Mygalomorphae spider community of the Natural Reserve Sierra del Tigre, Tandilia, Buenos Aires, Argentina

We documented the specific richness, abundance and activity of the Mygalomorph spider community in the Natural Reserve Sierra del Tigre, Buenos Aires, Argentina. This hilly ecosystem is home for many endemic species and rich in native fauna and flora. Spider abundance was sampled monthly from May 2011 - May 2012 by hand capture and pitfall traps. The species recorded in the study area were Actinopus sp. 1 (Actinopodidae), Grammostola vachoni Schiapelli y Gerschman, 1960; Plesiopelma longisternale Schiapelli y Gerschman, 1942 and Catumiri argentinense (Mello-Leitão, 1941) (Theraphosidae). Grammostola vachoni was the dominant species in hand capture and Actinopus sp. 1 in pitfall traps. The seasonal variation, diversity, and abundance of the mygalomorph community are analyzed and discussed here. The Mygalomorphae of the Tandilia system comprises an important group of sedentary and cryptozoic spiders that seem to be dependent on habitat type and environmental factors.En el presente trabajo se analizó la riqueza específica, abundancia y actividad de la comunidad de arañas Mygalomorphae en la Reserva Natural Sierra del Tigre, Buenos Aires, Argentina. Este ecosistema serrano alberga numerosas especies endémicas y es rico en fauna y flora nativa. La abundancia de arañas se muestreó mensualmente desde mayo de 2011 a mayo de 2012, mediante recolección manual y trampas de caída. Las especies registradas en el área de estudio fueron Actinopus sp. 1 (Actinopodidae), Grammostola vachoni Schiapelli y Gerschman, 1960; Plesiopelma longisternale Schiapelli y Gerschman, 1942 y Catumiri argentinense (Mello-Leitão, 1941) (Theraphosidae). Grammostola vachoni resultó la especie dominante en la recolección manual y Actinopus sp. 1 en trampas de caída. Se discuten y analizan la variación estacional, diversidad y abundancia de la comunidad de migalomorfas. Las Mygalomorphae del sistema de Tandilia comprenden un grupo importante de arañas sedentarias y criptozoicas que parecen depender del tipo de ambiente y factores ambientales.Centro de Estudios Parasitológicos y de Vectore

Mygalomorphae spider community of the Natural Reserve Sierra del Tigre, Tandilia, Buenos Aires, Argentina

We documented the specific richness, abundance and activity of the Mygalomorph spider community in the Natural Reserve Sierra del Tigre, Buenos Aires, Argentina. This hilly ecosystem is home for many endemic species and rich in native fauna and flora. Spider abundance was sampled monthly from May 2011 - May 2012 by hand capture and pitfall traps. The species recorded in the study area were Actinopus sp. 1 (Actinopodidae), Grammostola vachoni Schiapelli y Gerschman, 1960; Plesiopelma longisternale Schiapelli y Gerschman, 1942 and Catumiri argentinense (Mello-Leitão, 1941) (Theraphosidae). Grammostola vachoni was the dominant species in hand capture and Actinopus sp. 1 in pitfall traps. The seasonal variation, diversity, and abundance of the mygalomorph community are analyzed and discussed here. The Mygalomorphae of the Tandilia system comprises an important group of sedentary and cryptozoic spiders that seem to be dependent on habitat type and environmental factors.En el presente trabajo se analizó la riqueza específica, abundancia y actividad de la comunidad de arañas Mygalomorphae en la Reserva Natural Sierra del Tigre, Buenos Aires, Argentina. Este ecosistema serrano alberga numerosas especies endémicas y es rico en fauna y flora nativa. La abundancia de arañas se muestreó mensualmente desde mayo de 2011 a mayo de 2012, mediante recolección manual y trampas de caída. Las especies registradas en el área de estudio fueron Actinopus sp. 1 (Actinopodidae), Grammostola vachoni Schiapelli y Gerschman, 1960; Plesiopelma longisternale Schiapelli y Gerschman, 1942 y Catumiri argentinense (Mello-Leitão, 1941) (Theraphosidae). Grammostola vachoni resultó la especie dominante en la recolección manual y Actinopus sp. 1 en trampas de caída. Se discuten y analizan la variación estacional, diversidad y abundancia de la comunidad de migalomorfas. Las Mygalomorphae del sistema de Tandilia comprenden un grupo importante de arañas sedentarias y criptozoicas que parecen depender del tipo de ambiente y factores ambientales.Centro de Estudios Parasitológicos y de Vectore

A comparative morphological study of the epiandrous apparatus in mygalomorph spiders (Araneae, Mygalomorphae)

Many adult male spiders have silk glands which are not associated with the spinnerets. They occur on the anterior margin of the genital furrow and are used during the building of the sperm web and sperm droplet induction. These epiandrous glands exit the body through ducts which lead to specialized spigots. In the taxon Mygalomorphae, the presence of epiandrous spigots is just reported for a couple of species but their morphology has not been investigated. In this paper we provide a detailed study of the ultrastructure morphology of eighteen species belonging to eight families using light and scanning electron microscopy (SEM). We describe and present images of the epiandrous spigots above the genital opening. Also, we compare the morphology of spigots between families and describe the epiandrous glands through histology.Centro de Estudios Parasitológicos y de Vectore

Hidden Sylvatic Foci of the Main Vector of Chagas Disease Triatoma infestans: Threats to the Vector Elimination Campaign?

Triatoma infestans, a highly domesticated species and historically the main vector of Trypanosoma cruzi, is the target of an insecticide-based elimination program in the southern cone countries of South America since 1991. Only limited success has been achieved in the Gran Chaco region due to repeated reinfestations. We conducted full-coverage spraying of pyrethroid insecticides of all houses in a well-defined rural area in northwestern Argentina, followed by intense monitoring of house reinfestation and searches for triatomine bugs in sylvatic habitats during the next two years, to establish the putative sources of new bug colonies. We found low-density sylvatic foci of T. infestans in trees located within the species' flight range from the nearest infested house detected before control interventions. Using multiple methods (fine-resolution satellite imagery, geographic information systems, spatial statistics, genetic markers and wing geometric morphometry), we corroborated the species identity of the sylvatic bugs as T. infestans and found they were indistinguishable from or closely related to local domestic or peridomestic bug populations. Two sylvatic foci were spatially associated to the nearest peridomestic bug populations found before interventions. Sylvatic habitats harbor hidden foci of T. infestans that may represent a threat to vector suppression attempts