Propriedade inseticida dos óleos essenciais de Piper hispidinervum C. DC.; Piper aduncum L. e Tanaecium nocturnum (Barb. Rodr.) Bur. & K. Shum sobre Tenebrio molitor L., 1758

Abstract

RESUMOÓleos essenciais das piperáceas Piper aduncum L., Piper hispidinervum C. DC. e da bignoniácea Tanaecium nocturnum (Barb. Rodr.) Bur. & K. Shum foram avaliados para o controle de larvas de Tenebrio molitor L., 1758. Para a avaliação do efeito por contato em superfície contaminada, foram utilizados papéis-filtro impregnados com diferentes quantidades dos óleos essenciais. Para a avaliação do efeito tópico foram aplicados 5 mL de soluções com diferentes concentrações dos óleos sobre larvas de quinto instar do inseto. A taxa de mortalidade foi a variável utilizada para avaliar os experimentos. Todos os óleos essenciais apresentaram efeito inseticida sobre larvas de T. molitor, sendo que as respostas variaram em função da concentração utilizada, assim como do método de exposição do inseto. A toxicidade dos óleos essenciais foi elevada apresentando os seguintes valores de CL 50 : 0,045; 0,033 e 1,515 mL de óleo cm -2 para exposição por contato (papel filtro) aos óleos de P. hispidinervum, P. aduncum e T. nocturnum, respectivamente. Para a aplicação tópica, os valores da DL 50 foram de: 0,000025; 0,009 e 0,000015 mL de óleo mg de inseto -1 para os óleos essenciais de P. hispidinervum, P. aduncum e T. nocturnum, respectivamente. Resultados promissores para o emprego desses óleos essenciais como inseticidas foram obtidos utilizando-se concentrações acima de 3,0% (v v -1 ) para P. hispidinervum e 2,5% (v v -1 ) para P. aduncum e T. nocturnum. Termos para indexação:Pimenta longa, dilapiol, safrol, mandelonitrila, inseticidas botânicos. ABSTRACTEssential oils from Piper aduncum L., Piper hispidinervum C. DC. (Piperaceae) and Tanaecium nocturnum (Barb. Rodr.) Bur.& K. Shum (Bignoniaceae) were tested against Tenebrio molitor L., 1758 larvaes. Filter paper with different amounts of oils were employed for contact toxicity effects study. For topical effect study, aliquots of 5 mL of oils at different concentrations were applied on larvaes of the fifth instar. Mortality rate was used to evaluate the assays. All essential oils possessed insecticidal effect to T. molitor, but the responses varied according to oil concentration and method of exposure. The toxicities of essential oils to T. molitor were elevated, with LC 50 of 0.045, 0.033 and 1.515 mL of the oil/cm 2 for contact (filter-paper) applications of the P. hispidinervum, P. aduncum and T. nocturnum oil, respectively. For topical application the values of the LD 50 were: 0.000025, 0.009 and 0.000015 mL of the oil /mg of the insect, for P. hispidinervum, P. aduncum and T. nocturnum oil, respectively. The most promising results for the use of such oils as insecticide were obtained using concentrations above 3,0% (v v -1 ) for P. hispidinervum and 2,5% (v v -1 ) for P. aduncum and T. nocturnum essential oils.

Bioactivity of essential oils from leaves and bark of Laurelia sempervirens and Drimys winteri against Acyrthosiphon pisum

“…The high toxicity of the essential oils from leaf and bark of L. sempervirens is not all that surprising given that safrole was one of the main metabolites in these extracts. Safrole is also the main constituent (82%) present in the essential oil of Piper hispidinervum DC., which has shown high insecticidal activity when applied topically on different pest insects such as Spodoptera frugiperda Smith larvae,39 Tenebrio molitor L. adults40 and Sitophilus zeamais Motsch adults 41…”

Toxicity of essential oils of Piper marginatum Jacq. against Tetranychus urticae Koch and Neoseiulus californicus (McGregor)

“…the mosquito Aedes aegypti and also serve as a deterrent to oviposition (Autran et al, 2009). The insecticidal activity of P. marginatum oil has been reported for other arthropods, such as Solenopsis saevissima (Souto et al, 2012), Tenebrio molitor (Fazolin et al, 2007), Sitophilus zeamais (Estrela et al, 2006;Coitinho et al, 2011), Tyrophagus putrescentiae and Suidasia pontifica (Assis et al, 2011). However, no previous study has evaluated the acaricidal action of P. marginatum oil on T. urticae and its natural enemy, N. californicus.…”

Piper aduncum against Haemonchus contortus isolates: cross resistance and the research of natural bioactive compounds

“…The diversity of this country's flora represents an enormous reservoir of mostly unexplored plant secondary compounds. Despite increasing research efforts to unveil new species and understand their roles over the past two decades, our knowledge remains scant (FAZOLIN et al, 2007). Nevertheless, different industrial sectors have increasingly sought Amazon plant compounds, including the agro-business sector.…”