736 research outputs found
Larval dispersal of Spodoptera frugiperda strains on Bt Cotton: a model for understanding resistance evolution and consequences for its management.
High dispersal of Lepidoptera larvae between non-Bt and Bt cotton plants can favour the evolution of insect resistance; however, information on host acceptance of neonates in tropical transgenic crops is scarce. Therefore, the purposes of this study were as follows: (i) to investigate the feeding behaviour of susceptible and Cry1F-resistant strains of Spodoptera frugiperda (J.E. Smith) on Bt and non-Bt cotton (Gossypium hirsutum L.) varieties and (ii) to understand the possible effects of cotton field contamination on the dispersal and infestation capacity of S. frugiperda larvae by using an individualbased model. The main results of this paper are as follows: (1) the highest post-feeding larval dispersal of the Cry1F-resistant strain occurred at an exposure time of 18?24 h; (2) via video tracking assays, we found that the least distance moved was by larvae resistant to Cry1F on non-Bt cotton; and (3) the model indicated differences in mobility capacity between Bt and non-Bt cotton. We conclude that resistant neonates exhibit sedentary behaviour. Our report represents the first findings concerning the fitness cost of larval behaviour traits of S. frugiperda associated with Cry1F resistance in Brazilian populations.Publicado online em 23 de novembro de 2017
Bi-dimensional multiscale entropy: Relation with discrete Fourier transform and biomedical application
The multiscale entropy (MSE1D) measure is now widely used to quantify the complexity of time series. The development of complexity measures for images is also a long-standing goal. Recently, the bi-dimensional version of MSE1D has been proposed (MSE2D) to analyze images. The interpretation of MSE2D curves and the applications to real data are still emergent. Because the coarse-graining step in the MSE2D computation changes the frequency content of the image, we hypothesized a possible dependence between MSE2D and the discrete Fourier transform (DFT). To analyze this dependence, synthetic as well as biomedical images are analyzed. Our results reveal that i) the profile of MSE2D is sensitive to both the amplitude and phase of the DFT; ii) MSE2D could find applications in the biomedical field. This work brings valuable information for MSE2D interpretation and opens possibilities to study images from an entropy point of view through spatial scales
Genotyping-by-sequencing Approach Indicates Geographic Distance As The Main Factor Affecting Genetic Structure And Gene Flow In Brazilian Populations Of Grapholita Molesta (lepidoptera, Tortricidae).
The oriental fruit moth Grapholita molesta is one of the major pests of stone and pome fruit species in Brazil. Here, we applied 1226 SNPs obtained by genotyping-by-sequencing to test whether host species associations or other factors such as geographic distance structured populations of this pest. Populations from the main areas of occurrence of G. molesta were sampled principally from peach and apple orchards. Three main clusters were recovered by neighbor-joining analysis, all defined by geographic proximity between sampling localities. Overall genetic structure inferred by a nonhierarchical amova resulted in a significant ΦST value = 0.19109. Here, we demonstrate for the first time that SNPs gathered by genotyping-by-sequencing can be used to infer genetic structure of a pest insect in Brazil; moreover, our results indicate that those markers are very informative even over a restricted geographic scale. We also demonstrate that host plant association has little effect on genetic structure among Brazilian populations of G. molesta; on the other hand, reduced gene flow promoted by geographic isolation has a stronger impact on population differentiation.8476-48
Genotyping-by-sequencing approach indicates geographic distance as the main factor affecting genetic structure and gene flow in brazilian populations of grapholita molesta (lepidoptera, Tortricidae)
The oriental fruit moth Grapholita molesta is one of the major pests of stone and pome fruit species in Brazil. Here, we applied 1226 SNPs obtained by genotyping-by-sequencing to test whether host species associations or other factors such as geographic distance structured populations of this pest. Populations from the main areas of occurrence of G.molesta were sampled principally from peach and apple orchards. Three main clusters were recovered by neighbor-joining analysis, all defined by geographic proximity between sampling localities. Overall genetic structure inferred by a nonhierarchical amova resulted in a significant phi(ST) value=0.19109. Here, we demonstrate for the first time that SNPs gathered by genotyping-by-sequencing can be used to infer genetic structure of a pest insect in Brazil; moreover, our results indicate that those markers are very informative even over a restricted geographic scale. We also demonstrate that host plant association has little effect on genetic structure among Brazilian populations of G.molesta; on the other hand, reduced gene flow promoted by geographic isolation has a stronger impact on population differentiation85476485CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP578509/2008-3; 200942/2012-32011/00417-3Natural Sciences and Engineering Research Council of Canad
A visual pathway for skylight polarization processing in Drosophila
Many insects use patterns of polarized light in the sky to orient and navigate. Here, we functionally characterize neural circuitry in the fruit fly, Drosophila melanogaster, that conveys polarized light signals from the eye to the central complex, a brain region essential for the fly’s sense of direction. Neurons tuned to the angle of polarization of ultraviolet light are found throughout the anterior visual pathway, connecting the optic lobes with the central complex via the anterior optic tubercle and bulb, in a homologous organization to the ‘sky compass’ pathways described in other insects. We detail how a consistent, map-like organization of neural tunings in the peripheral visual system is transformed into a reduced representation suited to flexible processing in the central brain. This study identifies computational motifs of the transformation, enabling mechanistic comparisons of multisensory integration and central processing for navigation in the brains of insects
Manejo da resistência de Bonagota salubricola e Grapholita a inseticidas.
bitstream/item/73181/1/Folder-Maca-2012.pd
Metodologias para instalação de bioensaios para o monitoramento da resistência de bonagota salubricola e grapholita molesta a inseticidas.
Neste comunicado técnico, são apresentadas metodologias de bioensaios que podem ser empregadas para mensurar a suscetibilidade de Bonagota salubricola e Grapholita molesta a inseticidas, visando a disponibilizar técnicas para implementar um programa pró-ativo de manejo da resistência.bitstream/item/104060/1/Comunicado-Tecnico-152.pd
The frequency in Japanese of genetic variants of 22 proteins III. Phosphoglucomutase-1, phosphoglucomutase-2, 6-phosphogluconate dehydrogenase, adenylate kinase, and adenosine deaminase
Five enzyme systems, PGM 1 , PGM 2 , ADA, 6-PGD and AK, were examined by electrophoresis in over 4000 samples from Hiroshima and Nagasaki for the frequencies of common and rare variants. In the PGM 1 , system, the PGM 2 1 allele and PGM 7 1 ; allele were found in polymorphic proportions. I n addition, five kinds of slow variants and three types of fast variants of PGM 1 were detected. The PGM 3 NGS 1 1 allele was found in five individuals from Nagasaki, but was not observed in samples from Hiroshima. There were no variants of PGM 2 . Three kinds of fast variants of 6-PGD were detected. NO variation in AK was observed. There were no rare variants of ADA. The 6-PGD c allele had a frequency of 0.084 in Hiroshima, and 0.093 in Nagasaki, and the ADA 2 allele frequencies of 0.025 in Hiroshima and 0.032 in Nagasaki.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65524/1/j.1469-1809.1977.tb01912.x.pd
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