubre de 2002 y noviembre de 2003, en la ciudad de Resistencia, província del Chaco, Argentina. Fueron hechos muestreos semanales empleando ovitrampas. El número de huevos colectados fue correlacionado con la temperatura, humedad relativa ambiente, evaporación y precipitaciones registradas en dicha localidad. Se utilizó el test de correlación de Pearson con los respectivos datos climáticos semanales, realizándose correlaciones simples y múltiples. RESULTADOS: La ocurrencia de huevos fue registrada de manera discontinua, desde la última semana de octubre de 2002, hasta la última de junio de 2003, a partir de la cual no fueron encontrados hasta noviembre de 2003. Se observó un pico de abundancia (70%) en noviembre y diciembre, que coincidió con el período de temperaturas altas y mayores precipitaciones. Otro pico, aunque de menor importancia, fue observado en abril y coincidió con las lluvias de otoño. Las correlaciones fueron significativas solamente para las precipitaciones acumuladas mensuales (r=0,57; P<0,05). No se registraron oviposturas en invierno cuando la temperatura media semanal fue inferior a 16,5ºC. CONCLUSIONES: Los resultados muestran correlación entre la oviposición y las precipitaciones, pues los períodos de mayor actividad de Aedes aegypti ocurrieron en el final de la primavera, comienzos del verano y en el inicio del otoño. Estos serían los períodos de mayor riesgo epidemiológico especialmente ante la aparición de personas infectadas.

OBJECTIVE: To study the seasonal fluctuation of Aedes aegypti and to correlate its abundance with climate conditions. METHODS: Samples were weekly collected in ovitraps in the city of Resistencia, Chaco Province, Argentina, between October 2002 and November 2003. The number of eggs collected was correlated with temperature, relative humidity, evaporation and rainfalls recorded. Pearson's correlation test with the respective weekly climate data was used in single and multiple correlation analyses. RESULTS: The first record of eggs took place in the last week of October 2002 and continued irregularly up to the last week of June 2003, when no more eggs were seen until November 2003. The highest peak of abundance (70%) was observed in November-December 2002, which coincided with the season of high temperatures and rainfalls. A second less important peak was seen in April coinciding with autumn rainfalls. Significant correlations were found only for monthly accumulated rainfall (r=0.57; p<0.05). No ovipositions were recorded during the winter when temperature dropped below 16.5ºC. CONCLUSIONS: The results show a correlation between oviposition and rainfall, as the periods of high activity of Aedes aegypti were in the end of spring-beginning of summer, and beginning of fall. These are periods of major epidemiological risk if an infected person gets to Resistencia.

OBJETIVO: Estudiar la fluctuación estacional de Aedes aegypti y correlacionar su abundancia con factores ambientales. MÉTODOS: Las colectas fueron realizadas entre octubre de 2002 y noviembre de 2003, en la ciudad de Resistencia, província del Chaco, Argentina. Fueron hechos muestreos semanales empleando ovitrampas. El número de huevos colectados fue correlacionado con la temperatura, humedad relativa ambiente, evaporación y precipitaciones registradas en dicha localidad. Se utilizó el test de correlación de Pearson con los respectivos datos climáticos semanales, realizándose correlaciones simples y múltiples. RESULTADOS: La ocurrencia de huevos fue registrada de manera discontinua, desde la última semana de octubre de 2002, hasta la última de junio de 2003, a partir de la cual no fueron encontrados hasta noviembre de 2003. Se observó un pico de abundancia (70%) en noviembre y diciembre, que coincidió con el período de temperaturas altas y mayores precipitaciones. Otro pico, aunque de menor importancia, fue observado en abril y coincidió con las lluvias de otoño. Las correlaciones fueron significativas solamente para las precipitaciones acumuladas mensuales (r=0,57; P<0,05). No se registraron oviposturas en invierno cuando la temperatura media semanal fue inferior a 16,5ºC. CONCLUSIONES: Los resultados muestran correlación entre la oviposición y las precipitaciones, pues los períodos de mayor actividad de Aedes aegypti ocurrieron en el final de la primavera, comienzos del verano y en el inicio del otoño. Estos serían los períodos de mayor riesgo epidemiológico especialmente ante la aparición de personas infectadas.

The list of twenty-two species of Culicidae from the southern coast of Mar Chiquita Lake is extended to twenty-eight. Aedeomyia squamipennis (Lynch Arribalzaga) , Culex acharistus Root, Culex chidesteri Dyar, Haemagogus spegazzinii Brèthes , Mansonia titillans (Walker) and Psorophora holmbergi Lynch Arribalzaga are listed for the first time for the region. The available information on sanitary importance of the culicids of the area is summarized.

Se amplía la lista de veintidos especies de Culicidae citadas para el arco sur de la Laguna de Mar Chiquita a veintiocho. Aedeomyia squamipennis (Lynch Arribalzaga) , Culex acharistus Root, Culex chidesteri Dyar, Haemagogus spegazzinii Brèthes, Mansonia titillans (Walker) y Psorophora holmbergi Lynch Arribalzaga se citan por primera vez para la región. Se sintetizan los antecedentes relacionados con la importancia sanitaria de los culícidos de la zona.

Allele frequencies at seven polymorphic loci controlling the synthesis of enzymes were analyzed in six populations of Culex pipiens L. and Cx. quinquefasciatus Say. Sampling sites were situated along a north-south line of about 2,000 km in Argentina. The predominant alleles at Mdh, Idh, Gpdh and Gpi loci presented similar frequencies in all the samples. Frequencies at the Pgm locus were similar for populations pairs sharing the same geographic area. The loci Cat and Hk-1 presented significant geographic variation. The latter showed a marked latitudinal cline, with a frequency for allele b ranging from 0.99 in the northernmost point to 0.04 in the southernmost one, a pattern that may be explained by natural selection (FST = 0.46; p < 0.0001) on heat sensitive alleles. The average value of FST (0.088) and Nm (61.12) indicated a high gene flow between adjacent populations. A high correlation was found between genetic and geographic distance (r = 0.83; p < 0.001). The highest genetic identity (IN = 0.988) corresponded to the geographically closest samples from the central area. In one of these localities Cx. quinquefasciatus was predominant and hybrid individuals were detected, while in the other, almost all the specimens were identified as Cx. pipiens. To verify the fertility between Cx. pipiens and Cx. quinquefasciatus from the northern- and southernmost populations, experimental crosses were performed. Viable egg rafts were obtained from both reciprocal crosses. Hatching ranged from 76.5 to 100%. The hybrid progenies were fertile through two subsequent generations

Adult cohorts and immature stages were kept under field conditions during the autumn and winter of three consecutive years. Survival, oviposition and development time from egg to adult were considered. The adult cohorts were studied under three experimental conditions: unfed cohorts, cohorts fed with sugar solution ansd cohorts fed with both sugar solution and blood (chicken). Female longevity showed significant differences among the three treatments. Females of unfed cohorts lived up to three weeks; females fed with sugar solution survived until six weeks, while those fed both with sugar and blood lived at most fourteen weeks; after the blood intake eggs were laid. In the immature stages, the highest relative mortality rates occurred during the egg and larval stages. Total pre-adult mortality varied between 59.09 and 89.71%. The developmental duration from egg to adult was between 43-62 days; there were no differences among results obtained for the three years.

Culex (Culex) maxi Dyar is described in the adult, pupal and larval stages, and the male genitalia and parts of the fourth-instar larva are illustrated. The larva is described for the first time. The paper includes a summary of available information on the taxonomy, bionomics and distribution of the species. The taxonomy and identification of the species are reviewed in light of current knowledge of the subgenus Culex in the New World.

In order to classify mosquito immature stage habitats, samples were taken in 42 localities of Córdoba Province, Argentina, representing the phytogeographic regions of Chaco, Espinal and Pampa. Immature stage habitats were described and classified according to the following criteria: natural or artificial; size; location related to light and neighboring houses; vegetation; water: permanence, movement, turbidity and pH. Four groups of species were associated based on the habitat similarity by means of cluster analysis: Aedes albifasciatus, Culex saltanensis, Cx. mollis, Cx. brethesi, Psorophora ciliata, Anopheles albitarsis, and Uranotaenia lowii (Group A); Cx. acharistus, Cx. quinquefasciatus, Cx. bidens, Cx. dolosus, Cx. maxi and Cx. apicinus (Group B); Cx. coronator, Cx. chidesteri, Mansonia titillans and Ps. ferox (Group C); Ae. fluviatilis and Ae. milleri (Group D). The principal component analysis (ordination method) pointed out that the different types of habitats, their nature (natural or artificial), plant species, water movement and depth are the main characters explaining the observed variation among the mosquito species. The distribution of mosquito species by phytogeographic region did not affect the species groups, since species belonging to different groups were collected in the same region.

To better undesrtand the distribution of Culex pipiens and Cx. quinquefasciatus in Argentina, samples were collected from six localities situated in a North-South line from Castelli (Chaco Province) to Puerto Madryn (Chubut Province). Identification was based on the morphology of male genitalia. Only Cx. quinquefasciatus was found in Castelli and Esperanza, while in Rosario, 95.3% belonged to this species and 4.7% represented hybrid forms. Southern samples included only Cx. pipiens. With the purpose of verfying if Cx. pipiens and Cx. quinquefasciatus hybridize, different crosses between the two species were perfomed. All crosses produced viable egg rafts. Hatching ranged from 70 to 100%, except in one cross, female Cx. pipiens x male Cx. quinquefasciatus, where a high incompatibility was observed (11.1%hatch). The F1 hybrids obtained all crosses were fertile. The finding of hybrid forms in nature can be interpreted as evidence for subspecific status of Cx. pipiens and Cx. quinquefasciatus in Argentina.

In order to study the host preference of female mosquitoes, samples were taken fortnightly in Cordoba and Cosquin (Argentina), during October-April of two consecutive years. Four different vertebrates were used in baited-can traps: frogs, chickens, rabbits and turtles. The genus Culex acounted for 92.9% of the specimens collected, Aedes for 7.0% and Psorophora ciliata 0.02%. The highest proportion of females were collected in chicken traps (68.7%), followed by rabbit traps (29.9%), turtles (0.8%) and frogs (0.5%), thus the majority of the mosquitoes were collected in traps with homeotermous hosts. Only Culex dolosus fed on all the hosts. Culex acharistus, Cx. chidesteri and Cx. quinquefasciatus fed on chickens, rabbits and turtles. Aedes albifasciatus, Ae. scapularis, Cx. bidens and Cx. coronator fed on both homeotermous hosts. Culex apicinus, Cx. maxi, Cx. saltanensis and Cx. spinosus fed only on chickens and Ps. ciliata only on rabbits.

Con el propósito de estudiar la preferencia de hospedadores vertebrados por mosquitos hembras, durante 2 períodos octubre-abril (primavera-verano), se realizaron muestreos cada 15 días en Córdoba y Cosquín (Argentina). Se utilizaron trampas de latón con cebo animal: anfibios (sapos), aves (pollos), mamíferos (conejos) y reptiles (tortugas). El 92,9% de los especímenes recolectados pertenecen al género Culex, mientras que un 7,0% corresponde a Aedes y el 0,02% restante a Psorophora ciliata, única especie que se capturó de ese género. En trampas con pollo se recolectó el mayor número de hembras (68,7%), siguiendo en orden las trampas con conejos (29,9%), con tortugas (0,8%) y con sapos (0,5%), por lo tanto, la mayoría de los mosquitos entraron en las trampas con hospedadores homeotermos. Culex dolosus se alimentó sobre todos los cebos, mientras que Cx. acharistus, Cx. chidesteri y Cx. quinquefasciatus se alimentaron sobre pollos, conejos y tortugas; Ae. albifasciatus, Ae. scapularis, Cx. bidens y Cx. coronator lo hicieron sobre ambos hospedadores homeotermos; Cx. apicinus, Cx. maxi, Cx. saltanensis y Cx. spinosus se alimentaron solamente sobre pollos y Ps. ciliata sobre conejos.

Com o propósito de estudar a preferência de mosquitos fêmeas por hospedeiros vertebrados, realizaram-se amostragens quinzenais nas cidades de Córdoba e Cosquín (Argentina), durante o período de outubro a abril (primavera-verão), por dois anos consecutivos. Utilizaram-se armadilhas com iscas animais: anfíbios, aves, mamíferos e répteis. Dos espécimes coletados, 92,9% pertenciam ao gênero Culex, 7,0% a Aedes e 0,02% a Psorophora ciliata, única espécie coletada desse gênero. A maior proporçãoo de fêmeas (68,7%) foi capturada em armadilhas iscadas com galinhas, seguindo-se em ordem as armadilhas com coelhos (29,9%), com tartarugas (0,8%) e com anfíbios (0,05%). Assim, a maioria dos mosquitos foi coletada em armadilhas com hospedeiros homeotermos. Culex dolosus alimentou-se em todas as iscas, enquanto que Cx. acharistus, Cx. chidesteri e Cx. quinquefasciatus em galinhas, coelhos e tartarugas; Ae. albifasciatus, Ae. scapularis, Cx. bidens e Cx. coronator fizeram-no em ambos hospedeiros homeotermos; Cx. apicinus, Cx. maxi, Cx. saltanensis e Cx. spinosus alimentaram-se apenas em galinhas e Ps. ciliata em coelhos.