ABSTRACT
The monotypic Peruvian genus Anqasha with type species Anqasha picta (Pocock 1903) is revised. A female of A. picta from the type locality of Caraz is herein described for the first time. The recently described females of A. picta coming from Recuay are transferred to the new taxon, which is herein described, diagnosed, and illustrated. Males of A. minaperinensis sp. nov. differ from that of A. picta in the shape of retrolateral branch of subapical apophyses on male tibia I, which is apically flattened and having three short spines. Females of A. minaperinensis sp. nov. differ from A. picta in the shape of seminal receptacles.
Se revisa el género monotípico peruano Anqasha, con la espécie tipo Anqasha picta (Pocock 1903). Se describe por primera vez una hembra de A. picta de la localidad de tipo en Caraz. Las hembras recientemente descritas de A. picta procedentes de Recuay son transferidas al nuevo taxon, el cual se describe, diagnostica e illustra aquí. Los machos de A. minaperinensis sp. nov. se differencían de A. picta en la forma de la rama retrolateral de la apófísis subapical en la tibia I del macho, la cual está aplanada apicalmente y llevando tres espinas cortas. Las hembras de A. minaperinensis sp. nov. se differencían de A. picta en la forma de los receptaculos seminales.
ABSTRACT
Resumen Se describe, diagnostica e ilustra Neischnocolus iquitos sp. nov. de la región de Loreto, Perú. Los machos de N. iquitos sp. nov. se diferencian del resto de sus congéneres conocidos a la fecha por tener dos apófisis retrolaterales en la tibia palpal, en combinación con la presencia de una quilla retrolateral en el émbolo, y la ausencia de granulación o micropicos en el émbolo o tegulum. Las hembras de N. iquitos sp. nov. se diferencian de las otras hembras de Neischnocolus en la morfología de la genitalia, consistiendo de una parte inferior esclerotizada con dos receptáculos seminales separados, y una parte superior transparente y con muescas.
Abstract Neischnocolus iquitos sp. nov. from Loreto region, Peru, is described, diagnosed and figured. Males of N. iquitos sp. nov. differ from all known congeners in the presence of two retrolateral processes on palpal tibia, in combination with the presence of a retrolateral keel on embolus and the absence of granulation or microspikes on embolus or tegulum. Females of N. iquitos sp. nov. differ from all known Neischnocolus females in the morphology of the genitalia consisting of a lower sclerotized part with two short, separate seminal receptacles, and an upper part, which is transparent and notched.
ABSTRACT
Resumen Los estudios de la araneofauna en los agroecosistemas son cruciales para la implementación de las arañas como agentes potenciales de control biológico de plagas. En este trabajo se analiza la distribución del ensamble de arañas en los microhábitats (follaje, tronco y suelo) de los cultivos de Citrus sinensis, (Rutaceae) de la Provincia de Corrientes, Argentina. Los muestreos se realizaron mensualmente mediante cuatro técnicas de captura: agitación de follaje, tamizado de hojarasca, pitfall y captura manual. En total se obtuvieron 2 160 muestras y 7 194 ejemplares de arañas (2 462 en follaje, 983 en tallo y 3 749 en suelo) pertenecientes a 35 familias y 200 especies de Araneomorphae. Hubo diferencias significativas en la estructura de las comunidades de arañas de los tres microhábitats y entre los meses, según el análisis de similitud (ANOSIM). El follaje presentó mayor diversidad, seguido por el suelo y el tronco. Araneidae, Theridiidae y Salticidae predominaron en el follaje; las especies dominantes fueron: Jessica erythostoma y Cheiracantium inclusum, esta araña es una de las principales depredadoras de las larvas de Phyllocnistis citrella (Lepidoptera) que atacan las hojas de Citrus. En el tronco abundaron: Tetragnathidae, Hersiliidae y Theridiidae, destacándose Iviraiva pachyura, una especie especialista en dicho microhabitat; y Leucauge venusta la cual consideramos que es una especie oportunista, debido a que su abundancia se incrementa notablemente en sitios modificados por el hombre. En el suelo abundaron: Lycosidae, Linyphiidae y Coriniidae; Lycosa erythrognatha fue la especie dominante, seguida de Pardosa plumipedata. El índice de similitud Chao-Jaccard fue mayor entre el follaje y el tronco (J-C = 0.95), asimismo el ordenamiento Escalado Multidimencional no Métrico (NMDS) mostró una clara diferenciación de la composición de especies del suelo con respecto al follaje y al tronco. Además, en el suelo hubo mayor recambio temporal de especies y el método de seriación resultó significativo (z = 3.82, P = 0 .00) por lo tanto hubo una sucesión de especies durante el año de muestreo. Las especies en cada microhabitat probablemente evitan la competencia al utilizar distintas estrategias de caza y recursos ecológicos, además de patrones específicos de distribución temporal. Nuestros resultados sugieren que las modificaciones del ambiente, como en estos cultivos de C. sinensis, tienden a albergar varias poblaciones de arañas que se adaptaron a dicho cambio e interactúan de manera equilibrada en espacio y tiempo.(AU)
Abstract Arachnofauna studies from agroecosystems are crucial for implements spider as biological control agents. In this work we analyze the distribution of spider assemblages at three microhabitats (canopy, tree trunk and soil) in Citrus sinensis orchards (Rutaceae) in the Province of Corrientes, Argentina. Spiders were collected monthly using four sampling techniques: beating foliage, leaf litter sifting, pitfall traps and direct capture by hand. A total of 2 160 samples were examined and 7 194 spiders were collected (2 462 on the canopy, 983 on trunk and 3 749 on the floor) belonging to 34 families and 200 species/ morphospecies of Araneomorphae. There were significant differences among microhabitats and months in the structure of the spider communities, according to analysis of similarity (ANOSIM). The diversity was highest on the canopy, followed by soil and tree trunk. Araneidae, Salticidae and Anyphaenidae were the most abundant taxa in the canopy; the dominant species were Jessica erythostoma and Cheiracanthium inclusum, a predator of the leaf herbivore Phyllocnistis citrella (Lepidoptera) a pest of Citrus spp. The most abundant families on the tree trunk were Tetragnathidae, Hersiliidae and Theridiidae, Iviraiva pachyura was a species specialist in such microhabitat; and Leucauge venusta was an opportunistic species, because their abundance increaseds markedly in anthropic environments that modified by man. The most abundant families on the floor were Lycosidae, Linyphiidae and Coriniidae. In this habitat, Lycosa erythrognatha and Pardosa plumipedata were dominant species. The Chao-Jaccard similarity index was highest between the canopy and trunk (J-C = 0.95), likewise ordination by nonmetric multidimensional scaling (NMDS) revealed strong differentiation between assemblages of soil spiders and canopy and trunk spiders. Also, on the soil the temporary replacement of species was greater and the seriation method was significant (z = 3.82, P = 0.00) therefore there was a succession of species during the year. The different species in each microhabitat probably avoided competition by using different hunting strategies and different ecological resources, in addition to specific patterns of temporal distribution. Our results suggest that anthropic environments, such as in Citrus orchards, tend to harbor populations of spiders able to adapt to those environments and interact in a balanced way in space and time.(AU)
Subject(s)
Spiders , Pest Control, Biological , Ecosystem , Citrus sinensis , Sustainable Agriculture , ArgentinaABSTRACT
ABSTRACT: The post embryonic developmental stages of Marpissa bengalensis (Araneae; Salticidac), the 2nd most abundant predatory species in citrus orchard were collected from the experimental fruit garden, department of Horticulture, located at the campus of University of Agriculture Faisalabad andstudied. Life cycle was observed in the laboratory, which started from egg sac collected from the field along with gravid female and released into the spider cages. The incubation period ranged from 5-15 days. The average eggs hatched were 23.8 eggs/cocoon and hatching % under laboratory conditions was recorded as 73.18%. The average duration of spiderlings span on their mothers back was 7 days. An overall, mean duration of 3rd spiderling stage was of 7.46 days. All spiderlings hatched from 8 cocoons. At the 4th spiderling stage, the average duration was of 10.23 days. In the 5th spiderling stage, the spiderling spent an average of 19.82 days. The 6th and 7th spiderlings stages lasted a total of 23.14 days and 25.86 days respectively. During 8th spiderling stage, the duration was maximum and it was recorded in 28.08 days. On average, from hatching to adult stage, the spiderlings lasted 137 days to attained maturity. Greater mortality was observed in the 3rd and 4th spiderling stages, decreasing thereafter and reaching zero in the 8th spiderling stage.
RESUMO: Os estádios de desenvolvimento pós-embrionário de Marpissa bengalensis (Araneae; Salticidac), a segunda espécie predatória mais abundante no pomar cítrico, foram coletadas no pomar experimental de frutas do Departamento de Horticultura, localizado no campus da Universidade de Agricultura de Faisalabad, onde foram estudados. O ciclo de biológico foi estudado no laboratório, em que iniciou a partir de ovos coletados de fêmeas grávidas e soltas em cativeiro. O período de incubação variou de 5-15 dias. a média de ovos incubados foram 23,8 ovos/casulo e a porcentagem de incubação em condições laboratoriais foi de 73,18%. A duração média da fase imatura a foi de 7 dias. Uma duração geral, média do terceiro estádio da fase imatura, foi de 7,46 dias de todas as fases imaturas incubadas com 8 casulos. A partir do quarto estádio da fase imatura a duração média foi de 10,23 dias. No quinto estádio de imaturação, demorou uma média de 19,82 dias. O sexto e o sétimo estádios de imaturação duraram um total de 23,14 e 25,86 dias, respectivamente. Durante o oitavo estádio de imaturação a duração foi de 28,08 dias, sendo máxima. Em média, desde a incubação até o estádio adulto, o estádio de imaturação duraram 137 dias. A maior mortalidade foi observada nos terciro e quarto estádios de imaturação, diminuindo, a partir de então, e atingindo zero no oitavo estádio de imaturação.
ABSTRACT
ABSTRACT A list of spider species is presented for the Belém Area of Endemism, the most threatened region in the Amazon Basin, comprising portions of eastern State of Pará and western State of Maranhão, Brazil. The data are based both on records from the taxonomic and biodiversity survey literature and on scientific collection databases. A total of 319 identified species were recorded, with 318 occurring in Pará and only 22 in Maranhão. About 80% of species are recorded at the vicinities of the city of Belém, indicating that sampling effort have been strongly biased. To identify potentially high-diversity areas, discounting the effect of variations in sampling effort, the residues of a linear regression between the number of records and number of species mapped in each 0.25°grid cells were analyzed. One grid, representing the Alto Turiaçu Indigenous land, had the highest deviation from the expected from the linear regression, indicating high expected species richness. Several other grid cells showed intermediate values of the regression residuals, indicating species richness moderately above to the expected from the model.
Subject(s)
Animals , Spiders/classification , Biodiversity , Brazil , Population Density , GeographyABSTRACT
The male of Bistriopelma matuskai Kaderka 2015 is described and illustrated, the species is rediagnosed and complemented by new biogeographical data. Additionally, a new species of Bistriopelma, B. titicaca sp. nov., from the Puno region in Peru is described, diagnosed and illustrated. An updated general description and distribution map of Bistriopelma are provided
Se describe e ilustra el macho de Bistriopelma matuskai Kaderka 2015, se presenta una nueva diagnosis de la especie junto con nuevos datos biogeográficos. Adicionalmente, se describe, diagnostica e ilustra una nueva especie de Bistriopelma, B. titicaca sp. nov., del departamento de Puno en Perú. Se provee una descripción general actualizada y un mapa de distribución para el género
ABSTRACT
Bistriopelma gen. nov. from the Andean region in Peru is here described, diagnosed and illustrated, together with two new species Bistriopelma lamasi sp. nov. as a type species and Bistriopelma matuskai sp. nov. This new genus differs from all other theraphosid genera, except the genus Phrixotrichus Simon 1889 (sensu Perafán & Pérez-Miles 2014) and the troglobite species Tmesiphantes hypogeus Bertani, Bichuette & Pedroso 2013, in the presence of two abdominal dorsolateral patches of the type III urticating setae. Bistriopelma gen nov. can be distiguished from Phrixotrichus by the different shape of spermathecae in females, consisting of two separate subparallel seminal receptacles in Bistriopelma gen. nov. but strongly divergent in Phrixotrichus and by the different morphology of male palpal bulb (embolus projecting retrolaterally from tegulum in Bistriopelma gen. nov. against posteriorly in Phrixotrichus); furthermore by the presence of basal spine on prolateral tibial apophysis, the absence of the type IV urticating setae and paired tarsal claws denticulate. Bistriopelma gen. nov. is separated from Tmesiphantes hypogeus by the position of the urticating seta patches (middle of abdomen in Bistriopelma gen. nov. and posterior half in Tmesiphantes hypogeus), the different shape of spermathecae (long separate seminal receptacles with subapical constriction in Bistriopelma gen. nov. and short, subtriangular and widely separated in Tmesiphantes hypogeus) and also in the extension of metatarsal scopulae. Additional comments and a distribution map of all species of this genus are provided.
Se describe, diagnostica e ilustra Bistriopelma gen. nov. de la región andina de Perú, con dos nuevas especies Bistriopelma lamasi sp. nov., especie tipo, y Bistriopelma matuskai sp. nov. Este género nuevo se diferencia del resto de arañas terafosidas, excepto el género Phrixotrichus Simon 1889 (sensu Perafán & Pérez-Miles 2014) y la especie cavernícola Tmesiphantes hypogeus Bertani, Bichuette & Pedroso 2013, en la presencia de dos manchas abdominales dorsolaterales de las setas urticantes de tipo III. Bistriopelma gen nov. se diferencia de Phrixotrichus en la morfología de la espermateca, estando compuesta en Bistriopelma gen. nov. de dos receptaculos seminales separados y subparalelos pero considerablemente divergentes en Phrixotrichus, en la morfología de los bulbos pedipalpales de machos (émbolo proyectándose retrolateralmente del tegulum en Bistriopelma gen. nov. contra posteriormente en Phrixotrichus); además en la presencia de la espina basal en la apófisis tibial prolateral, en la ausencia de las setas urticantes de tipo IV y en las uñas tarsales con dientes. Se diferencia de Tmesiphantes hypogeus en la posición de los parches de las setas urticantes (centro del abdomen en Bistriopelma gen. nov. y parte posterior en Tmesiphantes hypogeus), en la morfología de las espermatecas (receptáculos seminales prolongados y separados, subapicalmente estrechados en Bistriopelma gen. nov. y cortos, subtriangulares y considerablemente separados en Tmesiphantes hypogeus) y también en la extensión de las escopulas metatarsales. Se presentan comentarios adicionales y el mapa de distribucion de todas las especies de este género.
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Ami armihuariensis sp. nov. from Cuzco region, Peru is described, diagnosed and figured. Males of Ami armihuariensis sp. nov. differ from all other congeners, except A. pijaos, by the presence of only one retrolateral process on male palpal tibia, from A. pijaos by the granulation in tegular area of male palpal bulb. Additionally, photographs of A. yupanquii spermatheca are for the first time presented in order to emphasize the characteristic shape of spermathecae in this genus.
Se describe, diagnostica e ilustra Ami armihuariensis sp. nov. de la región de Cuzco, Perú. Los machos de Ami armihuariensis sp. nov. se diferencian del resto de sus congéneres, excepto A. pijaos, por tener una sola apófisis retrolateral en la tibia pedipalpal y de A. pijaos por la granulación en el área tegular de los bulbos pedipalpales de los machos. Adicionalmente, se presentan por primera vez fotografía de la espermateca de A. yupanquii para resaltar la forma característica de las espermatecas en este género.
ABSTRACT
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 7 174 specimens were collected (33 families, 44 genera and 200 species/morphospecies). The AM1 recorded 3 811 individuals (33 families, 179 species/morphospecies) and AM2 3 363 individuals (31 families, 174 spe- cies/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 web- builders (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 irrigation.
Las arañas son ideales como indicadores de cambios ecológicos por su diversidad y abundancia. En la provincia de Corrientes, Argentina, se estudiaron arañas de Citrus sinensis en parcelas de 0.82 hectáreas, con riego (AM1) y sin riego (AM2). Mediante pitfall, agitación de follaje, captura manual y tamizado de hojarasca se recolectaron 7 174 ejemplares (33 familias, 44 géneros y 200 especies/morfoespecies), el 70% fueron juveniles. AM1 registró 3 811 individuos (33 familias, 179 especies/morfoespecies) y AM2 3 363 (31 familias, 174 especies/morfoespecies). Durante el verano se observó la mayor abundancia. En ambas parcelas, ocho familias representaron el 75% del total, Lycosidae fue la más numerosa y se identificaron ocho gremios; las vagabundas de suelo fueron las más abundantes (AM1 n=1341, s=39; AM2 n=999, s=33) seguida por las constructoras de telas orbiculares (AM1 n=637, s=36; AM2 n=552, s=33), las cazadoras al acecho (AM1 n=471, s=43; AM2 n=453, s=47) y las de telas espaciales (AM1 n=446, s=23; AM2 n=342, s=25. La diversidad alfa en ambas parcelas (AM1 H’=4.161, J’=0.802; AM2 H’=4.184, J’=0.811) no mostró diferencias significativas (t=1.083, p=0.279). El modelo de dependencia lineal fue el que mejor ajustó los resultados. El modelo de Clench estimó el 90.9% de las observadas en AM1 y el 90.6% en la AM2.
Subject(s)
Animals , Biodiversity , Citrus sinensis/parasitology , Spiders/classification , Argentina , Population DensityABSTRACT
Se estudió la distribución vertical de arañas asociadas a árboles de Quercus humboldtii y Clusia spp. con diferentes modelos arquitecturales en el Santuario de Fauna y Flora Iguaque, Colombia. Se seleccionaron árboles de cada modelo arquitectural, estratificándolos verticalmente cada tres metros desde la base hasta el dosel. Se realizaron colectas en cada estrato por 20 minutos durante el día y en la noche. También se tomaron muestras en la parcela aledaña (4 m²). Se colectaron 1261 individuos pertenecientes a 104 morfoespecies y 20 familias; las familias más frecuentes fueron Theridiidae, Salticidae, Araneidae, Linyphiidae, Anyphaenidae y Theridiosomatidae. Se encontraron diferencias en la distribución vertical de arañas en cuanto a la abundancia, la riqueza, la composición, la distribución de sexos y las épocas climáticas atribuibles a las arquitecturas vegetales y a su estratificación. Clusia presentó la comunidad de arañas más diversa, Quercus la de mayor dominancia. La composición estuvo influida por las lluvias, el período del día y la disponibilidad de soportes vegetales.
The vertical distribution of spiders associated to trees of Quercus humboldtii and Clusia spp. with different architectural model, was studied at Sanctuary of Fauna and Flora of Iguaque; for this, we selected trees of each architectural model, stratified them each three m in high starting at the base to the canopy of the tree. We took samples in each stratus for 20 min during the day and at night. Also, we took samples in the nearest ground plot (4 m²). We collected 1,261 specimens of 104 morphospecies and 20 families. The most frequent families were Theridiidae, Salticidae, Araneidae, Linyphiidae, Anyphaenidae, and Theridiosomatidae. We observed differences in the spiders' vertical distribution in abundance, richness, composition, time period, and sex ratio, all of them attributable to plant architectures and its stratification. Clusia spider community was the most diverse, Quercus spider community was the riechest. Rain, period of time at day, and support availability affected the spiders' composition.
ABSTRACT
First remarks on the nesting biology of Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) in the Azapa valley, northern Chile. Some aspects about the nesting biology of the potter wasp Hypodynerus andeus (Packard, 1869) are reported for the first time. Observations were carried out at the Azapa valley, coastal desert of northern Chile. A total of sixty nests were collected and examined, each composed by 1-14 cells, most of them found attached to concrete lamp posts. The only preys recorded in the cells were Geometridae (Lepidoptera) caterpillars and the presence of the parasitoid Anthrax sp. (Diptera, Bombyliidae) was also recorded. A number of arthropods belonging to different groups, mainly spiders, were found occupying empty nests.
Primeiras observações sobre a biologia da nidificação de Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) no vale de Azapa, norte do Chile. Alguns aspectos da biologia da nidificação da vespa Hypodynerus andeus (Packard, 1869) são registrados pela primeira vez. As observações foram conduzidas no vale de Azapa, deserto litoral do norte do Chile. Sessenta ninhos foram coletados e examinados, cada um composto por 1-14 células. A maioria dos ninhos estava aderida a postes de concreto. As únicas presas registradas nas células foram larvas de Geometridae (Lepidoptera). Um parasitóide, Anthrax sp. (Diptera, Bombyliidae), foi também registrado. Vários artrópodes, principalmente aranhas, foram encontrados utilizando ninhos vazios.
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The silk egg case and orb web of spiders are elaborate structures that are assembled from a number of components. We analysed the structure, the amino acid and fibre compositions, and the tensile properties of the silk fibres of the egg case of Nephila clavata. SEM shows that the outer and inner covers of the egg case consist of thick, medium and thin silk fibres. The silk fibres of the outer cover of the egg case are probably produced by the major and minor ampullate glands. The silk fibres of the inner cover of the egg case from cylindrical glands appears to be distinct from the silk fibres of the major ampullate glands based on their micro-morphology, mole percent amino acid composition and types, and tensile behaviour and properties. Collectively, our investigations show that N. clavata uses silk fibres from relatively few glands in varying combinations to achieve different physical and chemical properties (e.g., color, diameter, morphology and amino acid composition) and functional and mechanical properties in the different layers of the egg case.
ABSTRACT
Effect of spiders (Arachnida: Araneae) as predators of insect pest in alfalfa crops (Medicago sativa) (Fabaceae) in Argentina. Spiders are predators that reduce insect pest populations in agroecosystems. Trials were conducted to measure the selectivity against different insect preys, the daily consumption, effect of predators alone and together with a known number of preys, and the indirect effect of predators on vegetation. For this, experimental units (1x1m) were used covered with a fine plastic mesh. Misumenops pallidus, Oxyopes salticus and Araneus sp. were used as generalist predators, and aphids, weevils, locusts, chrysomelids and Lepidoptera larvae as their potential preys. Among the preys offered, the spiders preferred Lepidoptera larvae compared to the other two pests groups (weevils and aphids). The maximum consumption rate was of 93.33% for Lepidoptera larvae, 25.33% for aphids and 11.67% for weevils. The Q Index values for the three species of spiders showed a positive selectivity only for defoliating larvae. O. salticus showed the highest values of consumption rates while Rachiplusia nu was the most consumed. The maximum value of consumption in 24 hours was showed by O. salticus on R. nu (C)=2.8. The association of several species of predatory spiders increased the total number of insects captured, and also showed that the addition of spiders caused a decrease in the number of leaves damaged by the effect of lepidopterous larvae. Rev. Biol. Trop. 59 (4): 1651-1662. Epub 2011 December 01.
Las arañas son depredadoras capaces de reducir las poblaciones de insectos plaga en agroecosistemas. Para medir la selectividad frente a distintas presas, se realizaron ensayos de consumo diario, efecto de los depredadores aisladamente y en conjunto sobre el número de presas y efecto indirecto de los depredadores sobre la vegetación; se utilizaron jaulas experimentales de 1x1m cubiertas con una fina malla plástica. Misumenops pallidus, Oxyopes salticus y Araneus sp. fueron utilizadas como depredadores generalistas, áfidos gorgojos, larvas de lepidópteras, crisomélidos y ortópteros como sus presas potenciales. Las arañas prefirieron larvas de lepidópteros frente a curculiónidos y áfidos. El consumo máximo de larvas de lepidópteros fue de 93.33%, áfidos 25.33% y curculiónidos 11.67%. El Índice Q para las tres especies de arañas demostró una selectividad positiva sólo para las larvas defoliadoras. O. salticus presentó las tasas de consumo mayores. Rachiplusia nu fue la especie más consumida. El valor máximo de consumo registrado en 24h fue para O. salticus frente a R. nu (C)=2.8. La asociación de varias especies de arañas depredadoras incrementó el total de insectos capturados. La presencia de arañas provocó la disminución del número de hojas dañadas por el efecto de las larvas de lepidópteros plaga.
Subject(s)
Animals , Insecta/classification , Medicago sativa/parasitology , Pest Control, Biological/methods , Predatory Behavior/physiology , Spiders/physiology , Argentina , Food Preferences/physiology , Larva/classificationABSTRACT
Neste trabalho são apresentadas informações oriundas de um banco de dados das aranhas descritas e registradas para a região neotropical entre 1757 e 2008. O enfoque será na diversidade do grupo no Estado de São Paulo, comparado com outros estados brasileiros. Os resultados são oriundos de mais de 25.000 registros publicados em artigos científicos na Região Neotropical. Estes dados permitem avaliar a distribuição atual do grupo, identificar lacunas de coleta, definir biomas prioritários para estudo e até delimitar áreas de endemismo para o Brasil no futuro. O Estado de São Paulo apresenta 875 espécies descritas, distribuídas em 50 famílias. A região neotropical possui 11.280 espécies (quase 1/3 das espécies propostas para o mundo). O Brasil é o país neotropical com maior diversidade (3.203 spp.), seguido do México (1.951 spp.) e Panamá (1.325 spp.). Na América do Sul temos atualmente mais de 7.500 espécies de aranhas e o Brasil apresenta a maior diversidade (3.203 espécies registradas em 72 famílias), seguido da Argentina (1.316 spp.) e Peru (1.066 spp.).
In this study we present a database of spiders described and registered from the Neotropical region between 1757 and 2008. Results are focused on the diversity of the group in the State of São Paulo, compared to other Brazilian states. Data was compiled from over 25,000 records, published in scientific papers dealing with Neotropical fauna. These records enabled the evaluation of the current distribution of the species, the definition of collection gaps and priority biomes, and even future areas of endemism for Brazil. A total of 875 species, distributed in 50 families, have been described from the State of São Paulo. A total of 11,280 species have been recorded from the Neotropical region (almost 1/3 of the species described worldwide). Brazil is the Neotropical country with the highest diversity (3,203 spp.), followed by Mexico (1,951 spp.) and Panama (1,325 spp.). Seven thousand five hundred species were recorded from South America and Brazil holds the highest diversity (3,203 spp., in 72 families), followed by Argentina (1,316 spp.), and Peru (1,066 spp.).
ABSTRACT
Four Cerrado Biome phytophysiognomies (palm tree woodlands, primary semi-deciduous dry forest, secondary semi-deciduous dry forest and Cerrado stricto sensu), at Nazareth Farm (Municipality of José de Freitas, State of Piauí) were sampled using beating tray and pitfall traps. All the collected individuals during the structured protocol and those previously collected in the study area (occasional sampling with pit-fall traps with drift fences) were identified together. A total of 1215 spiders, 40 families and 114 species were sampled. Only 38 species were sampled during the structured inventory. The estimate species richness curves reached from 47 (Bootstrap) to 124 (Chao2) species. The secondary semi-deciduous dry forest harbored the highest spider abundance (n = 221) and species richness (19 spp.). This is the first study to compare these vegetation types, too characteristic in the North of Piauí, and assuredly threatened by the agricultural advance in this state. The spider species richness found at Nazareth Farm is the second higher recorded from Piauí.
Quatro fitofisionomias do Bioma Cerrado (mata dos cocais, mata seca semi-decídua primária, mata seca semi-decídua secundária e cerrado típico) na Fazenda Nazareth (Município de José de Freitas, Piauí) foram amostradas utilizando-se guarda-chuva entomológico e armadilhas de queda. Os indivíduos coletados a partir do protocolo estruturado e aqueles coletados previamente na área de estudo (amostragens ocasionais com armadilhas de interceptação e queda) foram identificados unificadamente. Um total de 1215 aranhas, 40 famílias e 114 espécies foram amostradas. Somente 38 espécies foram amostradas no durante o inventário padronizado. As curvas de riqueza de espécies estimadas variaram entre 47 (Bootstrap) e 124 (Chao2) espécies. A mata seca semi-decídua secundária exibiu maior abundância de aranhas (221 indivíduos) e riqueza em espécies (19 spp.). Este é o primeiro estudo comparando estas fitofisionomias, comuns no Norte do Piauí, e indubitavelmente ameaçadas pelo avanço da agricultura no estado. A riqueza em espécies de aranhas encontrada na Fazenda Nazareth é a segunda maior registrada para o Estado do Piauí.
ABSTRACT
Spider community (Arachnida, Araneae) of alfalfa crops (Medicago sativa) in Buenos Aires, Argentina. Over the last decades there has been an increasing interest in the use of natural enemies to control pest insects, including spiders. We studied a spider community in Argentina by sampling every two weeks during 2004-2006 in one-hectare lots. Soil stratum spiders were collected using nets and pitfall traps. A total of 6229 specimens were collected (15 families and 50 species). Seven families were found in the herbal stratum, the most abundant were Thomisidae (n=2012, 32.30%), Araneidae (n=1516, 24.33%) and Oxyopidae (n=604, 9.70%). The soil had 14 families, mainly: Lycosidae (n=629, 10.10%) and Linyphiidae (n=427, 6.85%). Hunting spiders predominated: ambushers (32.99 %); stalkers (11.77%) and ground-runners (10.84%) were less common. The most abundant web building spiders were the orb weavers (27.56%). The diversity indexes were: H´=2.97, Dsp=0.11 and J=0.79, evidencing a moderately diverse spider community with predominance of Misumenops pallidus, Oxyopes salticus, Lycosa poliostoma and L. erythrognatha. The spiders were present throughout the phenological development of the crop with abundance peaks in spring and summer. Rev. Biol. Trop. 58 (2): 757-767. Epub 2010 June 02.
En las últimas décadas se ha dado un interés creciente en el uso de enemigos naturales para controlar plagas de insectos, como arañas. Se estudió una comunidad de arañas en Argentina mediante un muestreo cada dos semanas durante el periodo 2004-2006 en lotes de una hectárea. En el estrato del suelo las arañas fueron colectadas con redes de arrastre y trampas de caída. Se recolecto un total de 6 229 ejemplares (15 familias y 50 especies). Siete familias se encuentran en el estrato herbáceo, las más abundantes fueron: Thomisidae (n=2 012, 32.30%), Araneidae (n=1 516, 24.33%) y Oxyopidae (n=604, 9.70%). El suelo habían 14 familias, principalmente: Lycosidae (n=629, 10.10%) y Linyphiidae (n=427, 6.85%). Predominaron las arañas cazadoras: por emboscadas (32.99%), al acecho (11.77%), corredoras de suelo (10.84%) y tejedoras orbiculares (27.56%). Los índices de diversidad fueron: H´=2.97, Dsp=0.11 y J=0.79, evidenciando una comunidad de arañas moderadamente diversa, con predominio de Misumenops pallidus, Oxyopes salticus, Lycosa poliostoma and L. erythrognatha. Las arañas estuvieron presentes durante el desarrollo fenológico del cultivo con picos de abundancia en primavera y verano.
Subject(s)
Animals , Biodiversity , Medicago sativa , Spiders/classification , Argentina , Population Density , SeasonsABSTRACT
A technique is proposed for individually marking orb-web spiders aiming at facilitating the identification of the individuals on their webs. To check the efficiency of the method, 17 females and 30 males of Nephila clavipes (Linnaeus 1767) were marked on the dorsal part of the opisthosoma using enamel applied through a disposable syringe. Success was obtained in marking 47 individuals; no death, dispersal or agonistic behavior was observed after the use of the method. This marking did not dissolve in contact with water, resisted the expansion of the opisthosoma and was lost only in the ecdysis. This method also was efficient for males that, being smaller than the females, demand a more careful methodology
Propõe-se uma técnica de marcação individual de aranhas orbitelas visando facilitar a identificação dos indivíduos em suas teias. Para verificar a eficiência do método, 17 fêmeas e 30 machos de Nephila clavipes (Linnaeus, 1767) foram marcados na parte dorsal do abdômen utilizando-se esmalte, aplicado por meio de seringa descartável. Obteve-se sucesso na marcação dos 47 indivíduos, não sendo observada morte, dispersão ou comportamentos agonísticos após o uso do método. Esta marcação não dissolveu em contato com a água, resistiu ao aumento do opistossoma e foi perdida somente na ecdise. Esse método também foi eficiente para os machos que, por serem menores que as fêmeas, exigem uma metodologia mais cuidadosa.
Subject(s)
Animals , Male , Female , Sex Differentiation , Spiders , MethodsABSTRACT
Composition of the Araneae (Arachnida) fauna of the provincial Iberá Reserve, Corrientes, Argentina. A survey of the spider community composition and diversity was carried out in grasslands and woods in three localities: Colonia Pellegrini, Paraje Galarza and Estancia Rincón (iberá province Reserve). Pit fall traps, leaf litter sifting, foliage beating, hand collecting and sweep nets were used. Shannons diversity index, evenness, Berger-Parkers dominance index, ß and 
diversity were calculated, and a checklist of spider fauna was compiled. Species richness was estimated by Chao 1, Chao 2, first and second order Jack-knife. A total of 4 138 spiders grouped into 150 species from 33 families of Araneomorphae and two species from two families of Mygalomorphae were collected. Five species are new records for Argentina and eleven for Corrientes province. Araneidae was the most abundant family (39.8%), followed by Salticidae (10.9%), Anyphaenidae (7.9%), Tetragnathidae (7.4%), and Lycosidae (5.5%). The other families represented less than 5% of the total catch. The web-builder guild had the highest number of specimens and the highest richness index. The abundance, observed richness, Shannon diversity and evenness indexes were highest in Colonia Pellegrini woodland and Paraje Galarza grassland. Alpha diversity represented 89% of the gamma; the remaining 11% corresponded to ß diversity. According to the indexes, between 67% and 97% of the existing spider fauna was represented in the collected specimens from iberá. Rev. Biol. Trop. 57 (1-2): 339-351. Epub 2009 June 30.
Se estudió la composición y diversidad de la comunidad de arañas de la Reserva provincial iberá, Corrientes, Argentina. Se realizaron capturas en bosque y pastizal en Colonia Pellegrini, Paraje Galarza y Estancia Rincón por medio de las técnicas de muestreo: trampas "pit-fall", tamizado, golpeteo de follaje, observación directa y red de arrastre. Las arañas se agruparon en gremios y se compiló un inventario. La similitud entre localidades y unidades ambientales se midió con el índice de Jaccard, y se calcularon los índices de diversidad de Shannon, equitabilidad, dominancia de Berger-Parker, y la diversidad beta y gamma. Para estimar la riqueza de especies se utilizó Chao 1, Chao 2, Jackknife 1 y 2. En total se recolectaron 4 138 arañas, se identificaron 33 familias y 150 especies de Araneomorphae, y dos familias y dos especies de Mygalomorphae. Cinco especies son nuevos registros para Argentina y 11 para la provincia de Corrientes. Araneidae fue la familia más abundante (39.8%), seguida por Salticidae (10.9%), Anyphaenidae (7.9%), Tetragnathidae (7.4%), Lycosidae (5.5%), y las restantes familias representaron menos del 5% de la captura total. El gremio de arañas tejedoras de telas orbiculares fue el de mayor abundancia y riqueza de especies. Entre las unidades ambientales, la mayor abundancia, riqueza y diversidad se verificó en el bosque de Colonia Pellegrini y en el pastizal de Paraje Galarza. La diversidad a fue alta, representó el 89% de la diversidad gamma, y la diversidad ß constituyó el 11% restante. Según los diferentes índices se capturó entre el 67% y el 97% de las especies que están presentes en la Reserva.
Subject(s)
Animals , Biodiversity , Spiders/classification , Argentina , Population DensityABSTRACT
The first case of envenoming by Latrodectus geometricus in Venezuela is described. The accident occurred at the victims home, in Aragua de Barcelona, Anzoátegui State. The 31-year-old female victim was bitten twice on the left scapular region, in quick succession (within seconds). She developed a hyperactive state of the central, autonomic and peripheral nervous systems with minor local symptoms.
Descreve-se o primeiro caso de envenenamento por Latrodectus geometricus na Venezuela. O acidente ocorreu na residência, em Aragua de Barcelona, Estado Anzoátegui. A paciente de 31 anos de idade foi picada, consecutivamente duas vezes, em segundos, na região escapular esquerda. Ela desenvolveu um quadro de hiperatividade do sistema nervoso central, autonômico e periférico com escassa sintomatologia local.
Subject(s)
Adult , Animals , Female , Humans , Spider Bites/epidemiology , Black Widow Spider , Spider Venoms/poisoning , Spider Bites/drug therapy , Venezuela/epidemiologyABSTRACT
O estudo objetivou o levantamento da fauna de aranhas e ácaros com hábito predador, em copas de tangerineiras (Citrus deliciosa var. Montenegrina) em pomar orgânico, situado em Montenegro, RS. Durante um ano, quinzenalmente 24 plantas eram sorteadas e avaliadas em duas regiões da copa, utilizando-se um pano-de-batida (1 m²). Capturou-se o total de 3.129 indivíduos, sendo 2.559 aranhas e 570 ácaros. Em Araneae foram reconhecidas 53 espécies adultas distribuídas em oito famílias, dentre estas, as mais abundantes foram Sphecozone sp. (Linyphiidae) (21,8 por cento) e Chrysso pulcherrima (Mello-Leitão) (Theridiidae) (9,9 por cento). No outono observou-se a maior abundância de jovens e adultos (29,2 por cento) e, na primavera, a maior riqueza de espécies (40). Na primavera também se registraram os maiores valores para os índices de Margalef e Shannon-Wiener, este último, porém, não diferiu significativamente dos das demais estações. Os valores de Simpson, em todas as estações foram semelhantes, indicando o mesmo grau de dominância das espécies. Em Acari registraram-se oito espécies, distribuídas em três famílias, as mais abundantes foram Leptus sp.1 (Erythraeidae) (59,4 por cento) e Amblyseius saopaulus Denmark & Muma (Phytoseiidae) (30 por cento). O outono foi a estação mais rica em número de espécies (oito). No inverno observou-se a maior abundância de indivíduos (47 por cento) e, no verão, a menor (0,88 por cento). Entre os ácaros, Phytoseiidae apresentou a maior riqueza. Entre as aranhas, Anyphaenidae foi a que apresentou a maior abundância e Theridiidae, a maior riqueza de espécies, seguindo assim o padrão já observado para o grupo.
A survey was conducted to study the spider and predatory mite fauna occurring in the canopies of tangerine trees (Citrus deliciosa Tenore, cultivar Montenegrina) of an organically managed orchard, at Montenegro County, RS. During a year, fortnightly, 24 randomly trees were selected and sampled in two canopies areas, by using a sheet of white cloth (1 m²). A total of 3,129 arachnids were collected, being 2,559 spiders and 570 mites. Based on the adults, 53 species of Araneae were recognized, belonging to eight families. Among those, the most abundant were Sphecozone sp. (Linyphiidae) (21.8 percent) and Chrysso pulcherrima (Mello-Leitão) (Theridiidae) (9.9 percent). Autumn exhibited the greatest abundance of young and adults of Araneae (29.2 percent) and spring was the season richest in species (40). Margalef and Shannon-Wiener diversity indexes also showed the highest values in spring. The latter index did not show differences among seasons. Simpson complementary index was equal among seasons, reflecting the same degree of species dominance. In Acari, eight species were identified in three families. The most abundant species were the mites Leptus sp.1 (Erythraeidae) (59.4 percent) and Amblyseius saopaulus Denmark & Muma (Phytoseiidae) (30 percent). Autumn was the season richest in mite species (eight). The highest abundance (47 percent) was observed on winter and the lowest (0.88 percent) on summer. Among mites, Phytoseiidae showed the highest richness. Among the spiders, Anyphaenidae was the most abundant and Theridiidae had the highest species richness, following the patterns observed for the group.