Insecticidal and growth inhibiting action of the supercritical extracts of Melia azedarach on Spodoptera frugiperda

Abstract

A B S T R A C TThis study evaluates the effects of supercritical carbon dioxide extracts obtained from the fruit of Melia azedarach L. (Meliaceae) on the development of Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae), from the larval period until the insect adulthood. For this purpose, a laboratory-scale extraction unit was operated at 60 °C and 200 bar. Larval mortality increased by raising the extract concentration tested: the value of LC 50 calculated by Probit analysis was 376.74 mg kg -1 , and at a concentration of 5000 mg kg -1 , the mortality was 100%. The extract exhibited insect growth inhibitory activity in the higher concentrations (500 mg kg -1 , 1000 mg kg -1 and 5000 mg kg -1 ), due to antifeedant action, resulting in larvae and pupae with mass and body length significantly smaller than the control. At the lowest concentration tested (100 mg kg -1 ), bioactive effects from the adult stage of the insect were observed, with low viability pupal and adults presenting morphological deformities, hence indicating chronic toxicity effect.Ação inseticida e inibitória de crescimento de extratos supercríticos de Melia azedarach sobre Spodoptera frugiperda R E S U M O Este estudo avaliou os efeitos do extrato de frutos de Melia azedarach L. (Meliaceae) obtido através do solvente dióxido de carbono supercrítico sobre o desenvolvimento de Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae), desde o período larval até a fase adulta do inseto. Para obtenção do extrato, uma unidade de extração em escala laboratorial foi operada a 60 °C e 200 bar. O extrato, quando adicionado à dieta artificial das larvas, demonstrou ação inseticida, a CL50 calculada através da análise de Probit foi de 376,74 mg kg -1 , na concentração de 5000 mg kg -1 e a mortalidade foi de 100%. Nas concentrações mais elevadas (500, 1000 e 5000 mg kg -1 ) o extrato apresentou também atividade inibitória de crescimento nos insetos, devido à ação antialimentar, resultando em larvas e pupas com massa e comprimento corporal significativamente menores que o controle. Na menor concentração testada (100 mg kg -1 ) foram observados efeitos bioativos a partir da fase adulta do inseto, como baixa viabilidade de pupas e adultos com deformações morfológicas, indicando, portanto, efeito de toxicidade crônica.

Impact of sesquiterpenes from Inula racemosa (Asteraceae) on growth, development and nutrition of Spodoptera litura (Lepidoptera: Noctuidae)

“…Data on the fecundity of adults emerged from larvae reared on alantolactone‐ and isoalantolactone‐amended diet could not be recorded because of the smaller number of adults and reduced female longevity, but lower pupal weight is expected to have a negative impact on the reproductive potential of S. litura . The pupal weight has a high correlation with the fecundity of the adults, and the reduction in fertility is one of the main effects reported in adults from smaller pupae, thus reducing the number of eggs, which has also been found in insects that were fed on diets containing plant extracts …”

“…The pupal weight has a high correlation with the fecundity of the adults, and the reduction in fertility is one of the main effects reported in adults from smaller pupae, thus reducing the number of eggs, which has also been found in insects that were fed on diets containing plant extracts. 56,57 Sublethal effects of both the sesquiterpenes were also evident from the development of malformed pupae and adults at higher concentrations. The larvae died prematurely in half cast moults or developed into larval pupal intermediates.…”

Plant extracts, metaldehyde and saline solutions on the population control of Bradybaena similaris

“…The main metabolites of these plants are the azadirachtin and the melianona (ROSSI et al, 2007). The oil from M. azedarach was successfully tested as an inhibitor of the larval development of Spodoptera frugiperda (Smith, 1797) (Lepidoptera) (SCAPINELLO et al, 2014). Nevertheless, in this study the pure extract of M. azedarach did not present any molluscicidal activity on B. similaris.…”

Potencial Larvicida De Melia Azedarach L. E Ilex Paraguariensis St. Hil. No Controle De Aedes Aegypti (Linnaeus, 1762) (Diptera: Culicidae)

“…Em estudo realizado por Scapinello et al (2014), foi testado extrato do fruto de M. azedarach obtido através do solvente dióxido de carbono supercrítico sobre o desenvolvimento de Spodoptera frugiperda (SMITH, 1797) do período larval até a fase adulta, onde observou-se que a viabilidade das larvas de S. frugiperda foi significativamente alterada pela presença do extrato, com uma redução da viabilidade proporcional ao aumento da concentração de extrato adicionado à dieta. A ação larvicida da M. azedarach está associada à presença de compostos da classe dos terpenos, como, por exemplo, a melianona e a azadiractina, que têm comprovada ação sobre larvas e insetos (FREITAS, 2008;ROSSI et al, 2007).…”