Genetic divergence among tomato leafminer populations based on AFLP analysis.

The objective of this work was to determine the genetic differences among eight Brazilian populations of the tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), from the states of Espírito Santo (Santa Tereza), Goiás (Goianápolis), Minas Gerais (Uberlândia and Viçosa), Pernambuco (Camocim de São Félix), Rio de Janeiro (São João da Barra) and São Paulo (Paulínia and Sumaré), using the amplified fragment length polymorphism (AFLP) technique. Fifteen combinations of EcoRI and MseI primers were used to assess divergence among populations. The data were analyzed using unweighted pair-group method, based on arithmetic averages (UPGMA) bootstrap analysis and principal coordinate analysis. Using a multilocus approach, these populations were divided in two groups, based on genetic fingerprints. Populations from Goianápolis, Santa Tereza, and Viçosa formed one group. Populations from Camocim de São Félix, Paulínia, São João da Barra, Sumaré, and Uberlândia fitted in the second group. These results were congruent with differences in susceptibility of this insect to insecticides, previously identified by other authors

Assessing the impact of climate change on the worldwide distribution of Dalbulus maidis (DeLong) using MaxEnt

For the first time, a model was applied at the global scale in order to investigate the effects of climate change on Dalbulus maidis. D. maidis is the main vector of three plant pathogens of maize crops and has been reported as one of the most important maize pests in Latin America. We modeled the effects of climate change on this pest using three Global Climate Models under two Representative Concentration Pathways (RCPs) using the MaxEnt software. Overall, climate change will lead to a decrease in the suitable areas for D. maidis. In South America, climate change will decrease the areas that are suitable for the pest, especially in Brazil. However, Argentina, Chile, Colombia, Ecuador, Peru, and Venezuela will have small areas that are highly suitable for the corn leafhopper. Outside of the pest’s range, Ethiopia, Kenya, Rwanda, Burundi, and South Africa also should be concerned about the risk of corn leafhopper invasions in the future since they are projected to have highly suitable conditions for this insect in some areas. This study will allow the relevant countries to increase their quarantine measures and guide researchers to develop new Z. mays varieties that are resistant or tolerant to D. maidis. In addition, the maize‐stunting pathogens for the areas are highlighted in this modeling

Age and Environment Influences on Mouse Prion Disease Progression: Behavioral Changes and Morphometry and Stereology of Hippocampal Astrocytes

Because enriched environment (EE) and exercise increase and aging decreases immune response, we hypothesized that environmental enrichment and aging will, respectively, delay and increase prion disease progression. Mice dorsal striatum received bilateral stereotaxic intracerebral injections of normal or ME7 prion infected mouse brain homogenates. After behavior analysis, animals were euthanized and their brains processed for astrocyte GFAP immunolabeling. Our analysis related to the environmental influence are limited to young adult mice, whereas age influence refers to aged mice raised on standard cages. Burrowing activity began to reduce in ME7-SE two weeks before ME7-EE, while no changes were apparent in ME7 aged mice (ME7-A). Object placement recognition was impaired in ME7-SE, NBH-A, and ME7-A but normal in all other groups. Object identity recognition was impaired in ME7-A. Cluster analysis revealed two morphological families of astrocytes in NBH-SE animals, three in NBH-A and ME7-A, and four in NBH-EE, ME7-SE, and ME7-EE. As compared with control groups, astrocytes from DG and CA3 prion-diseased animals show significant numerical and morphological differences and environmental enrichment did not reverse these changes but induced different morphological changes in GFAP+ hippocampal astroglia. We suggest that environmental enrichment and aging delayed hippocampal-dependent behavioral and neuropathological signs of disease progression

Seletividade de inseticidas a Podisus nigrispinus predador de Ascia monuste orseis

The objective of this research was to evaluate the selectivity of Carbaryl, Deltamethrin, Methyl Parathion, Permethrin and Thrichorfon to the predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) testing dosages of these insecticides which caused 90% mortality of 4th and 5th instars Ascia monuste orseis (Godart) (Lepidoptera: Pieridae) caterpillars. The most selective insecticide to P. nigrispinus was Permethrin, followed by Deltamethrin and Methil Parathion. Nymphs of 5th instar of this predador were more tolerant to Thrichorfon than adults and nymphs of 3th instar. Females of P. nigrispinus were more tolerant to Methil Parathion than males.Nesta pesquisa estudou-se a seletividade dos inseticidas Carbaril, Deltametrina, Paratiom Metílico, Permetrina e Triclorfom ao predador Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) em dosagens que causaram 90% de mortalidade em lagartas de 4o e 5o ínstares de curuquerê-da-couve (Ascia monuste orseis Godart) (Lepidoptera: Pieridae). O inseticida mais seletivo ao curuquerê-da-couve em relação ao percevejo predador P. nigrispinus foi a Permetrina, seguida da Deltametrina e Paratiom Metílico. As ninfas de 5o ínstar do percevejo predador P. nigrispinus foram mais tolerantes ao inseticida Triclorfom que os adultos e ninfas de 3o ínstar. As fêmeas do predador P. nigrispinus foram mais tolerantes que os machos ao Paratiom Metílico

Tick and host derived compounds detected in the cement complex substance

Ticks are obligate hematophagous arthropods and vectors of pathogens affecting human and animal health worldwide. Cement is a complex protein polymerization substance secreted by ticks with antimicrobial properties and a possible role in host attachment, sealing the feeding lesion, facilitating feeding and pathogen transmission, and protection from host immune and inflammatory responses. The biochemical properties of tick cement during feeding have not been fully characterized. In this study, we characterized the proteome of Rhipicephalus microplus salivary glands (sialome) and cement (cementome) together with their physicochemical properties at different adult female parasitic stages. The results showed the combination of tick and host derived proteins and other biomolecules such as a-Gal in cement composition, which varied during the feeding process. We propose that these compounds may synergize in cement formation, solidification and maintenance to facilitate attachment, feeding, interference with host immune response and detachment. These results advanced our knowledge of the complex tick cement composition and suggested that tick and host derived compounds modulate cement properties throughout tick feeding