Toxicidade de extratos de nim (Azadirachta indica) ao ácaro-vermelho-do-cafeeiro Oligonychus ilicis

Abstract

Resumo -O objetivo deste trabalho foi estudar a toxicidade aguda e crônica de extratos de óleo de torta, de sementes e de folhas de Azadirachta indica A. Juss (nim) a fêmeas do ácaro-vermelho-do-cafeeiro Oligonychus ilicis (McGregor) (Acari: Tetranychidae). A mortalidade e a taxa instantânea de crescimento populacional de fêmeas adultas desse ácaro foram avaliadas em discos de folhas de cafeeiro com 3,5 cm de diâmetro, impregnados com resíduo seco dos extratos de nim e flutuando em água. As concentrações dos extratos de óleo de torta, sementes e folhas de nim que mataram 50% e 99% dos indivíduos de O. ilicis, após 72 horas de exposição, foram de 0,02, 15,9 e 121,4 mg/mL e de 10,9, 520,9 e 277,4 mg/mL, respectivamente. A taxa instantânea de crescimento populacional de O. ilicis diminuiu, linearmente, com o aumento da concentração dos extratos de óleo de torta, sementes e folhas de nim até 0,075, 15 e 144 mg/mL, respectivamente, a partir das quais as populações desse ácaro foram extintas.Termos para indexação: pesticida natural, praga do café, inseticida botânico. Toxicity of neem extracts (Azadirachta indica) to the coffee red mite Oligonychus ilicisAbstract -The objective of this work was to study the toxicity of extracts of oil cake, seeds and leaves of Azadirachta indica A. Juss (neem) to the coffee red mite Oligonychus ilicis (McGregor) (Acari: Tetranychidae). Concentration-mortality and instantaneous rate of populational growth were determined for adult females of the red mite on disks of coffee with 3.5 cm diameter, floating on water and impregnated with dry residues of the neem extracts. Concentrations of these extracts which caused 50% mortality of the individuals of O. ilicis were 0.02, 15.9 and 121.4 mg/mL; while 99% mortality of this mite was reached with 10.9, 520.9 and 277.4 mg/mL for oil cake, seeds and leaves extracts, respectively. The instantaneous rate of populational growth of O. ilicis dropped as the extract doses increased up to 0.075, 15 and 144 mg/mL for oil cake, seeds and leaves extracts, respectively.

Deleterious Activity of Natural Products on Postures of Spodoptera frugiperda (Lepidoptera: Noctuidae) and Diatraea saccharalis (Lepidoptera: Pyralidae)

“…On the other hand, the emergence of adults of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) or Trichogramma exiguum Pinto and Platner (Hymenoptera: Trichogrammatidae) from eggs of Plutella xylostella L. (Lepidoptera: Plutellidae) after application of neem, pyroligneous extract or a mixture of these products with synthetic insecticides (Thuler et al, 2008) and that of Telenomus remus Nixon (Hymenoptera: Scelionidae) parasitizing eggs of S. frugiperda treated with extracts of Asteraceae (Tavares et al, 2009) was lower, suggesting that the use of these products might diminish the emergence of natural enemies from parasitized egg masses. Other botanic products, such as neem, astilbin, and Asteraceae extracts caused mortality of pests [Oligonychus ilicis McGregor (Acari: Tetranychidae)] (Mourão et al, 2004a), pollinating insects [Apis mellifera L. (Hymenoptera: Apidae)] (Cintra et al, 2005a), leaf-cutting ant [Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae)] (Cintra et al, 2005b), predators [Iphiseiodes zuluagai Denmark and Muma (Acari: Phytoseiidae)] (Mourão et al, 2004b), and parasitoids [Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) and Telenomus remus Nixon (Hymenoptera: Scelionidae)] (Tavares et al, 2009). Bacillus thuringiensis also affected T. pretiosum parasitizing eggs of Anagasta kuehniella Zeller (Lepidoptera: Pyrallidae) (Vianna et al, 2009).…”

“…(Meliaceae) originated from Asia, is cultivated in several countries of America, Africa, and Aus-tralia and is one of the most important plants with insecticide activity and accentuated action against pests such as S. frugiperda (Lima et al, 2008;Santiago et al, 2008) and mites (Mourão et al, 2004a). Extracts from seeds of A. indica are used as insecticide in water-based and alcoholic solutions (Charbonneau et al, 2007).…”

Determination of Antioxidant Property and Minerals Contained in the Leaves ofAzadirachta indicaA. Juss

“…Correlações negativas foram observadas entre K e Ca (-0,87) e K e Mg (-0,83 (Rocha et al, 2007;Morais et al, 2009;Negri, Possamai e Nakashima, 2009;Nunes, 2011;). (Kraus et al, 1987;Mourão et al, 2004).…”

Germinação De Sementes De Nim (Azadirachta Indica A. Juss) Em Função Do Tipo De Coleta E Da Coloração Dos Frutos

“…É utilizado principalmente na forma de extratos aquosos ou orgânicos. Inúmeros trabalhos foram desenvolvidos por pesquisadores, avaliando a efetividade de extratos oriundos de diversas partes da planta de nim no combate a pragas, fungos e bactérias que atacam as mais diversas culturas alimentícias, a exemplo do tomate, café, couve e outras (SAITO et al 2004;MOURÃO et al 2004;COITINHO et al, 2006;DINIZ et al 2006;SANTOS et al 2006;TORRES et al 2006;VILLAR-GONZÁLES et al 2006). …”