Antonia Railda Roel

Toxic activity of organic extracts from Trichilia pallida Swartz (Meliaceae) against Spodoptera frugiperda (J. E. Smith)

The objective of this research was to evaluate the toxic activity of different concentrations (weight/volume) of organic extracts (non-aqueous) of leaves and twigs of Trichilia pallida Swartz on Spodoptera frugiperda (J. E. Smith) under laboratory conditions. Pieces of corn leaves were dipped in acetone solutions of T. pallida extracts at concentrations ranging from 0.008 to 1%. Larval mortality of S. frugiperda was evaluated during 10 days and acetone extracts of leaves and twigs and methanol extracts of twigs showed greater activity than methanol extract of leaves. Crude acetone extract was partitioned with hexane and ethyl acetate and evaluated by using the same methodology. Ethyl acetate fraction was more effective than hexane. Comparing the four solvents, the highest toxic activity of the extracts was obtained using acetone, followed by methanol, ethyl acetate and hexane.

Mice and larvae tracking using a particle filter with an auto-adjustable observation model

This paper proposes a novel way to combine different observation models in a particle filter framework. This, so called, auto-adjustable observation model, enhance the particle filter accuracy when the tracked objects overlap without infringing a great runtime penalty to the whole tracking system. The approach has been tested under two important real world situations related to animal behavior: mice and larvae tracking. The proposal was compared to some state-of-art approaches and the results show, under the datasets tested, that a good trade-off between accuracy and runtime can be achieved using an auto-adjustable observation model.

The effect of sub-lethal doses of Azadirachta indica (Meliaceae) oil on the midgut of Spodoptera frugiperda (Lepidoptera, Noctuidae)

The fall armyworm, Spodoptera frugiperda, is one of the major field pests for maize production. It is mainly controlled by means of synthetic, and more recently by resistant cultivar of maize expressing Bt toxins. The neem tree, Azadirachta indica, is a plant that can potentially control insects with the advantage of being food and environmental safe. The aim of this study was to assess the effect of neem oil on the development and survival of S. frugiperda caterpillars by assessing histological alterations caused on their midgut. Newly hatched caterpillars were submitted to three neem oil concentrations: 0.006; 0.05; 0.4%, which were added to their artificial diet. Ten 3rd instar caterpillars, taken from each treatment, were submitted to histological analysis. The alimentary canals from the specimens were fixed in Baker for 12 hours, desiccated and diaphanized in alcohol/xylol (1:1) and xylol. After placing the samples in paraffin, they were sliced in 8 µm sections and stained with hematoxylin-eosin stain. The neem oil added to the diet of S. frugiperda caused total mortality at dose of 0.4% whilst still in the first instars, prolonged the larval and pupal stages, and reduced the pupal weight. Histo-physiological alterations such as degeneration of the epithelial lining of the midgut and in the peritrophic matrix were found at all concentrations of neem oil.

Atividade larvicida do óleo de Anacardium humile Saint Hill sobre Aedes aegypti (Linnaeus, 1762) (Diptera, Culicidae)

The objective of this study was to evaluate the potential of Anacardium humile (monkey nuts) against Aedes aegypti larvae. Hexane, ethanol and aqueous extracts and oil from leaves were obtained from plant material collected from the Brazilian savanna. These were tested at concentrations of 1%, 0.5%, 0.25%, 0.125%, 0.05% and 0.0125%, diluted in 1% dimethyl sulfoxide. The dead larvae were counted 24 hours later. The Probit analysis method was used to obtain the LC(50) and the respective confidence intervals. The conclusion was that only the oil extracted from Anacardium humile leaves caused 100% mortality among fourth-instar Aedes aegypti larvae, using concentrations of up to 0.125%. This seems to indicate that the active ingredients are present in the most apolar phase. This indicates that this plant has potential use as a larvicide against Aedes aegypti. However, new tests should be carried out using other plant organs, as well as using other methods and solvents for the extraction.

Efeito residual do extrato acetato de etila de Trichilia pallida Swartz (Meliaceae) para lagartas de diferentes idades de Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae)

Botanical pesticides have limited persistence in field conditions because are degraded by temperature, ultraviolet light and other environmental factors. Corn plants cultivated in greenhouse were sprayed with ethyl acetate extract of Trichilia pallida at the concentration of 2%, and their leaves were offered to Spodoptera frugiperda larvae in order to evaluate the residual effect of the extract. The larval feeding began at 1, 3 and 7 days after the treatment with the extract. Two groups of larvae were evaluated: neonate and 10-day old ones. The leaves were daily replaced and after 10 days the mortality, the head capsules and the weight of larvae were evaluated. Independently of the residue age, all treatments affected larval survivorship and delayed larval development, but these effects were more pronounced for larvae fed one day treated leaves. The extract was more effective against neonate larvae than to 10 days old day larvae.

Eficiência de produtos vegetais no controle da lagarta-do-cartucho-do-milho Spodoptera frugiperda (J.E.Smith, 1797) (Lepidoptera: Noctuidae)

O presente trabalho teve por objetivo avaliar a eficiencia de produtos vegetais no controle de Spodoptera frugiperda (J.E.Smith, 1797) na cultura do milho. Os experimentos foram instalados, nos anos de 2002 e 2004, com a pulverizacao dos produtos vegetais em cinco tratamentos, e quatro repeticoes. No ano de 2002, os produtos testados foram: Azadirachta indica A. Juss. (extrato aquoso 2%), e oleo a 1%; Melia azedarach L. (extrato aquoso 2%); Quassia amara L. (extrato aquoso 2%); oleo de nim, Azadirachta indica 1 e 2%. No ano de 2004, os produtos testados foram: A. indica (extrato aquoso 5%), e oleo a 2%, M. azedarach (extrato aquoso 5%), Trichilia pallida Sw. (extrato aquoso 5%). As avaliacoes, porcentagem de infestacao da lagarta-do-cartucho por parcela, foram efetuadas aos tres, sete e dez dias apos a pulverizacao dos extratos. Conclui-se que extratos aquosos das plantas A. indica 2%, T.pallida 5%, Q. amara 2% e M. azedarach 2% e 5% e oleo de A. indica 1% e 2% com adicao de tenso ativo nao ionico, nao possuem eficiencia necessaria como unico metodo de controle da largarta-do-cartucho S. frugiperda em condicoes de campo. Os produtos comecam a afetar o desenvolvimento da lagarta apos alguns dias da ingestao das folhas pulverizadas, observado na avaliacao efetuada aos sete dias apos a aplicacao dos extratos.

Levantamento do potencial de comercialização de produtos orgânicos para o estado de Mato Grosso do Sul

Evaluation the potential market in Campo Grande for organic products, it was concluded that most of the interviewed women declared to know organic product is, although only a half part of them actually knew its meaning. Around 52% of the evaluated group would spend higher values to acquire organic products, and 66.23% were willing in going to a specific market place. Almost the entirely interviewed women (939.35%) would choose organic products after an explanation about their benefits.La evaluacion del potencial de mercado consumidor de productos organicos en Campo Grande, MS, he llegado a la conclusion de que la mayoria de las mujeres entrevistadas afirmaran conocer el producto ecologico, sin embargo, solo aproximadamente la mitad sabe realmente su significado. Aproximadamente el 52% de ellas pagarian mas caro por ese producto y estarian dispuestas a ir asta tiendas especificas para su comercializacion (63,23%). Despues de una aclaracion sobre los beneficios del producto ecologico, casi la totalidad (99,35%) optarian por estos productos.

BioLeaf: A professional mobile application to measure foliar damage caused by insect herbivory

Abstract Soybean is one of the ten greatest crops in the world, answering for billion-dollar businesses every year. This crop suffers from insect herbivory that costs millions from producers. Hence, constant monitoring of the crop foliar damage is necessary to guide the application of insecticides. However, current methods to measure foliar damage are expensive and dependent on laboratory facilities, in some cases, depending on complex devices. To cope with these shortcomings, we introduce an image processing methodology to measure the foliar damage in soybean leaves. We developed a non-destructive imaging method based on two techniques, Otsu segmentation and Bezier curves, to estimate the foliar loss in leaves with or without border damage. We instantiate our methodology in a mobile application named BioLeaf, which is freely distributed for smartphone users. We experimented with real-world leaves collected from a soybean crop in Brazil. Our results demonstrated that BioLeaf achieves foliar damage quantification with precision comparable to that of human specialists. With these results, our proposal might assist soybean producers, reducing the time to measure foliar damage, reducing analytical costs, and defining a commodity application that is applicable not only to soy, but also to different crops such as cotton, bean, potato, coffee, and vegetables.

Melhoramento genético de erva-mate nativa do Estado de Mato Grosso do Sul

This study aimed at the genetic evaluation of growth of the best erva-mate progenies derived from native individual selected at the Indian reserve in Caarapo, Mato Grosso do Sul State. Experimental design of the progeny test was randomized blocks with 30 treatments, 5 replicates and 10 plants per plot in single rows at 3 x 2 m spacing. Fourteen months old, progenies were evaluated for height and diameter of seedlings. Restrict individual heritability were of medium and high magnitudes (0.15 and 0.28) for height and diameter respectively. Estimated genetic gains with individual selection ranged from 5.23 to 8.51 cm for height and from 2.08 to 3.15 mm for diameter. Predicted genetic values with sexual and asexual propagation indicate better gain potentials for the latter. Evaluation overlapping generations indicate that individuals from current generation tend to be better than the ones from the preceding generation.

First record of Peckia (Sarcodexia) lambens (Wiedemann, 1830) (Diptera: Sarcophagidae) parasitizing Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) in Brazil

Arq. Inst. Biol., v.84, 1-4, e0302016, 2017 RESUMO: Coletas de larvas de Spodoptera frugiperda (Smith, 1797) (Lepidoptera: |Noctuidae) realizadas no campo em três localidades da cidade de Campo Grande, Mato Grosso do Sul, Brasil, entre outubro de 2012 e março de 2014, registraram a presença de três espécies de Diptera como parasitoide de S. frugiperda: duas espécies de Tachinidae, Archytas incertus (Macquart, 1851) e Winthemia trinitatis Thompson, 1963, e uma espécie de Sarcophagidae, Peckia (Sarcodexia) lambens (Wiedemann 1830), sendo esta identificada pela primeira vez no país como parasitoide larval de S. frugiperda.