Bitter lupins (Lupinus spp.) are not used as a protein source because of their toxicity. However, they may have alternative uses as potential sources of natural insecticides. Quinolizidine alkaloids (QA) of three Mexican Lupinus species (Fabaceae): L. montanus (HBK), L. stipulatus (Agardh) and L. aschenbornii (Schauer), were analyzed by capillary Gas Chromatography-Mass Spectrometry. Sparteine was found in high amounts in both L. montanus and L. aschenbornii while the major alkaloids in L. stipulatus extract were aphylline and an epiaphylline-like compound. Alkaloid extracts were tested for their insecticidal activity using larvae of the Fall Armyworm, Spodoptera frugiperda (Smith); (Lepidoptera, Noctuidae) as a model pest. We compared LD 50 values and mean weight of caterpillars fed with alkaloid extracts of the three species studied with those of sparteine, a widespread QA found in various lupin species. Extracts of L. montanus and L. aschenbornii were found to be as effective as sparteine and extracts L. stipulatus were found to be the most toxic against the larvae of S. frugiperda. This suggests that the various QA act differently on caterpillars, and could be used to control Spodoptera populations.

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The biological activity of extracts from Trichilia americana (Sesse and Mocino) T.D. Penn. (rind), Carica papaya L., Jatropha curcas L., Ricinus communis L., and Lupinus campestris Schldl. & Cham. (seeds), at 1% and 5%, were evaluated on neonates of Copitarsia decolora Guenée in ingestion bioassays. The plants that caused the highest percentage of larval mortality were T. americana at 1% and 5%, and Carica papaya at 5% with 98% and 100% and 100%, respectively. Trichilia americana was the plant with higher toxicological properties against C. decolora. Extracts in hexane, ethyl acetate, acetone, and methanol from T. americana were then evaluated at 10, 100, 300, and 1,000 ppm also in ingestion bioassays against C. decolora. Extracts of ethyl acetate and acetone at 1,000 ppm recorded the highest percentages of larval mortality of C. decolora (90% and 55%, respectively). In addition to larval mortality, feeding on T. americana extract also decreased mean larval weight, prolonged duration of the larval stage, resulted in malformed pupae and adults, and affected adult fertility and fecundity. Finally, these extracts were evaluated in a toxicity model, for which the crustacean Artemia salina Leach was used. The ethyl acetate, acetone, and hexane extracts showed no toxicity to A. salina, while the methanol extract caused 30% mortality, which is considered to be slightly toxic. Based on the results obtained, T. americana is a species with insecticidal and insectistatic activity against C. decolora and can be considered as a potential insecticide for the management of this or other insect pests.

Este trabalho teve como objetivo avaliar a produtividade e adaptação das variedades de mandioca ARN, BRS 399, BRS 400, BRS 401 e Cacau na região norte do estado do Tocantins em sistema irrigado. O ensaio foi conduzido na área experimental do Instituto Federal do Tocantins (IFTO), campus Colinas do Tocantins. O delineamento utilizado foi em blocos casualizados, sendo os tratamentos as variedades de mandiocas mencionadas, com quatro repetições. Cada repetição apresentou quatro linhas de dez plantas, sendo que a parcela experimental útil foi composta pelas duas linhas centrais, na qual avaliou-se as cinco plantas centrais de cada linha útil. O manejo de irrigação adotado foi o de fitas gotejadoras. Foram realizadas três adubações e a avaliação ocorreu nove meses após o plantio. As variáveis avaliadas foram: altura da planta e da primeira bifurcação, massa da parte aérea, massa das raízes tuberosas (produtividade das raízes), índice de colheita, tempo de cocção, teor de amido e rendimento de farinha. Os resultados evidenciaram a existência de diferenças significativas, entre as cinco variedades testadas, para os parâmetros altura da planta e da primeira ramificação, massa da parte aérea, produtividade de raízes e tempo de cocção. Todas as variedades obtiveram produtividade satisfatória, sendo que a BRS 401, BRS 400 e a BRS 399 destacaram-se por apresentar 61,26, 52,34 e 49,70 t/ha, respectivamente. As variedades Cacau, ARN e BRS 401 apresentaram os menores tempo de cocção, 16, 17 e 18,5 minutos, respectivamente. O genótipo BRS 401 apresentou maior altura de planta, e da primeira ramificação, maiores produtividades de raiz (61,26 t/ha) e da parte aérea (30,97 t/ha). De modo geral, todas as variedades apresentaram resultados satisfatórios e podem ser recomendadas para o plantio na região norte do Tocantins.

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