Ítalo Chiffelle1, Amanda Huerta2, Valentina Bobadilla2, Gonzalo Macuada2, Jaime E. Araya1, Tomislav Curkovic1, and Ricardo Ceballos3*
Xanthogaleruca luteola (Coleoptera: Chrysomelidae) is an aggressive defoliating pest on elms (Ulmus sp.) worldwide. We evaluated the antifeedant and insecticidal effects of ethanolic and aqueous extracts from Melia azedarach L. green fruits and leaves of Peumus boldus Molina, on X. luteola third instar larvae, the most harmful stage. Five doses of the extracts were applied to fresh elm leaves to determine antifeedant effect evaluating consumed foliar area at 24 h. Insecticidal activity was assessed through daily mortality for 14 d. For each extract an antifeedant index, relative to respective control, and mean lethal concentrations (LC50) were calculated. We found a direct relationship between concentration and both antifeedant and insecticidal effects for all extracts. A dose of 6.1% w/v of ethanolic extract of M. azedarach green fruits significantly inhibited larvae feeding behavior by 91% with a LC50 1.49% at day 8. On the other hand, 3.4% w/v of ethanolic extract of P. boldus inhibited larvae feeding behavior by 81% and LC50 at day 8 was 0.92% w/v. All extracts showed insecticidal effect on X. luteola larvae, and the highest mortalities observed were 79% and 71% with ethanolic and aqueous extracts of P. boldus, respectively. Antifeedant and insecticidal effects observed with M. azedarach green fruits and P. boldus leaf extracts on X. luteola third instar larvae,support the development of botanical
Key words: Antifeedant effects, insecticidal effects, Melia azedarach, Peumus boldus, Xanthogaleruca luteola.
1Universidad de Chile, Facultad de Ciencias Agronómicas, Av. Santa Rosa 11315, Santiago, Chile.
2Universidad de Chile, Facultad de Ciencias Forestales y de la Conservación de la Naturaleza, Av. Santa Rosa 11315, Santiago, Chile.
3Instituto de Investigaciones Agropecuarias, INIA Quilamapu, Av. Vicente Méndez 515, Chillán, Chile.
*Corresponding author (email@example.com).