First record of <i>Vitalius longisternalis</i> Bertani, 2001 (Araneae, Theraphosidae) in Argentina and notes on its natural history in Misiones province

This is the first record for the tarantula Vitalius longisternalis Bertani, 2001 in Parana and Araucaria Forests, Misiones province, northeastern Argentina. Specimens were found at Iguazú National Park and Urugua-í Wildlife Reserve. Data on its natural history is provided.Centro de Estudios Parasitológicos y de Vectore

First record of <i>Vitalius longisternalis</i> Bertani, 2001 (Araneae, Theraphosidae) in Argentina and notes on its natural history in Misiones province

This is the first record for the tarantula Vitalius longisternalis Bertani, 2001 in Parana and Araucaria Forests, Misiones province, northeastern Argentina. Specimens were found at Iguazú National Park and Urugua-í Wildlife Reserve. Data on its natural history is provided.Centro de Estudios Parasitológicos y de Vectore

¿Puedes encontrarme? Respuesta sexual en una tarántula de Argentina (Araneae, Therphosidae)

We described and analyzed the female sexual response in the tarantula Grammostola vachoni Schiapelli and Gerschman 1961 under three series of 10 experiments each with different situations for the male-female encounters: male free in terrarium but with no access to female; male confined into a glass cup at 30 cm of female burrow and; male confined into a glass cup over a heavy stone closing the female burrow. We observed leg palpal tapping and body movements of female in response to male courtship. Leg and palpal tapping could indicate a female receptive condition and her attractiveness. Also, this behavior may serve to orient male towards her location. These females responded with leg and palpal tapping only to males which present long courtships together with active searching (walking) for female location. The female body movements, originated by legs III, are interpreted here as a rejection considering that male stopped courting and tried to escape.Se describe y analiza la respuesta sexual en hembras de la tarántula Grammostola vachoni en tres series de 10 experimentos cada uno bajo diferentes situaciones de encuentros entre machos y hembras: machos libres en el terrario pero sin acceso a la hembra; machos confinados dentro de un recipiente de vidrio a 30 cm de la cueva de la hembra y machos confinados en el recipiente de vidrio sobre una piedra cerrando la entrada de la cueva de la hembra. Se observaron golpes con patas y palpos y movimientos corporales de las hembras en respuesta al cortejo de los machos. Los golpes con patas y palpos podrían indicar la receptividad de las hembras y su atracción. También, este comportamiento podría orientar al macho hacia su posición. Estas hembras contestaron con golpes de patas y palpos sólo a los machos que realizaron cortejos largos junto a una búsqueda activa de la cueva de la hembra. Los movimientos corporales de la hembra, originados con patas III, se interpretan como un rechazo considerando que el macho dejó de cortejar e intentó escapar.Centro de Estudios Parasitológicos y de Vectore

¿Puedes encontrarme? Respuesta sexual en una tarántula de Argentina (Araneae, Therphosidae)

We described and analyzed the female sexual response in the tarantula Grammostola vachoni Schiapelli and Gerschman 1961 under three series of 10 experiments each with different situations for the male-female encounters: male free in terrarium but with no access to female; male confined into a glass cup at 30 cm of female burrow and; male confined into a glass cup over a heavy stone closing the female burrow. We observed leg palpal tapping and body movements of female in response to male courtship. Leg and palpal tapping could indicate a female receptive condition and her attractiveness. Also, this behavior may serve to orient male towards her location. These females responded with leg and palpal tapping only to males which present long courtships together with active searching (walking) for female location. The female body movements, originated by legs III, are interpreted here as a rejection considering that male stopped courting and tried to escape.Se describe y analiza la respuesta sexual en hembras de la tarántula Grammostola vachoni en tres series de 10 experimentos cada uno bajo diferentes situaciones de encuentros entre machos y hembras: machos libres en el terrario pero sin acceso a la hembra; machos confinados dentro de un recipiente de vidrio a 30 cm de la cueva de la hembra y machos confinados en el recipiente de vidrio sobre una piedra cerrando la entrada de la cueva de la hembra. Se observaron golpes con patas y palpos y movimientos corporales de las hembras en respuesta al cortejo de los machos. Los golpes con patas y palpos podrían indicar la receptividad de las hembras y su atracción. También, este comportamiento podría orientar al macho hacia su posición. Estas hembras contestaron con golpes de patas y palpos sólo a los machos que realizaron cortejos largos junto a una búsqueda activa de la cueva de la hembra. Los movimientos corporales de la hembra, originados con patas III, se interpretan como un rechazo considerando que el macho dejó de cortejar e intentó escapar.Centro de Estudios Parasitológicos y de Vectore

First record of Vitalius longisternalis Bertani, 2001 (Araneae, Theraphosidae) in Argentina and notes on its natural history in Misiones province

This is the first record for the tarantula Vitalius longisternalis Bertani, 2001 in Parana and Araucaria Forests, Misiones province, northeastern Argentina. Specimens were found at Iguazú National Park and Urugua-í Wildlife Reserve. Data on its natural history is provided.Tarantula, Parana, Araucaria Forest, distribution extensio

On the ecology of the cursorial spider Odo bruchi (Araneae: Zoridae) in a grassland natural reserve from central Argentina

The “Ernesto Tornquist” Provincial Park (ETPP) is located inside the Ventania system (Argentina) and was created to protect one of the last relicts of pampean grasslands. Even though many studies have looked at the vertebrate faunal diversity, biology, and conservation in this Park, few studies have been dedicated to arthropods. Among these, spiders have been used as ecological indicators to evaluate nature conservation status, nevertheless, basic information on their distribution and ecology is necessary for their use as indicator taxa in this region. Thus the goal of this study was to present the phenology and demography of the spider Odo bruchi, a cursorial spider present in the ETPP. For this, spiders were sampled bimonthly using pitfall traps between September 2009-2010 (first year), and March 2011-2012 (second year). A total of 10 traps were placed every 10m along a transect of 100m parallel to the longest axis of a grassland slope with native vegetation. Traps were filled with 1 500mL of ethylene glycol, that were examined and refilled every 60 day period. We collected a total of 799 specimens in two years. Juveniles were the most abundant reaching 47.8% of the total, while males corresponded to 27.8% and females 24.4%. We found significant differences in the mean abundance of O. bruchi: the abundance during spring-summer (Nov-Dec-Jan-Feb) was significantly higher than the other periods of the two years period. Moreover, we found an even abundance distribution throughout the year in the entire study. This work represents one of the first contributions to the ecology of this spider family in the area. Also, our results comprise relevant information to encourage future studies on this spider species as a bio-indicator of the conservation status of pampean grasslands.Universidad Nacional del SurConsejo Nacional de Investigaciones Científicas y TécnicasCentro de Estudios Parasitológicos y de Vectore

First record of <i>Vitalius longisternalis</i> Bertani, 2001 (Araneae, Theraphosidae) in Argentina and notes on its natural history in Misiones province

This is the first record for the tarantula Vitalius longisternalis Bertani, 2001 in Parana and Araucaria Forests, Misiones province, northeastern Argentina. Specimens were found at Iguazú National Park and Urugua-í Wildlife Reserve. Data on its natural history is provided.Centro de Estudios Parasitológicos y de Vectore

Dieta de la viuda negra, <i>Latrodectus mirabilis</i> (Theridiidae) en dos cultivos de cereales del centro de Argentina

The spider Latrodectus mirabilis (Holmberg, 1876) is commonly found in cereals crops of central Argentina. We studied its diet composition at the field and capture rate on leaf-cutting ants based on laboratory experiments. This study comprises the first approach that documents the diet of L. mirabilis in wheat and oat fields of central Argentina. We identified 1,004 prey items collected from its webs during the last phenological stages of both cereal crops. The prey composition was variable but the spiders prey mainly on ants (Formicidae, Hymenoptera), who represented more than 86% of the total. Meanwhile, in the capture rate experiences we registered a high proportion of ants captured by spiders at the beginning of experiences, capturing the half of the ants from total in the first four hours. Summarizing, we reported a polyphagous diet of this spider species in wheat and oat fields. Ants were the most important prey item of this spider, as found in other Latrodectus spiders around the world.La araña Latrodectus mirabilis (Holmberg, 1876) se encuentra comúnmente en cultivos de cereales del centro de Argentina. Se estudió la composición de la dieta a campo y la tasa de captura sobre hormigas cortadoras negras a laboratorio. Este estudio documenta el primer registro de la dieta de L. mirabilis en cultivos de trigo y avena del centro de Argentina. Se identificaron 1004 ítem presa colectados de las telas de L. mirabilis en las últimas etapas fenológicas de ambos cultivos. La composición de presas fue variable, pero las arañas se alimentaron principalmente de hormigas (Formicidae, Hymenoptera), las cuales representaban más del 86% del total de las presas capturadas. A su vez, en las experiencias de tasa de captura, registramos una alta tasa de captura de hormigas al inicio de las mismas, capturando la mitad de las hormigas en las primeras cuatro horas. En resumen, reportamos una dieta polífaga en esta especie de araña en los cultivos de trigo y avena. El ítem presa más importante fueron las hormigas, resultados similares a los encontrados en otras especies del género Latrodectus.Centro de Estudios Parasitológicos y de Vectore

Dieta de la viuda negra, <i>Latrodectus mirabilis</i> (Theridiidae) en dos cultivos de cereales del centro de Argentina

The spider Latrodectus mirabilis (Holmberg, 1876) is commonly found in cereals crops of central Argentina. We studied its diet composition at the field and capture rate on leaf-cutting ants based on laboratory experiments. This study comprises the first approach that documents the diet of L. mirabilis in wheat and oat fields of central Argentina. We identified 1,004 prey items collected from its webs during the last phenological stages of both cereal crops. The prey composition was variable but the spiders prey mainly on ants (Formicidae, Hymenoptera), who represented more than 86% of the total. Meanwhile, in the capture rate experiences we registered a high proportion of ants captured by spiders at the beginning of experiences, capturing the half of the ants from total in the first four hours. Summarizing, we reported a polyphagous diet of this spider species in wheat and oat fields. Ants were the most important prey item of this spider, as found in other Latrodectus spiders around the world.La araña Latrodectus mirabilis (Holmberg, 1876) se encuentra comúnmente en cultivos de cereales del centro de Argentina. Se estudió la composición de la dieta a campo y la tasa de captura sobre hormigas cortadoras negras a laboratorio. Este estudio documenta el primer registro de la dieta de L. mirabilis en cultivos de trigo y avena del centro de Argentina. Se identificaron 1004 ítem presa colectados de las telas de L. mirabilis en las últimas etapas fenológicas de ambos cultivos. La composición de presas fue variable, pero las arañas se alimentaron principalmente de hormigas (Formicidae, Hymenoptera), las cuales representaban más del 86% del total de las presas capturadas. A su vez, en las experiencias de tasa de captura, registramos una alta tasa de captura de hormigas al inicio de las mismas, capturando la mitad de las hormigas en las primeras cuatro horas. En resumen, reportamos una dieta polífaga en esta especie de araña en los cultivos de trigo y avena. El ítem presa más importante fueron las hormigas, resultados similares a los encontrados en otras especies del género Latrodectus.Centro de Estudios Parasitológicos y de Vectore

Datos preliminares acerca de interacciones entre dos avispas pompílidas y tarántulas en el sur de Buenos Aires, Argentina

En el presente estudio se presentan datos preliminares sobre la depredación de dos especies de avispas (Pompilidae: Pepsis aciculata y Notocyphus sp.) sobre dos especies de tarántulas (Teraphosidae: Grammostola vachoni y Plesiopelma longisternale) en el sur de la provincia de Buenos Aires. En un experimento de laboratorio se observó el comportamiento de ataque de una hembra de P. aciculata a cuatro hembras de G. vachoni. En dos casos la avispa ingresó a la cueva de las hembras y atacó a la araña, aunque solamente en un caso logró la inmovilización total de la araña y la oviposición. En el caso de Notocyphus sp., una hembra adulta de P. longisternale se halló en el campo con una larva en el dorso de su abdomen. La larva consumió a la araña en 18 días y el adulto eclosionó cinco meses después. Los resultados contribuyen al conocimiento de las interacciones entre avispas pompílidas y tarántulas en Argentina.In this study we report preliminary information about pompilid wasp predation (Pepsis aciculata and Notocyphus sp.) of two tarantulas (Grammostola vachoni and Plesiopelma longisternale) in the south of Buenos Aires province. In a laboratory experiment we observed the attack behavior of a P. aciculata female on four females of G. vachoni. In two cases, wasps entered into the females’ burrows and attacked, but only one case resulted in an effective immobilization of the spider and egg deposition. In the case of Notocyphus sp., an adult female of P. longisternale was found in the field with a larva on her abdomen. The larva ate the whole spider 18 days later and the adult emerged five months later. These results contribute to the knowledge of interactions between pompilid wasps and tarantulas in Argentina.Centro de Estudios Parasitológicos y de Vectore