999 resultados para Ecologia do cerrado
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Résumé: Great traveller and tireless observer, the Sicilian poet and writer Bartolo Cattafi was trying to escape from his land for his whole life, which was conducted paradoxically autour de sa chambre, but also travelling through islands and continents, where he found inspiration for his poetry and prose. For this reason, his literary contribution, which never betrayed his poetic nature and reporter character, gives an added value to the modern ulyssic dimension. The latter considers travelling as an essential life step and it is closely related to the concept of attachment to its own land. These two perspectives, often met in his different «isole lontane», define the career of this singular migrant figure. Initially he moves to Milan to fulfil the need to find a job. Later he will find in his own Sicily the harmony and the serenity he has been looking for in the course of his travels. The writings collected in 2008 and object of this study reveal interesting affinities to those published in the "Mondadori" series edited by his good friend Vittorio Sereni and that explain part of the works belonging to the Sicilian author, clarifying his topoi and obsessions.
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This paper presents a five years survey of endoparasitoids obtained from the larvae of frugivorous Tephritidae and Lonchaeidae flies. The insects were reared from cultivated and wild fruits collected in areas of the cerrado in the State of Mato Grosso do Sul, Brazil. The flies obtained from 14 host fruit species were eight Anastrepha species, Ceratitis capitata (Wiedemann, 1824) (Tephritidae); Dasiops sp. and Neosilba spp. (Lonchaeidae). Eleven parasitoid species were collected: Braconidae - Asobara anastrephae (Muesebek, 1958), Doryctobracon areolatus (Szépligeti, 1911), D. fluminensis (Costa Lima, 1938), Opius bellus Gahan, 1930 and Utetes anastrephae (Viereck, 1913); Figitidae - Aganaspis nordlanderi Wharton, 1998, Lopheucoila anastrephae (Rhower, 1919), Odontosema anastrephae (Borgmeier, 1935) and Trybliographa infuscata Gallardo, Díaz & Uchôa-Fernandes, 2000 and, Pteromalidae - Spalangia gemina Boucek, 1963 and S. endius Walker, 1839. In all cases only one parasitoid emerged per puparium. D. areolatus was the most abundant and frequent parasitoid of fruit fly species, as was L. anastrephae in Neosilba spp. larvae. This is the first record of A. nordlanderi in the midwestern Brazilian region.
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The oviposition behaviour of the braconid parasitoid, Compsobracon mirabilis ( Szépligeti, 1901) is described. Observations were conducted in a cerrado region located in Três Marias, Minas Gerais, Brazil. The oviposition occurred in a branch of Alibertia concolor (Cham.) K. Schum. 1889 (Rubiaceae), inside of which there were thirteen larvae of an unidentified species of Lepidoptera.
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Em Julho de 2004, foram observados adultos de G. semirufa atacando larvas de Peckia Robineau-Desvoidy, 1830 enquanto estas se alimentavam de carcaça de porco Sus scrofa em área de cerrado. Em Dezembro do mesmo ano, no mesmo local, larvas de terceiro instar de P. trivittata foram coletadas em outra carcaça de porco e levadas ao laboratório. As larvas foram criadas em condições naturais. Das 31 pupas obtidas, emergiram 19 adultos de G. semirufa e seis adultos de P. trivittata, correspondendo a uma prevalência de 61% de parasitismo.
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Com o objetivo de descrever a composição, ocorrência temporal e aspectos ecológicos das espécies de larvas de Lepidoptera associadas a cinco espécies de plantas: Erythroxylum ovalifolium e E. subsessile (Erythroxylaceae), Manilkara subsericea (Sapotaceae), Protium icicariba e P. heptaphyllum (Burseraceae), 1.455 plantas foram vistoriadas durante o período de Julho de 2003 a Agosto de 2005 no Parque Nacional da Restinga de Jurubatiba (PNRJ). Foram encontradas 32 espécies de Lepidoptera associadas a essas cinco espécies de plantas hospedeiras, sendo que as quatro espécies mais abundantes pertenciam à família Elachistidae. Manilkara subsericea apresentou o maior número de espécies de Lepidoptera associadas, 14 espécies, seguida por E. ovalifolium, com 10 espécies, P. icicariba, com sete, E. subsessile com seis e P. heptaphyllum com duas espécies de Lepidoptera associadas. Apenas uma das 32 espécies de Lepidoptera criadas apresentava hábito gregário e 56% utilizavam algum tipo de abrigo para alimentação e/ou defesa. Seis espécies de Lepidoptera identificadas (27%) eram polífagas, três (14%) oligófagas e 13 (59%) tiveram apenas uma única espécie de planta hospedeira registrada. As espécies mais abundantes de mariposas apresentaram dois períodos reprodutivos no ano, predominantemente, no inverno e outono. Fatores abióticos, como a forte insolação na primavera e verão na formação aberta de restinga, podem ser importantes determinando esse padrão temporal de reprodução dos insetos, mas não podemos descartar também fatores bióticos como a pressão de inimigos naturais.
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The seasonal characteristics of the Cerrado region strongly influence food resource predictability and vegetal tissue nutritional content. The aims of this work were to record the abundance and temporal distribution of Gonioterma exquisita Duckworth, 1964 (Lepidoptera, Elachistidae) and its relation with phenological, physical, and chemical traits of the host plant Byrsonima pachyphylla Griseb. (Malpighiaceae). Four nutritional quality parameters were determined for new and mature leaves: gross protein and nitrogen content, dry matter, and in vitro digestibility. We inspected 200 plants per month, searching for G. exquisita caterpillars. About 35.8% of the 2,400 plants inspected presented caterpillars, with an abundance peak in the wet season. Caterpillar abundance was positively correlated with mature leaf availability, their food resource. Although mature leaves presented lower gross protein and nitrogen contents than new leaves, this difference was small during the abundance peak of G. exquisita.
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Este trabalho apresenta uma lista de dípteros sarcofagídeos adultos coletados em carcaça de porco Sus scrofa, em área de Cerrado, Distrito Federal, Brasil, sendo um estudo sobre a composição da fauna de Diptera na região. O trabalho de campo acompanhou o processo de decomposição da carcaça e foi realizado durante 45 dias. A partir de 4.626 indivíduos coletados foram identificadas 28 espécies, sendo 16 novos registros para a região estudada.
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O presente trabalho teve como objetivos descrever o padrão de variação espacial na coloração de N. lar no Parque Nacional da Restinga de Jurubatiba e estudar aspectos da sua ecologia e de seu comportamento. O trabalho foi realizado de fevereiro de 2003 a maio de 2004, em excursões bimestrais a quatro diferentes áreas do parque, vistoriando um total de 120 plantas de Byrsonima sericea, um de seus principais hospedeiros. Foram encontrados quatro tipos de coloração (amarelo, rosa, laranja e branco), sendo que nem todas as formas ocorreram juntas no mesmo local. Quase todos os machos adultos observados em campo apresentaram coloração amarela, com exceção de um indivíduo alaranjado. Já as fêmeas apresentaram todos os padrões de cores citados. Cruzamentos realizados em laboratório demonstraram que indivíduos de diferentes colorações e/ou diferentes áreas copulam normalmente entre si, indicando não haver barreira mecânica ou comportamental que impeça a cópula entre as diferentes formas. Adultos de N. lar ocorreram o ano todo, apresentando as maiores abundâncias entre outubro e fevereiro, e as mais baixas, entre abril e agosto. Tanto a porcentagem de ocupação das plantas, quanto a densidade de indivíduos de N. lar nas plantas acompanharam o padrão de sua flutuação populacional. Assim, parece que N. lar apresenta uma estação reprodutiva por ano, entre os meses de outubro e fevereiro, época coincidente com a estação chuvosa e emissão de ramos novos pela planta de alimentação.
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The prevalence of Cuterebra simulans bot fly parasitism on marsupial Gracilinanus microtarsus was compared between sexes and seasons of the year. No significant difference was observed between females and males but prevalence was higher in warm-wet season than cool-dry season. This pattern agree with observations of others studies with oestrids flies in southern Neotropical areas, suggesting the occurrence of latitudinal change in the peak of bot flies reproductive activity related to seasons of the year along these systems. This is the first record of C. simulans larvae parasitism on G. microtarsus and its occurrence in southern areas of the Neotropical region.
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A transmissão da doença de Chagas ocorre, principalmente, por meio de fezes de hemípteros hematófagos (Triatominae), os quais ingerem o Trypanosoma cruzi ao se alimentarem do sangue de pessoas ou outros mamíferos infectados. Para o controle dos triatomíneos, os piretróides são os principais inseticidas utilizados. Entretanto, algumas populações de insetos demonstraram resistência a determinados piretróides, indicando a necessidade do desenvolvimento de novos inseticidas eficazes no controle desses vetores. Assim, foi avaliada a atividade inseticida de 83 extratos vegetais, pertencentes a 35 espécies diferentes, em ninfas do primeiro estádio de Dipetalogaster maxima (Uhler, 1894) (Hemiptera: Reduviidae), triatomíneo encontrado no México. Para o teste tópico, foram aplicados 50 ìg de cada extrato nos tergitos abdominais de dez ninfas, em duplicata. Como controles, foram utilizados insetos tratados com etanol, acetona ou sem nenhum tipo de tratamento. Os triatomíneos foram observados durante 28 dias. Nenhum extrato apresentou atividade inseticida significativa, entretanto, o extrato hexânico do fruto e o etanólico da casca do caule de Simarouba versicolor (Simaroubaceae) inibiram a taxa de ecdise em D. maxima (40% e 25%, respectivamente). Sugere-se que estes extratos sejam quimicamente investigados e monitorados por ensaios biológicos a fim de determinar os componentes, para que estes possam ser utilizados como modelos moleculares ou como compostos biorracionais nos programas de controle de insetos.
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We present the first data on the nesting biology of Megalopta aegis and M. guimaraesi from southeastern Brazil. Nests were collected in the Área de Proteção Ambiental Água Limpa, Bauru, São Paulo state. Our data suggest that nest architecture is conserved throughout all species of Megalopta. Two nests of M. guimaraesi consisted of a single female with brood. Of three M. aegis nests, two contained single females with brood and the third nest contained three adult females, with three times more brood than any single female nest. This observation suggests that social behavior in M. aegis is facultative, as known for other Megalopta species.
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A survey of bat flies was carried out in the Brazilian savanna (Cerrado) in the Goiás state, Brazil. We collected 227 specimens of seventeen species belonging to nine genera of Streblidae and seven specimens of four species of Basilia Miranda-Ribeiro, 1903 (Nycteribiidae). Except for Paratrichobius longicrus (Miranda-Ribeiro, 1907) (Streblidae), all species are new recorded in Goiás.
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Seasonality in insect abundance in the "Cerrado" of Goiás State, Brazil. Many studies have provided evidence that tropical insects undergo seasonal changes in abundance and that this is partly due to alternation between the dry and rainy seasons. In the Brazilian "Cerrado" (savannah), this season alternation is particularly evident. The purpose of this work was to study the seasonal abundance of insects in a "Cerrado" area in the municipality of Pirenópolis, Goiás State, Brazil. The insects were captured fortnightly using a light trap between September 2005 and August 2006. The insects collected were separated at the order level and counted. Faunistic analysis was performed to select the predominant insect orders, a multiple linear regression to examine the relation between climatic variables (temperature and precipitation) with the abundance of insects and a circular distribution analysis to evaluate the existence of seasonality in the abundance of insect orders. A total of 34,741 insect specimens were captured, belonging to 19 orders. The orders with the greatest number of specimens were Hymenoptera (8,022), Coleoptera (6,680), Diptera (6,394), Lepidoptera (6,223), Isoptera (2,272), Hemiptera (2,240) and Trichoptera (1,967), which represent 97.3% of all the specimens collected. All the orders, except for Diptera, Isoptera and Trichoptera, showed a relationship with the climate variables (temperature), and all the orders, except for Diptera, presented a grouped distribution, with greater abundance in the transition from the end of the dry season (September) to the start of the rainy one (October/November). A discussion about seasonality on the abundance of the insects is presented.
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Forensic Entomology research has been concentrated in only a few localities of the "Cerrado" vegetation, the Brazilian Savannah. The present study had, as its objective, an examination of the diversity of arthropod fauna associated with the carcasses of Sus scrofa (Linnaeus) in this biome. The study was conducted during the dry and humid periods in two Cerrado vegetation profiles of the State of Minas Gerais. The decaying process was slower and greater quantities of arthropods were collected during the dry period. Insects represented 99% of 161,116 arthropods collected. The majority of these were Diptera (80.2%) and Coleoptera (8.8%). The entomofauna belong to 85 families and at least 212 species. Diptera were represented by 31 families and at least 132 species. Sarcophagidae (Diptera) and Scarabaeidae (Coleoptera) were the richest groups. Oxysarcodexia (Sarcophagidae) presented the largest number of attracted species, however none of these species bred in the carcasses. The Coleoptera collected belong to at least 50 species of 21 families. Among these species, Dermestes maculatus and Necrobia rufipes were observed breeding in the carcasses. This study showed species with potential importance for estimating the postmortem interval (PMI), indicative of seasonal and environmental type located.