790 resultados para LEPIDOPTERA


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The genus Trichogramma Westwood (Hymenoptera: Trichogrammatidae) includes insect egg parasitoids that are widely used throughout the world as control agents of pest insects. The aim of this study was to identify the species of Trichogramma naturally associated with the eggs of lepidopteran pests of the following agricultural and horticultural crops: collards, Brassica oleracea L. (Brassicales: Brassicaceae); papaya, Carica papaya L. (Capparales: Caricaceae); tomato, Lycopersicon esculentum Mill. (Solanales: Solanaceae); cassava, Manihot esculenta Crantz (Malpighiales: Euphorbiaceae); banana, Musa sp. L. (Zingiberales: Musaceae); passion fruit, Passiflora sp. Degener (Malpighiales: Passifloraceae); sugarcane, Saccharum sp. L. (Poales: Poaceae); and corn (maize), Zea mays L. (Poales: Poaceae); and an invasive species (Sodom?s apple milkweed, Calotropis procera Aiton; Gentianales: Apocynaceae) in the semiarid region of Minas Gerais, Brazil. We report natural parasitism by Trichogramma in eggs of Agraulis vanillae vanillae (L.) (Lepidoptera: Nymphalidae), Antichloris eriphia F. (Lepidoptera: Arctiidae), Danaus sp. (L.) (Lepidoptera: Nymphalidae), Diatraea saccharalis F. (Lepidoptera: Crambidae), Erinnyis ello L. (Lepidopera: Sphingidae), and Protambulyx strigilis L. (Lepidopera: Sphingidae). In total, 2,242 specimens of Trichogramma were obtained, belonging to the species T. pretiosum Riley, T. manicobai Brun, Moraes & Soares, T. marandobai Brun, Moraes & Soares, and T. galloi Zucchi. These species of Trichogramma may be candidates for biological control programs of lepidopteran pests in the semiarid region of Minas Gerais and in other semiarid regions.

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Astilbin was isolated in high yield from Dimorphandra mollis, and its insecticidal and growth inhibiting activity by stomach ingestion were evaluated against Anticarsia gemmatalis and Spodoptera frugiperda. The insecticidal activity of astilbin, the weight reduction of the larval phase and the prolongation of the larval and pupal phases were verified for both species. Astilbin was identified on the base of its NMR, MS and physical data. (C) 2002 Society of Chemical Industry.

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The quality and extent of the 'matrix' in terrestrial fragmented landscapes may influence the persistence and behaviour of patch-associated fauna. Butterflies are a popular target group for fragmentation studies and represent an ideal assemblage to explore the impact and role of the matrix in patchy landscapes. To date, there has been no attempt to synthesise available research and assess the extent to which the matrix is included in studies of fragmented butterfly populations. Addressing this issue is important for improved understanding of habitat use in fragmented landscapes, and for the successful management and conservation of butterfly biodiversity. Our systematic review of 100 empirical research papers spans 50 years, and identifies how (and indeed if) the matrix is recognised in studies of butterfly populations in fragmented landscapes. We found that it was significantly more likely for studies not to include the matrix in their experimental design. This is of particular concern given 60 % of papers that excluded the matrix in their research did so in systems where the matrix was expected to contain resources of value for patch-associated species (as it was either a heterogeneous landscape or had similar structure to patches). Of the papers that did consider the matrix, 80 % (n = 24) reported a negative effect of the matrix on butterfly species and/or communities. Matrix effects may influence the survival and persistence of faunal groups in a world increasingly dominated by fragmented habitats. Our review suggests that future research should clearly define the matrix, and incorporate it in appropriate experimental designs.

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Population density can play a vital role in determining investment in reproductive behaviours and morphologies of invertebrates. Males reared in high-density environments, where competition is high but difficulties in locating mates are low, may invest more in reproductive structures associated with sperm competition such as testes, at the expense of those traits associated with mate location, such as antennae. In species where females advertise for mates, such as most moths, a high-density environment may also lead to a reduction in pheromonal signalling (calling) length and frequency as a result of high mate abundance. While such responses have been shown at the phenotypically plastic level in moths, heritable evolutionary adaptations have seldom been tested, and studies of how population density influences pheromone signalling strategies are scarce. Here we use behavioural assays and scanning electron microscopic measurements to test whether larval population density influences, at the genetic level, the ability of males to locate females and male investment into antennal morphology, in addition to its effect on the frequency and duration of female calling. We used two replicated populations of the Indian meal moth Plodia interpunctella that had experimentally evolved under high or low population densities for 35 generations. We found no significant divergence in antennal morphology or mate acquisition behaviours between the two density populations. These findings suggest that although population density has the ability to create plastic changes in both morphological and behavioural traits, this factor alone is unlikely to be causing evolutionary change in male and female signalling in this species.

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La relación entre el liderazgo y emprendimiento es un tema de estudio y análisis relativamente nuevo. El término de liderazgo ha sido estudiado y enfocado a otras áreas de estudio, pero en cuanto a la relación existente con emprendimiento se presentan aún carencias conceptuales. A lo largo del presente estudio, se hace una revisión de la literatura la cual permite identificar y analizar estos conceptos y su relación en la última década en Colombia, consultando literatura comprendida en bases de datos en línea tales como, Redalyc, Scielo y Dialnet. En este documento, se destacan los atributos de un emprendedor y de un líder, igualmente se recogen los modelos de emprendimiento, las teorías de liderazgo, y los elementos que caracterizan cada concepto. Finalmente, se evidencia una dicotomía entre el líder y el emprendedor y se concluye que el liderazgo es una característica intrínseca del emprendimiento; sin embargo, el liderazgo no es por regla utilizado para emprender.

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Esse estudo teve como objetivo determinar quais espécies de Helicoverpa estão atualmente associadas ao broqueamento de tomate na região do Planalto Central Brasileiro.

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In this work we compare Grapholita molesta Busck (Lepidoptera: Tortricidae) populations originated from Brazil, Chile, Spain, Italy and Greece using power spectral density and phylogenetic analysis to detect any similarities between the population macro- and the molecular micro-level. Log-transformed population data were normalized and AR(p) models were developed to generate for each case population time series of equal lengths. The time-frequency/scale properties of the population data were further analyzed using wavelet analysis to detect any population dynamics frequency changes and cluster the populations. Based on the power spectral of each population time series and the hierarchical clustering schemes, populations originated from Southern America (Brazil and Chile) exhibit similar rhythmic properties and are both closer related with populations originated from Greece. Populations from Spain and especially Italy, have higher distance by terms of periodic changes on their population dynamics. Moreover, the members within the same cluster share similar spectral information, therefore they are supposed to participate in the same temporally regulated population process. On the contrary, the phylogenetic approach revealed a less structured pattern that bears indications of panmixia, as the two clusters contain individuals from both Europe and South America. This preliminary outcome will be further assessed by incorporating more individuals and likely employed a second molecular marker.

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Grapholita molesta (Lepidoptera: Tortricidae) é uma das principais pragas do pessegueiro no Brasil, causando perdas de 3-5% da produção. Dentre os agentes de controle biológico Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) tem sido encontrado nos pomares de pessegueiros. O objetivo deste trabalho foi estudar a criação de T. pretiosum em ovos de G. molesta e Anagasta kuehniella (Lepidoptera: Pyralidae) e selecionar as linhagens de T. pretiosum com potencial de controle de G. molesta. A seleção de linhagens foi realizada com cinco populações de T. pretiosum coletadas em pomares de pessegueiro cultivados sob o sistema orgânico de produção. O estudo foi realizado em condições controladas de temperatura (25 ± 2°C), umidade relativa (70 ± 10%) e fotofase (14h). Ovos de G. molesta são hospedeiros adequados ao desenvolvimento de T. pretiosum uma vez que, nas variáveis estudadas número de ovos parasitados, porcentagem de parasitismo e razão sexual, os valores foram equivalentes aos criados em ovos de A. kuehniella . O maior parasitismo de ovos de G. molesta ocorreu com posturas de até 48h de desenvolvimento embrionário. Das linhagens de T. pretiosum coletadas, H08, PO8, PEL e L3M apresentaram melhor desempenho biológico, sendo, portanto, indicadas para estudos de semi-campo e campo para o controle biológico da mariposa-oriental.

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O objetivo deste trabalho foi estudar a biologia de Strepsicrates smithiana (Lepidoptera: Tortricidae) e determinar sua infestação em araçazeiro (Psidium cattleianum). Os parâmetros biológicos foram avaliados, uma tabela de vida de fertilidade foi elaborada e a infestação em um pomar de araçazeiro foi estabelecida. A duração do período ovo‑adulto foi de 43,4 dias, e a sobrevivência foi de 21,3%. As fêmeas colocaram em média 135 ovos, e a longevidade de machos e fêmeas foi de 16,5 e 17,6 dias, respectivamente. Strepsicrates smithiana aumenta 32 vezes a cada geração, e a duração média de uma geração é de 45 dias. A maior infestaçãofoi registrada em janeiro.