We studied spatial and temporal patterns of abundance of Ctenus amphora, C. crulsi, C. manauara and C. villasboasi, four syntopic species of medium-to-large sized wandering spiders that forage on the ground in a neotropical rainforest. We found temporal variation, apparently seasonal, in abundance for two of the four species. The four species are sympatric in the study area, but with very distinct spatial patterns of abundance. Ctenus amphora was more abundant in areas with sandy soil but are also common on clay soils, C. manauara and C. crulsi are the dominant species in areas with clay soil and are infrequent in sandy soils, and C. villasboasi had a more homogenous abundance in the study area. Previous studies suggested that a predator, army ants, could have an important impact on the abundance of these spiders. We estimated the frequency of attacks by army ants using pitfall traps in sandy and clay soil areas. The estimated probability of attack by army ants was higher in areas with clay soil (92% per 3 months), where all species are frequently found, than in sandy soil areas (21%), where C. crulsi and C. manauara were almost absent. However, it is still not clear if predation by army ants is a key factor that facilitates coexistence in clay soils, and this factor can not explain the difference on the dominant species between areas with different soil types. We also discuss the description of spatial patterns of abundance as a simple, but powerful, tool seldom used for preliminary studies on the coexistence of spiders.RESUMO. Nos estudamos padroes espaciais e temporais de abundancia de Ctenus amphora, C. crulsi, C. manauara e C. villasboasi, quatro especies sintopicas de aranhas errantes que forrageiam no chao em uma floresta neotropical umida. Nos encontramos uma variagao temporal, aparentemente sazonal, na abundafancia de duas das quatro especies. As quatro especies sao simpatricas na area de estudo, mas com padroes espaciais de abundancia muito distintos. Ctenus amphora foi mais abundante em areas de solos arenosos, mas tambem foi comum em solos argilosos C manauara e C. crulsi foram as especies domi= nantes em solos argilosos, e foram infreqiientes em solos arenosos, e C. villasboasi teve uma abundancia mais homogenea na area de estudo. Estudos anteriores sugeriram que um predador, formigas de correigao, poderia ter um forte impacto sobre a abundancia destas aranhas. Nos estimamos a freqiiencia de ataques por formigas de correi^ao usando armadilhas de fosso (pitfall traps) em areas de solo arenoso e argiloso. A probabilidade estimada de ataques por formigas de correi^ao foi maior em ^eas de solo argiloso (92% em 3 meses), onde todas as especies sao freqiientemente encontradas, que em solo arenoso (21%), onde C crulsi e C. manauara foram raras. Entretanto, ainda nao esta claro se a preda 9 ao e um fator chave para facilitar a coexistencia em solos argilosos, e este fator nao pode explicar a diferenga de especies dominantes entre as &eas com tipos de solo diferentes. Nos tambem discutimos a descrigao de padr...
We studied temporal variation in adult size and sexual size dimorphism (SSD) of seven hunting spider species, Ctenus amphora, C. crulsi, C. manauara, C. villasboasi (Ctenidae), Phoneutria fera, P. reidyi (Ctenidae), and Ancylometes rufus (Pisauridae) in a tropical rainforest, and one species from a relatively open vegetation habitat, C. minor, in central Amazonia. Size variation was great within and among field trips. Spiders were generally smaller in October (end of dry season) when compared with other months: adults of C. amphora, C. crulsi and C.
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Society for the Study of Amphibians and Reptiles is collaborating with JSTOR to digitize, preserve and extend access to Journal of Herpetology. Mauremys annamensis: Vietnam (CAS-SU 9142 [syntype of merkleni]; Columbus Zoo live specimen [apparently the specimen photographed in Pritchard, 1979]; MNHN 1948-39 [syntype of merkleni]; NMW 23394 [holotype, photograph only, provided by Franz Tiedemann]; UF 87177-85; and WPM 1-7 [alive]). M. c. caspica: Iraq (FMNH 19708-09, 74949); Iran (FMNH 73495, 141619); Syria (FMNH 73494); and Turkey (FMNH 82663-66). M. c. rivulata: Greece (UMMZ 65472-78, 70191). M. "guangxiensis": China, Guangxi Prov. (SNHM 88701, holotype; and 88702, paratype; photographs only, provided by Jianqiang Cen). M. iversoni: China, Fujian Prov. (UF 71865-66; and WPM, 10 live specimens). M. "iversoni": China, Fuizhou Prov. (WPM, 1 live specimen). M. japonica: Japan (CAS-SU 15825-29, 16038, 26123, 26125-26; UF 49426; and USNM 9551, 34066-75). M. leprosa: Morocco (FMNH APPENDIX 1 Specimens Examined Mauremys annamensis: Vietnam (CAS-SU 9142 [syntype of merkleni]; Columbus Zoo live specimen [apparently the specimen photographed in Pritchard, 1979]; MNHN 1948-39 [syntype of merkleni]; NMW 23394 [holotype, photograph only, provided by Franz Tiedemann]; UF 87177-85; and WPM 1-7 [alive]). M. c. caspica: Iraq (FMNH 19708-09, 74949); Iran (FMNH 73495, 141619); Syria (FMNH 73494); and Turkey (FMNH 82663-66). M. c. rivulata: Greece (UMMZ 65472-78, 70191). M. "guangxiensis": China, Guangxi Prov. (SNHM 88701, holotype; and 88702, paratype; photographs only, provided by Jianqiang Cen). M. iversoni: China, Fujian Prov. (UF 71865-66; and WPM, 10 live specimens). M. "iversoni": China, Fuizhou Prov. (WPM, 1 live specimen). M. japonica: Japan (CAS-SU 15825-29, 16038, 26123, 26125-26; UF 49426; and USNM 9551, 34066-75). M. leprosa: Morocco (FMNH 199761-64, 197887-88); Portugal (KU 144273); Spain (CM 51038, 53367, 54682, 55331, 55501, 55675 [4 specimens]); and Tunisia (CM 54543). M. mutica: China, lower Yangtze basin (AMNH 31065; WPM, 1 live specimen); China, Guangdong Prov. (MVZ 23937-38); China, Si River basin (WPM, 9 live specimens); China, between Si River and Vietnam border (UF 87134-35; WPM, 3 live specimens); China, Hainan Island (AMNH 30154, 30157-60, 30164-66, 30168; BMNH 1929.7.3.5; FMNH 6588-90, 6592, 15905; and WPM, 3 live specimens); China, no further data (BMNH 1947.3.5.34 [holotype], 1987.1183]; Taiwan (AMNH 84519; BMNH 1922.16.5-7 [3 specimens]; and FMNH 127181-82, 127184,127187,127189-93,127195,127197-202); Vietnam, near China border (UF 87133; WPM, 8 live specimens; ZMH R00274 [photograph in Petzold, 1963]); and Japan, Ryukyu Islands (BMNH 1933.5.19.1-2 [2 specimens]; CAS-SU 2...
Despite the importance of citriculture in Brazil, very little is known about mite populations in citrus crops in the Northern Region. In the municipality of Manaus, 12 sprayed sweet orange orchards were surveyed every two weeks during seven months to record mite species amount, and to describe the abundance and distribution of the most important species. The size and age of the orchards varied from 3,360 to 88,080 m 2 and seven to 25 years, respectively. In the fourteen sampling period, leaves, twigs and fruits were collected from 12 trees, one per orchard. In total, 3,360 leaves, 672 twigs and 1,344 fruits were sampled from 168 trees. Mites were manually extracted from the fruits, and by the washing method on leaves and twigs. We identified pests with the potential to cause economic loss. Fourteen species of phytophagous and mycophagous mites from Eriophyidae, Tarsonemidae, Tenuipalpidae, and Tetranychidae were recorded. Brevipalpus phoenicis (Geijskes 1939) and Phyllocoptruta oleivora (Ashm., 1879), the two commonest phytophagous mites in other Brazilian regions were dominant, showing that local orchards are susceptible to their infestation. Eleven predatory mites were recorded, comprising 10% of the mite population, belonging to Phytoseiidae and Ascidae. Phytoseiidae was the richest family, with ten species. The results are discussed in relation to the temporal variation aspects and habitat use of the most important species. Long-term research encompassing chemical applications followed by evaluations of the mite community are necessary for a better management of the orchards, taking into consideration the seasonal phenology of key pests. KEYWORDS: Brevipalpus, phytophagous mites, predatory mites, Phyllocoptruta. Ácarofauna de Citrus sinensis L. Osbeck no Estado do Amazonas, Brasil RESUMOApesar da importância da citricultura no Brasil, pouco se conhece sobre as populações de ácaros em plantações de citros no norte do país. No município de Manaus, 12 pomares de laranja doce pulverizados foram avaliados a cada duas semanas, durante sete meses, para o registro de ácaros plantícolas e para descrever a abundância e a distribuição das espécies mais importantes. O tamanho e a idade dos pomares variaram de 3.360 a 88.0080 m 2 e de sete a 25 anos, respectivamente. Nos 14 períodos de coleta, folhas, galhos e frutos foram coletados de uma árvore em cada pomar. No total, 3.360 folhas, 672 galhos e 1.344 frutos foram coletados de 168 árvores. Os ácaros foram extraídos dos frutos manualmente e pelo método de lavagem nas folhas e galhos. Identificamos espécies pragas com potencial de causar danos econômicos. Registramos 14 espécies de fitófagos em quatro famílias (Eriophyidae, Tarsonemidae, Tenuipalpidae, and Tetranychidae). Brevipalpus phoenicis (Geijskes 1939) (Tenuipalpidae) e Phyllocoptruta oleivora (Ashm., 1879) (Eriophyidae), as duas espécies fitófagas mais abundantes em outras regiões, foram dominantes, mostrando que a cultura de citros local é suscetível à infestação. Registramos 11 espécies de predadores d...
RESUMOCtenus é um gênero de aranhas errantes abundante em florestas tropicais da América do Sul e da África e está se tornando um organismo modelo para compreensão da biologia de predadores na fauna de serapilheira. Avaliamos os efeitos da fragmentação florestal sobre quatro espécies de aranhas errantes do gênero Ctenus (C. amphora, C. crulsi, C. manauara e C. villasboasi), baseado nas variações das densidades e nos tamanhos de adultos em fragmentos de tamanhos diferentes, nas bordas destes e nas florestas secundárias próximas. Este estudo foi realizado de fevereiro a julho de 1999, em floresta tropical úmida de terra firme ao norte de Manaus -AM. As áreas incluíram três locais de mata secundária, quatro fragmentos de 1 ha, três de 10 ha, dois de 100 ha e quatro reservas em floresta contínua (maior que 10.000 ha). As aranhas foram capturadas manualmente, mensuradas e contadas em transectos de 250x5 m ou 500x5 m em áreas de platô, no interior e nas bordas dos fragmentos. Houve predomínio significativo de fêmeas em duas espécies (C. amphora-74% e C. crulsi-65%); dimorfismo sexual de tamanho em três espécies (C. amphora, C. crulsi e C. manauara) e variação temporal da abundância significativa para as quatro espécies. Estes resultados corroboraram e complementaram tendências de estudos anteriores e permitem uma interpretação mais completa sobre a ecologia destas espécies. Não observamos diferenças de abundância das aranhas entre centro e bordas e entre reservas de diferentes tamanhos. O efeito de borda ou do tamanho do fragmento sobre o tamanho de aranhas Ctenus neste estudo foi bem menor que as variações anteriormente observadas entre habitats diferentes no interior da floresta. Comparações com um estudo posterior a este, mostram que efeito da fragmentação nesta escala sobre estas aranhas diminui com a regeneração da floresta ao redor dos fragmentos, indicando uma rápida resposta do grupo para estas modificações ambientais.PalavRaS-chavE: Aranhas errantes, Ctenus, Populações, Amazônia, Fragmentos Florestais. Populations of Ctenus wandering spiders in Amazonian forest fragments aBSTRacTCtenus is a genus of wandering spiders abundant in Neotropical and African rainforests and is becoming a model organism to understand the biology of predators in the leaf litter fauna. We compared abundance, sex ratio, seasonality and size dimorphism in populations of four species of medium sized wandering spiders, Ctenus amphora, C. crulsi, C. manauara and C. villasboasi in primary forests, fragments with different areas, their borders and secondary forests near them. This study was conducted between February and July 1999, in a terra-firme (non-flooded) tropical rain forest, in central Amazonia. The spiders were measured and counted in transects of 250x5 m or 500x5 m in three secondary forest sites, four fragments of primary forest of 1 ha, three of 10 ha, two of 100 ha and four reserves of continuous forest (larger than 10.000 ha). There was a significant predominance of females in two species (C. amphora-74% and C. crulsi-65%), se...
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