Exclusion of tourist species from assemblages in ecological studies: a methodological approach using spiders

Background: The exclusion of tourist species from samples is important to avoid bias in community analyses. However, in practice, this is a very difficult task. The commonly used methods by researchers, when the habitat of the species is not known, have several shortcomings: first, they exclude not only pseudo-rare species but also genuinely rare species; second, the results obtained with those methods depend on the abundance of the sampling; and third, they follow very subjective rules. The aims of this study were: (i) to propose a methodology to detect and exclude habitat-tourist species from the database used to carry out analyses in community ecology studies, (ii) to evaluate how the presence of habitat-tourist species affects the richness estimates, and (iii) to assess the effect of including juvenile spiders in the detection of tourist species and the effect of removing them from the richness estimates. Results: When the adult + juvenile dataset was considered, twenty-one habitat-tourist species were detected: 8 in forest foliage, 11 in forest leaf litter, and 2 in grassland. When habitat-tourist species were considered with this dataset, richness overestimation was significant in foliage and in leaf litter, and the final slopes of the richness estimation curves were significantly steeper in leaf litter. When only the adult dataset was considered, eight habitat-tourist species were detected: 3 in forest foliage, 4 in forest leaf litter, and just one in grassland. The inclusion of habitat-tourist species in this dataset showed an overestimation of richness, but this was not significant. Conclusions: The proposed methodology contributes to solving the problem of tourist species, which was recognized as one of the great problems in biodiversity studies. This study showed that common estimators overestimate species richness when habitat-tourist species are included, leading to erroneous conclusions. Besides, this research showed that the inclusion of juveniles (e.g. spiders) could improve the analysis outputs because it allowed the detection of more habitat-tourist species.Fil: Nadal, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; ArgentinaFil: Gonzalez, Alda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Avalos, Gilberto. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; Argentin

Técnica de control basadas en el dominio físico para sistemas LTI Mimo. : aplicación a la máquina síncrona

Tesis (Doctor en Ingeniería Eléctrica) U.A.N.L.UANLhttp://www.uanl.mx

Comunidades de Thomisidae (Araneae) en diferentes tipos de vegetación en un Sitio RAMSAR en el noreste de Argentina

The RAMSAR Chaco Wetland site is one of the three most diverse biomes in Argentina due to its very heterogeneous environment. Studies on the diversity of spiders on this biome are scarce and there is no study in relation to the diversity of Thomisidae Sundevall, 1833. We analyzed the Thomisidae assemblages in environments with different degrees of structural complexity (gallery forest -GF-, low open forest -LOF-, grassland -Grassl- and palm groves -Palm Grv-) on seven localities of RAMSAR site. The spiders were collected by foliage beating, hand collecting and vacuum sampling (G-vac). 464 individuals were collected, distributed in 34 species/morphospecies. Completeness of sampling was greater than 90% and more than 60% of the expected species were obtained according to the Chao 1 estimator. The highest abundance, richness, and diversity of order 1 and 2 were observed in the GF but these were not significant. The grassl had the lower richness, diversity and equitability. Tmarus pugnax (Mello-Leitão, 1929) dominated in the forests, while T. aff. humphreyi (Chickering, 1965) dominated in the Grassl, and Misumenops maculissparsus (Keyserling, 1891) with Uraarachne sp (Keyserling, 1880) in the Palm Grv. The NMDS separated two groups: the forests (GF and LOF) and the Grassl + Palm Grv (stress = 0.28) and the ANOSIM analysis indicated significant differences between groups (R = 0.38 p = 0.02). Likewise, the Chao-Jaccard index indicated greater similarity between forested environments and the Grassl + Palm Grv. The most richness and abundance of tomisids were obtained in forested environments, possibly due to greater plant complexity in these environments.El Sitio RAMSAR Humedales Chaco es uno de los tres biomas de mayor diversidad de Argentina, dado que presenta un ambiente muy heterogéneo. Los estudios acerca de la diversidad de arañas en dicho bioma son escasos y en relación a la diversidad de Thomisidae Sundevall, 1833 no se registra ninguno. Se analizaron las comunidades de Thomisidae en ambientes con diferentes grados de complejidad estructural (bosque de galería -SG-, bosque bajo abierto -BA-, pastizales -Pz- y palmerales -Pr-) en siete localidades del sitio RAMSAR. Las arañas fueron recolectadas mediante golpeteo de follaje, captura manual y aspirado (G-vac). Se recolectaron 464 individuos, distribuidos en 34 especies/morfoespecies. La completitud del muestreo superó el 90% y se obtuvo más del 60% de las especies esperadas según el estimador Chao 1. La mayor riqueza, abundancia y diversidad de orden 1 y 2 se observó en la SG, pero no fue estadísticamente significativo. El Pz presentó la menor riqueza, diversidad y equitatividad. Tmarus pugnax (Mello-Leitão, 1929) dominó en los bosques, mientras que T. aff humphreyi (Chickering, 1965) dominó en el Pz y Misumenops maculissparsus (Keyserling, 1891) con Uraarachne sp (Keyserling, 1880) en el Pr. El NMDS separó dos grupos: los bosques (SG y BA) y los Pz + Pr (Stress = 0.28) y el análisis ANOSIM indicó diferencias significativas entre los grupos (R = 0.38 p = 0.02). Asimismo, el índice de Chao-Jaccard indicó mayor similitud entre los ambientes boscosos y los Pz + Pr. La mayor riqueza y abundancia de tomísidos se obtuvieron en los ambientes boscosos, posiblemente se deba a la mayor complejidad de la vegetación en dichos ambientes

Spider diversity in cultures of Citrus sinensis (Rutaceae) in Corrientes province, Argentina

Spiders are predators that reduce insect pest populations in agroecosystems. In spite that the presence of spider assemblages has been described in different crop plants, no reports have been done for Citrus species in Argentina. We studied the spider community associated with cultures of Citrus sinensis in the province of Corrientes, Argentina, in two plots (AM1 irrigated and AM2 unirrigated) of 0.82 hectares each. Spiders were collected monthly by using pitfall traps, hand capture, agitation of foliage and sieving of soil litter. A total of 7174 specimens were collected (33 families, 44 genera and 200 species/morphospecies). The AM1 recorded 3811 individuals (33 families, 179 species/morphospecies) and AM2 3363 individuals (31 families, 174 species/morphospecies). November, December and January showed the highest abundance in both plots. A total of 70% of collected spiders were juveniles. Eight families were the most abundant and represented 75% of spiders collected in both plots, the largest being Lycosidae. We identified eight guilds in both plots, for which the ground runners resulted the most abundant (AM1 n=1341, s=39, n=999 AM2, s=33), followed by orb weavers (AM1 n=637, s=36; AM2 n=552, s=33), the stalkers (AM1 n=471, s=43, AM2 n=453, s=47) and the space webbuilders (AM1 n=446, s=23; AM2 n=342, s=25). The analysis of alpha diversity in both plots (AM1H’=4.161, J’=0.802; AM2 H’=4.184, J’=0.811) showed no significant differences (t=1.083 p=0.279). The linear dependences model was the one with the best fit results, where the species observed were more than estimated. Clench model estimated 90.9% of the spiders observed in the unit with irrigation and 90.6% in the unit without irrigationFil: Avalos, Gilberto. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; Argentina;Fil: Bar, María Esther. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; Argentina;Fil: Oscherov, Elena Beatriz. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; Argentina;Fil: Gonzalez, Alda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina

Food preferences of <i>Araneus uniformis</i> (Araneae: Araneidae) and <i>Jessica erythrostoma</i> (Araneae: Anyphaenidae) in laboratory conditions

Las arañas Araneus uniformis (Araneidae) y Jessica erythrostoma (Anyphaenidae) son dos de las especies más abundantes en el follaje de cultivos de Citrus sinensis. El objetivo de este trabajo fue evaluar la función de dichas arañas en el control biológico de los insectos plagas más frecuentes en estos cultivos; a ese fin, se analizaron las preferencias alimentarias de A. Uniformis y J. Erythrostoma en condiciones de laboratorio. Se utilizaron como presa los insectos más numerosos recolectados en la plantación de C. Sinensis, de los órdenes Diptera, Hemiptera, Hymenoptera, Coleoptera y Orthoptera. Se utilizó una jaula mediana, cubierta por una malla fina de plástico, que albergaba un refugio consistente en una planta joven de naranjo. Para el análisis de los resultados se utilizó el índice de preferencia α de Manly, propuesto para una población variable de presas. Según el índice de Manly, A. Uniformis tiene una preferencia alimentaria por Cicadellidae (Hemiptera), con un valor α=48,7%, seguidos por Tephritidae (Diptera) y Apidae (Hymenoptera), con α=29% y α=15%, respectivamente. Orthoptera (α=4,7%) y Coleoptera (α=2,7%) fueron poco seleccionados. Jessica erythrostoma demostró una preferencia alimentaria por Diptera (Tephritidae), cuyo promedio alcanzo un 48,7%, seguidos de Hemiptera (Cicadellidae) (α=26,7%) y Coleoptera (α=18,7%). Los Orthoptera (Acrididae) fueron poco elegidos (α=6%), mientras que ningún Hymenoptera (Apidae) fue seleccionado.The spiders Araneus uniformis (Araneidae) and Jessica erythrostoma (Anyphaenidae) are two of the most abundant species in the foliage of Citrus sinensis fields. The objective of this paper is to evaluate the functions of those spiders in the biological control of the most frequent insect pests of those fields; to that end, the alimentary preferences of A. uniformis and J. erythrostoma were analyzed in laboratory conditions. The most common insects in the C. sinensis field were collected to be used as prey, belonging to the orders Diptera, Hemiptera, Hymenoptera, Coleoptera and Orthoptera. A medium-sized cage, covered by a thin plastic mesh, with a young orange plant inside for shelter. To analyze the results, the Manly’s α preference index was used, proposed for a variable prey population. According to Manly’s index, A. uniformis has an alimentary preference for Cicadellidae (Hemiptera), with α=48.7%, followed by Tephritidae (Diptera) and Apidae (Hymenoptera) with α=29% and α =15% respectably. Orthoptera (α=4.7%) and Coleoptera (α=2.7%) were less commonly selected. Diptera, whose average was α=48.7%, followed by Hemiptera (Cicadellidae) (α=26.7%) and by Coleoptera (α=18.7%), were the orders most commonly selected by Jessica erythrostoma. Orthoptera (Acrididae) were rarely chosen, with α=6%, and no Hymenoptera (Apidae) were selected at all. Key words: Araneae, Araneidae, food preferences, laboratory conditions, Citrus, spiders in crops, natural regulators.Centro de Estudios Parasitológicos y de Vectore

Food preferences of <i>Araneus uniformis</i> (Araneae: Araneidae) and <i>Jessica erythrostoma</i> (Araneae: Anyphaenidae) in laboratory conditions

Las arañas Araneus uniformis (Araneidae) y Jessica erythrostoma (Anyphaenidae) son dos de las especies más abundantes en el follaje de cultivos de Citrus sinensis. El objetivo de este trabajo fue evaluar la función de dichas arañas en el control biológico de los insectos plagas más frecuentes en estos cultivos; a ese fin, se analizaron las preferencias alimentarias de A. Uniformis y J. Erythrostoma en condiciones de laboratorio. Se utilizaron como presa los insectos más numerosos recolectados en la plantación de C. Sinensis, de los órdenes Diptera, Hemiptera, Hymenoptera, Coleoptera y Orthoptera. Se utilizó una jaula mediana, cubierta por una malla fina de plástico, que albergaba un refugio consistente en una planta joven de naranjo. Para el análisis de los resultados se utilizó el índice de preferencia α de Manly, propuesto para una población variable de presas. Según el índice de Manly, A. Uniformis tiene una preferencia alimentaria por Cicadellidae (Hemiptera), con un valor α=48,7%, seguidos por Tephritidae (Diptera) y Apidae (Hymenoptera), con α=29% y α=15%, respectivamente. Orthoptera (α=4,7%) y Coleoptera (α=2,7%) fueron poco seleccionados. Jessica erythrostoma demostró una preferencia alimentaria por Diptera (Tephritidae), cuyo promedio alcanzo un 48,7%, seguidos de Hemiptera (Cicadellidae) (α=26,7%) y Coleoptera (α=18,7%). Los Orthoptera (Acrididae) fueron poco elegidos (α=6%), mientras que ningún Hymenoptera (Apidae) fue seleccionado.The spiders Araneus uniformis (Araneidae) and Jessica erythrostoma (Anyphaenidae) are two of the most abundant species in the foliage of Citrus sinensis fields. The objective of this paper is to evaluate the functions of those spiders in the biological control of the most frequent insect pests of those fields; to that end, the alimentary preferences of A. uniformis and J. erythrostoma were analyzed in laboratory conditions. The most common insects in the C. sinensis field were collected to be used as prey, belonging to the orders Diptera, Hemiptera, Hymenoptera, Coleoptera and Orthoptera. A medium-sized cage, covered by a thin plastic mesh, with a young orange plant inside for shelter. To analyze the results, the Manly’s α preference index was used, proposed for a variable prey population. According to Manly’s index, A. uniformis has an alimentary preference for Cicadellidae (Hemiptera), with α=48.7%, followed by Tephritidae (Diptera) and Apidae (Hymenoptera) with α=29% and α =15% respectably. Orthoptera (α=4.7%) and Coleoptera (α=2.7%) were less commonly selected. Diptera, whose average was α=48.7%, followed by Hemiptera (Cicadellidae) (α=26.7%) and by Coleoptera (α=18.7%), were the orders most commonly selected by Jessica erythrostoma. Orthoptera (Acrididae) were rarely chosen, with α=6%, and no Hymenoptera (Apidae) were selected at all. Key words: Araneae, Araneidae, food preferences, laboratory conditions, Citrus, spiders in crops, natural regulators.Centro de Estudios Parasitológicos y de Vectore

Food preferences of <i>Araneus uniformis</i> (Araneae: Araneidae) and <i>Jessica erythrostoma</i> (Araneae: Anyphaenidae) in laboratory conditions

Las arañas Araneus uniformis (Araneidae) y Jessica erythrostoma (Anyphaenidae) son dos de las especies más abundantes en el follaje de cultivos de Citrus sinensis. El objetivo de este trabajo fue evaluar la función de dichas arañas en el control biológico de los insectos plagas más frecuentes en estos cultivos; a ese fin, se analizaron las preferencias alimentarias de A. Uniformis y J. Erythrostoma en condiciones de laboratorio. Se utilizaron como presa los insectos más numerosos recolectados en la plantación de C. Sinensis, de los órdenes Diptera, Hemiptera, Hymenoptera, Coleoptera y Orthoptera. Se utilizó una jaula mediana, cubierta por una malla fina de plástico, que albergaba un refugio consistente en una planta joven de naranjo. Para el análisis de los resultados se utilizó el índice de preferencia α de Manly, propuesto para una población variable de presas. Según el índice de Manly, A. Uniformis tiene una preferencia alimentaria por Cicadellidae (Hemiptera), con un valor α=48,7%, seguidos por Tephritidae (Diptera) y Apidae (Hymenoptera), con α=29% y α=15%, respectivamente. Orthoptera (α=4,7%) y Coleoptera (α=2,7%) fueron poco seleccionados. Jessica erythrostoma demostró una preferencia alimentaria por Diptera (Tephritidae), cuyo promedio alcanzo un 48,7%, seguidos de Hemiptera (Cicadellidae) (α=26,7%) y Coleoptera (α=18,7%). Los Orthoptera (Acrididae) fueron poco elegidos (α=6%), mientras que ningún Hymenoptera (Apidae) fue seleccionado.The spiders Araneus uniformis (Araneidae) and Jessica erythrostoma (Anyphaenidae) are two of the most abundant species in the foliage of Citrus sinensis fields. The objective of this paper is to evaluate the functions of those spiders in the biological control of the most frequent insect pests of those fields; to that end, the alimentary preferences of A. uniformis and J. erythrostoma were analyzed in laboratory conditions. The most common insects in the C. sinensis field were collected to be used as prey, belonging to the orders Diptera, Hemiptera, Hymenoptera, Coleoptera and Orthoptera. A medium-sized cage, covered by a thin plastic mesh, with a young orange plant inside for shelter. To analyze the results, the Manly’s α preference index was used, proposed for a variable prey population. According to Manly’s index, A. uniformis has an alimentary preference for Cicadellidae (Hemiptera), with α=48.7%, followed by Tephritidae (Diptera) and Apidae (Hymenoptera) with α=29% and α =15% respectably. Orthoptera (α=4.7%) and Coleoptera (α=2.7%) were less commonly selected. Diptera, whose average was α=48.7%, followed by Hemiptera (Cicadellidae) (α=26.7%) and by Coleoptera (α=18.7%), were the orders most commonly selected by Jessica erythrostoma. Orthoptera (Acrididae) were rarely chosen, with α=6%, and no Hymenoptera (Apidae) were selected at all. Key words: Araneae, Araneidae, food preferences, laboratory conditions, Citrus, spiders in crops, natural regulators.Centro de Estudios Parasitológicos y de Vectore

Iberá Wetlands: diversity hotspot, valid ecoregion or transitional area? Perspective from a faunistic jumping spiders revision (Araneae: Salticidae)

In the present work, the fauna of jumping spiders or Salticidae of the Iberá Wetlands was investigated. Patterns of species richness, composition and endemism in hygrophilous woodlands and savannah parklands in ten locations covering the Iberá Wetlands were analyzed. Samples were obtained using four methods: garden vacuum, pit-fall trap, beating and litter extraction. 75 species were collected, representing one third of the known Argentine salticids. Six species are recorded for the first time for Argentina. The community structure of the investigated locations suggests that the high diversity of jumping spiders is the result of the mixing of species of adjacent ecoregions such as Humid Chaco, Atlantic forest and Espinal. The transitional character of Iberá Wetlands, in combination with no endemism in nominally identified taxa, questions the ecoregion validity of Iberá for jumping spiders. The importance of taxonomy and the use of mature spiders in ecological studies is discussed.Fil: Rubio, Gonzalo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Misiones; ArgentinaFil: Nadal, María Florencia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; ArgentinaFil: Munevar Lozano, Ana Katerinne. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Avalos, Gilberto. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; ArgentinaFil: Perger, Robert. .Colección Boliviana de Fauna; Bolivi