RESUMO Investigou-se o potencial inseticida de óleos vegetais de plantas ocorrentes na Amazônia Sul Ocidental sobre Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae). Inicialmente, foram realizados bioensaios utilizando-se óleos puros (sem diluições), oriundos de 11 espécies vegetais. A eficiência dos óleos foi avaliada para ovos e para lagartas de terceiro ínstar de S. frugiperda. Os óleos de Copaifera sp. (Leguminosae), Orbignya phalerata (Arecaceae) e Carapa guianensis (Meliaceae) apresentaram elevada eficiência para as lagartas de S. frugiperda, sendo, portanto utilizados nos bioensaios subsequentes de concentração-resposta. As concentrações de cada óleo, utilizadas nestes testes de concentração-mortalidade, foram estabelecidas por meio de testes preliminares. Estabeleceram-se as maiores concentrações dos óleos em que não ocorresse morte de insetos e as menores concentrações em que ocorresse a maior mortalidade. Com base nos dados obtidos, foram estabelecidos os intervalos definitivos. O delineamento inteiramente casualizado foi adotado em ambos os bioensaios. As CL50 variaram de 7,50 a 60,84% (v/v) entre os óleos. O óleo de Copaifera sp. apresentou maior toxicidade para as lagartas, sendo 6,84 vezes mais tóxico que o óleo de O. phalerata e 8,11 vezes mais tóxico que o óleo de Carapa guianensis. Em geral, os óleos de Copaifera sp., O. phalerata e Carapa guianensis são eficazes no controle de lagartas de S. frugiperda, sob condições de laboratório, destacando-se como candidatos a uso nos programas de manejo integrado das pragas do milho.

ABSTRACT The potential insecticidal of oils from southwestern Amazon plants against Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) was investigated. Initial bioassays were performed with undiluted oils from 11 plant species. The efficacy of the oils was evaluated against eggs and third -instar caterpillars of S. frugiperda. The oils of Copaifera sp. (Leguminosae), Orbignya phalerata (Arecaceae), and Carapa guianensis (Meliaceae) displayed a high efficacy against the caterpillars and were used in subsequent concentration-response bioassays, at concentrations established through preliminary tests. The highest nonlethal concentrations of oils and the lowest lethal concentrations were calculated. A completely randomized design was adopted in both bioassays. The LC50 of the oils varied from 7.50 to 60.84% (v/v). Copaifera sp. oil had the highest toxicity and was 6.84-fold more toxic than O. phalerata oil and 8.11-fold more toxic than Carapa guianensis oil. In general, oils from Copaifera sp., O. phalerata, and Carapa guianensis were effective in controlling S. frugiperda caterpillars under laboratory conditions, and are good candidates for use in integrated management programs of corn pests.

This study aimed to screen plant species from the Amazon region for the potential to be used in the integrated management of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). For this purpose, the efficiency of the hydroalcoholic extracts of 15 plant species from the Amazon region was evaluated. The extracts were obtained from plant leaves, bark, or vines. The efficiency of the extracts (30 mg-mL-1) was evaluated on eggs and third instar larvae of S. frugiperda. A range of reactions of the fall armyworm to the hydroalcoholic extracts was observed. The extract obtainedfrom the bark of Calycophyllum spruceanum (Benth.) Hook. f. ex K. Schum. presented the highest efficiency against the eggs, whereas the extract obtained from the leaves of Bauhinia forficata Link was most efficient against the larvae. These findings are essential for the management offall armyworms because the deleterious effects in the initial stages of S. frugiperda development significantly reduce maize production. In conclusion, the extracts of C. spruceanum and B. forficata were more efficient for eggs and larvae of the fall armyworm, respectively.

Esta investigación tiene el objetivo de hacer una selección de especies vegetales que son propias de la región Amazónica con potencial de uso en el manejo integrado de la oruga militar tardía Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Para tal, fue evaluado la eficiencia de extractos hidroalcohólicos de 15 especies vegetales que se son de la región. Los extractos fueron producidos a partir de las hojas, o de la cáscara, o de liana de las plantas. La eficiencia de los extractos (30 mg.mL-1) fue evaluada sobre huevos y larvas de 3° instar de S. frugiperda. Se constató una variación de respuesta de la oruga militar tardía entre los extractos hidroalcohólicos. El extracto de la cáscara de Calycophyllum spruceanum (Benth.) Hook. f. ex K. Schum. presentó mayor eficiencia en los huevos, y el extracto de las hojas de Bauhinia forficata Link presentó mayor eficiencia en las larvas. Estos resultados son fundamentales para el manejo de la oruga militar tardía, toda vez que, los efectos nocivos reducen las pérdidas en la producción de maíz en las primeras fases del desarrollo del S. frugiperda. Se concluye que los extractos de C. spruceanum y B. forficata fueron los más eficientes para los huevos y larvas de la oruga militar tardía.

Este artigo descreve o isolamento dos triterpenos lupeol, taraxerol, lupen-3-ona e esqualeno obtido do extrato diclorometânico das folhas da espécie Minquartia guianensis Aubl., pertencente à família Olacaceae. Estes terpenóides foram isolados através de técnicas cromatográficas e identificados utilizando Ressonância Magnética Nuclear (RMN) de ¹H e de 13C. Na literatura disponível, este é o primeiro relato destes triterpenos em M. guianensis.

This article describes the isolation of the triterpenes lupeol, taraxerol, lupen-3-one and squalene from the dichloromethane extract of the leaves of Minquartia guianensis Aubl. belonging to the Olacaceae family. These terpenoids were isolated through chromatographic techniques and identified using ¹H and 13C Nuclear Magnetic Resonance (NMR). At the best of our knowledge, this is the first report of these triterpenes in M. guianensis.

Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas), of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin), were determined through analyses of NMR 1D (¹H and 13C) and NMR 2D (gHSQC and gHMBC). These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae). The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active.