Evaluation of <i>Mesocyclops annulatus</i> (Copepoda: Cyclopoidea) as a control agent of <i>Aedes aegypti</i> (Diptera: Culicidae) in Argentina

We evaluated the potential of Mesocyclops annulatus as a control agent of Aedes aegypti in La Plata city (Argentina). Mosquito larval survivorship due to predation by these copepods was estimated at weekly intervals during the oviposition period of A. aegypti. Mean weekly A. aegypti larval survivorship in cylindrical plastic containers (12 cm height and 11 cm diameter) with copepods was significantly lower than in control containers. Furthermore, weekly larval survival was negatively correlated with M. annulatus adult density, and approximately 23 adult copepods/container would be a threshold density over which the weekly mosquito larval survivorship approached zero. The copepods were able to persist in all containers during approximately 100 days (in three of them until the end of the experiment: 155 days) without the resource represented by A. aegypti larvae. The predation and persistence observed suggest that M. annulatus is a potential control agent to be considered in biological control programs.Facultad de Ciencias Naturales y Muse

Laboratory evaluation of Mesocyclops annulatus (Wierzejski, 1892) (Copepoda: Cyclopidea) as a predator of container-breeding mosquitoes in Argentina

In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae. A single adult female of M. annulatus caused 51.6% and 52.3% mortality of 50 first instar larvae of Ae. aegypti and Cx. pipiens respectively, in a 72 h test period. When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae. aegypti and Cx. pipiens respectively. When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of M. annulatus, mortality rates were 75.5% for Ae. aegypti larvae and 23.5% for Cx. pipiens larvae in a three day test period. Different density of adult females of M. annulatus ranged from 5 to 25 females produced mortality rates of Ae. aegypti first instar larvae from 50% to 100% respectively. When a single adult female of M. annulatus was exposed to an increasing number of first-instar Ae. aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae. The average larvae killed per 24 h period by a single copepod were 29.Centro de Estudios Parasitológicos y de Vectore

Phylogenetics Based on Partial ORF2 of Triatoma Virus in Triatomines Collected over a Decade from Domiciliary Habitats

The only virus sequenced and studied in triatomines is the Triatoma virus, from the Dicistroviridae family, which causes delayed development, reduced oviposition, and premature death of infected insects. With the goal of expanding the sequences already obtained in previous years and verifying if any changes occurred in their genomic sequences, 68 samples of triatomines from several provinces of Argentina were analyzed. Sixteen positive samples were obtained by Reverse Transcription (RT)-polymerase chain reaction using the VP3-VP1 subregion of open reading frame-2 as a diagnostic method; after sequencing, 11 samples were obtained from Triatoma infestans. These new sequences showed no significant differences in the analyzed regions, which were not grouped by species or habitat or geographical distribution. There were no differences when compared with the sequences found during 2002-2012, all obtained from the wild.We conclude that despite being an RNA virus, the different sequences show high homology.Centro de Estudios Parasitológicos y de VectoresFacultad de Ciencias Veterinaria

First record of <i>Aedes aegypti</i> (L.) (Diptera: Culicidae) infected by the parasite <i>Ascogregarina culicis</i> (Ross) (Apicomplexa: Lecudinidae) in Argentina

In a survey for parasites and pathogens of Aedes aegypti conducted in La Plata, Argentina, an aseptate gregarine was found parasitizing larvae, pupae and adults of this mosquito species. This gregarine species was identified as Ascogregarina culicis based on the morphology and size of gamonts, gametocysts and oocysts. It is the first record of gregarine infections in culicids from ArgentinaCentro de Estudios Parasitológicos y de VectoresConsejo Nacional de Investigaciones Científicas y TécnicasComisión de Investigaciones Científicas de la provincia de Buenos Aire

First record of <i>Aedes aegypti</i> (L.) (Diptera: Culicidae) infected by the parasite <i>Ascogregarina culicis</i> (Ross) (Apicomplexa: Lecudinidae) in Argentina

In a survey for parasites and pathogens of Aedes aegypti conducted in La Plata, Argentina, an aseptate gregarine was found parasitizing larvae, pupae and adults of this mosquito species. This gregarine species was identified as Ascogregarina culicis based on the morphology and size of gamonts, gametocysts and oocysts. It is the first record of gregarine infections in culicids from ArgentinaCentro de Estudios Parasitológicos y de VectoresConsejo Nacional de Investigaciones Científicas y TécnicasComisión de Investigaciones Científicas de la provincia de Buenos Aire

First record of <i>Aedes aegypti</i> (L.) (Diptera: Culicidae) infected by the parasite <i>Ascogregarina culicis</i> (Ross) (Apicomplexa: Lecudinidae) in Argentina

In a survey for parasites and pathogens of Aedes aegypti conducted in La Plata, Argentina, an aseptate gregarine was found parasitizing larvae, pupae and adults of this mosquito species. This gregarine species was identified as Ascogregarina culicis based on the morphology and size of gamonts, gametocysts and oocysts. It is the first record of gregarine infections in culicids from ArgentinaCentro de Estudios Parasitológicos y de VectoresConsejo Nacional de Investigaciones Científicas y TécnicasComisión de Investigaciones Científicas de la provincia de Buenos Aire

Orden Hemiptera, Suborden Heteroptera

El nombre Hemiptera, que literalmente significa mitad/alas, deriva de la característica de las alas, donde el par anterior es de mayor consistencia que el par posterior, el cual es completamente membranoso. Las alas anteriores pueden ser uniformes como las del suborden Homoptera, o con una porción basal coriácea, y una porción distal membranosa, los hemiélitros de los miembros del suborden Heteroptera. El orden Hemiptera comprende cerca de 90.000 especies en todo el mundo. Actualmente existen cuatro subórdenes: el suborden Coleorrhyncha (con una familia), el suborden Heteroptera (75 familias) y el antiguo suborden Homoptera que actualmente comprende dos subórdenes: Auchenorrhyncha (con las piezas bucales que se observan surgir del margen posterior de la cabeza, 28 familias) y los Sternorrhyncha (con las piezas bucales que parecen surgir entre las coxas I o están ausentes, 41 familias). Las piezas bucales del orden están adaptadas a la extracción de líquidos con una misma estructura básica, el gran y usualmente tubular labio a modo de estuche que incorpora el labro, y a las mandíbulas y maxilas altamente modificadas a modo de estiletes. No presentan palpos labiales ni maxilares. Todo el conjunto del labio más los estiletes es conocido como rostro o proboscis. Los “Homoptera” se alimentan exclusivamente de jugos de plantas y los Heteroptera incluyen especies fitófagas, predadoras y hematófagas. Los Hemiptera no hematófagos que ocasionalmente pueden picar humanos son tratados en el Capítulo 16.Facultad de Ciencias Naturales y Muse

Evaluation of <i>Mesocyclops annulatus</i> (Copepoda: Cyclopoidea) as a control agent of <i>Aedes aegypti</i> (Diptera: Culicidae) in Argentina

We evaluated the potential of Mesocyclops annulatus as a control agent of Aedes aegypti in La Plata city (Argentina). Mosquito larval survivorship due to predation by these copepods was estimated at weekly intervals during the oviposition period of A. aegypti. Mean weekly A. aegypti larval survivorship in cylindrical plastic containers (12 cm height and 11 cm diameter) with copepods was significantly lower than in control containers. Furthermore, weekly larval survival was negatively correlated with M. annulatus adult density, and approximately 23 adult copepods/container would be a threshold density over which the weekly mosquito larval survivorship approached zero. The copepods were able to persist in all containers during approximately 100 days (in three of them until the end of the experiment: 155 days) without the resource represented by A. aegypti larvae. The predation and persistence observed suggest that M. annulatus is a potential control agent to be considered in biological control programs.Facultad de Ciencias Naturales y Muse

Laboratory evaluation of Mesocyclops annulatus (Wierzejski, 1892) (Copepoda: Cyclopidea) as a predator of container-breeding mosquitoes in Argentina

In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae. A single adult female of M. annulatus caused 51.6% and 52.3% mortality of 50 first instar larvae of Ae. aegypti and Cx. pipiens respectively, in a 72 h test period. When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae. aegypti and Cx. pipiens respectively. When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of M. annulatus, mortality rates were 75.5% for Ae. aegypti larvae and 23.5% for Cx. pipiens larvae in a three day test period. Different density of adult females of M. annulatus ranged from 5 to 25 females produced mortality rates of Ae. aegypti first instar larvae from 50% to 100% respectively. When a single adult female of M. annulatus was exposed to an increasing number of first-instar Ae. aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae. The average larvae killed per 24 h period by a single copepod were 29.Centro de Estudios Parasitológicos y de Vectore

Molecular Techniques for Dicistrovirus Detection without RNA Extraction or Purification

Dicistroviridae is a new family of small, nonenveloped, and +ssRNA viruses pathogenic to both beneficial arthropods and insect pests as well. Triatoma virus (TrV), a dicistrovirus, is a pathogen of Triatoma infestans (Hemiptera: Reduviidae), one of the main vectors of Chagas disease. In this work, we report a single-step method to identify TrV, a dicistrovirus, isolated from fecal samples of triatomines. The identification method proved to be quite sensitive, even without the extraction and purification of RNA virus.Centro de Estudios Parasitológicos y de Vectore