Global genomic methylation related to the degree of parasitism in cattle.

The objective of the present study was to characterize a herd of 72 ½ Angus × ½ Nellore heifers, identify the resistant, resilient and susceptible animals to parasites, relate the overall DNA methylation of these animals with the degree of parasitism, evaluated by the egg count per gram of feces (EPG), Haematobia irritans count (horn fly) and Rhipicephalus microplus count (bovine tick). The experiment was carried out in a completely randomized design, containing 72 treatments, with each animal considered a treatment, and 11 repetitions, with each collection within a year considered a repetition. The data obtained from the counts of the evaluated parasites were subjected to statistical analysis using the SISVAR program, to classify heifers according to the degree of parasitism in low (resistant), intermediary (resilient) and high (susceptible) parasite load for infection by nematodes, infestation by ticks and flies. Addition the animals in these three groups, by hierarchical grouping using the GENES program, heifers were classified as to the degree of parasitism by the three parasites along with the DNA methylation content of the animals in each group. A negative relationship was observed between resistance and methylated DNA content in both classifications, with the resistant, resilient, and susceptible animals showing the highest, intermediate, and lowest methylated DNA quantifications, respectively. Thus, the methodologies used herein enabled the classification of 72 heifers according to the degree of collective infection by gastrointestinal nematodes and infestation by ticks and horn flies, thereby establishing a link between the degree of parasitic resistance in cattle and the global methylated DNA quantification.

Development of Tenebrio molitor (Coleoptera: Tenebrionidae) on Poultry Litter-Based Diets: Effect on Chemical Composition of Larvae.

In order to investigate a low-cost and sustainable food source, the present study evaluated the use of poultry litter for rearing Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae). The experiment was performed with five diets containing increasing levels of poultry litter (0, 25, 50, 75, and 100%) replacing the control diet and five replicates with 50 larvae per sample unit. Larval growth and development were evaluated and the chemical compositions of diet and T. molitor larvae were determined. Larval development and reproduction efficiency of T. molitor were similar in all treatments. The sole use of poultry litter to feed T. molitor reduced the crude protein of flour by only 8%. Including 50% or more poultry litter in the standard diet is the best-suited formulation for larvae production and incorporation of minerals in the larvae. Mealworm can be grown successfully on diets composed by poultry litter, the diet did not affect survival, growth, and development; however, studies spanning several insect generations should be performed to determine the effects of diet composition on adult fecundity. The knowledge acquired using poultry litter to feed T. molitor will be useful to carry out new research, in addition to evidencing the possibility of low-cost mass rearing of these larvae.

Esterase activity in homogenates of Helicoverpa armigera (Hubner) (Lepidoptera: noctuidae) exposed to different insecticides and the behavioral effect / Atividade esterase em homogenatos de helicoverpa armigera (hubner) (lepidoptera: noctuidae) expostos a diferentes inseticidas e o efeito comportamental

The toxicity of some insecticides to Helicoverpa armigera was studied through sublethal effects, evaluating the enzymatic activity of esterase and the behavioral response. The commercial formulation of insecticides selected were chlorpyrifos, spinosad, indoxacarb, chlorantraniliprole, lambda-cyhalothrinand Bacillus thuringiensis, corresponding the most used by farmers to control of H. armigera. To determine the esterase activity, the larvae were fed with soybean leaf discs dipped in insecticide solution using the lethal concentration (LC50). For the behavioral response, filter paper were immersed in three concentrations of insecticides (LC50, LC95 and recommend dose.), then the behavior of the larvae observed in Videomex-One. The results for the enzymatic activity showed an increase in the activity of the esterase, with variation along the treatments and the time of exposure of the insects to the insecticides. With exception of spinosad, other insecticides showed an increase in EST-α activity, 6 and 24 hours after contact of caterpillars with insecticide.Different behavioral patterns of walking (walking distance, walking speed and resting time) were observed for H. armigera exposed to different insecticides. H. armigera exposed to chlorpyrifos, lambda-cyhalothrin and B. thuringiensis insecticides show greater esterase activity. Regarding walking behavior, the results confirms enzymatic activity, where H. armigera have behavioral alteration after exposure to insecticide.

A toxicidade de alguns inseticidas a Helicoverpa armigera foi estudada através de efeitos subletais, avaliando a atividade enzimática da esterase e a resposta comportamental. A formulação comercial dos inseticidas selecionados foram clorpirifos, espinosad, indoxacarb, clorantraniliprole, lambda-cialotrina eBacillus thuringiensis utilizados pelos agricultores para controle de H. armigera. Para determinar a atividade da esterase, as larvas foram alimentadas com discos de folha de soja mergulhados em solução de inseticida usando a concentração letal (CL50). Para os testes de características comportamentais, papel filtro foi imerso em três concentrações de inseticidas (CL50, CL95 e dose recomendada), posteriormente o comportamento das larvas foi observado em Videomex-One. Os resultados para a atividade enzimática mostraram aumento da atividade daesterase, com variação ao longo dos tratamentos e do tempo de exposição dos insetos aos inseticidas. Com exceção do spinosad, outros inseticidas mostraram um aumento na atividade EST-α, 6 e 24 horas após o contato das lagartas com inseticida. Diferentes padrões comportamentais de caminhada (distância percorrida, velocidade de caminhada e tempo de repouso) para H. armigera exposto a diferentes classes de inseticidas. H. armigera exposta aos inseticidas clorpirifos, lambda-cialotrina e B. thuringiensis mostraram maior atividade da esterase. Em relação ao comportamento ambulante, os resultados confirmam a atividade enzimática, onde H. armigera teve alteração comportamental após exposição ao inseticida.

Lepidopteran pests associated with the soybean cultivars phenology / Lepidopteros-praga associados com estágios fenológicos de cultivares de soja

Lepidopteran pests are one of the major constraints to the soybean production potential, whose defoliating caterpillars can occur throughout the crop cycle causing serious damage. Therefore, the objective was to study the population fluctuation of lepidopteran pests and the association of species with the growth stages of soybean cultivars in the Cerrado of Piaui State, Brazil, in order to obtain data to support integrated pest management in the crop. The experiments had as a source of variation thirteen cultivars with fourteen evaluations. The design used was completely randomized in split plots being the cultivars plots and subplots the cultivars phenological stages. The monitoring was conducted by shake-cloth method at random points. Weekly samplings were performed. Generally, species of lepidopteran pests occurred in all soybean phenological stages, especially Chrysodeixis includens and Anticarsia gemmatalis that were present from the beginning to the end of the crop.

Lepidópteros-praga estão entre os principais entraves ao potencial de produção de soja, cujas lagartas desfolhadoras podem ocorrer ao longo do ciclo da cultura, causando sérios danos. Portanto, o objetivo foi estudar a flutuação populacional de lepidópteros-praga e a associação dessas espécies com os estádios de crescimento de cultivares de soja no Cerrado do Estado de Piauí, a fim de obter dados para apoiar o manejo integrado de pragas na cultura. Os experimentos tiveram como fonte de variação treze cultivares com catorze avaliações. O delineamento utilizado foi inteiramente casualizado em parcelas subdivididas, sendo os cultivares as parcelas e as subparcelas os estádios fenológicos dos cultivares. O monitoramento foi realizado por meio do método de pano-de-batida em pontos aleatórios. Foram realizadas amostragens semanais. Em geral, espécies de lepidópteros-praga ocorreram em todos os estádios fenológicos da cultura da soja, especialmente Chrysodeixis includens e Anticarsia gemmatalis que estavam presentes desde o início até o final da cultura.

Rotary peeling yield of Schizolobium amazonicum (Leguminosae - Caesalpinioideae) / Rendimento em laminação da madeira de paricá (Schizolobium amazonicum, Leguminosae - Caesalpinioideae)

The tropical tree Schizolobium amazonicum is native from the Amazonian forest, naturally occurring in Brazil, Peru and Colombia. This work aimed to study the veneer yield made from this species. For this purpose, 50 logs from S. amazonicum were rotary peeled in a plywood industry installed in Brazilian Amazon region. The results indicated that S. amazonicum had a peeling yield similar or even higher than those usually obtained for species traditionally used for this purpose in Brazil, like those of Pinus and Eucalyptus. It was also observed that the dendrometric parameters of the log can be used to estimate the peeling yield in this species.

O paricá (Schizolobium amazonicum) é uma espécie nativa da floresta amazônica, que ocorre naturalmente no Brasil, Peru e Colômbia. O objetivo do presente trabalho foi avaliar o rendimento em laminação da madeira de paricá. Para isso foram avaliadas toras da espécie em uma fábrica de compensado instalada na região Amazônica brasileira. Os resultados indicaram que o paricá apresenta um elevado rendimento em laminação, sendo similar ou em alguns casos até superior a espécies tradicionalmente utilizadas para esta finalidade no Brasil, como as dos gêneros Pinus e Eucalyptus. Observou-se ainda que o rendimento em laminação da espécie pode ser estimado por meio dos parâmetros dendrométricos das toras.