Biological activity of extracts from Vernonanthura nebularum

DÍAZ M.; COSTA C.; SALVATORE A.; MURÚA G.; BARDÓN A.; VERA N.; BORKOSKY S.

Tafí del Valle

Jornada; XXVII Jornadas Científicas, Asociación de Biología de Tucumán; 2011

Asociación de Biología de Tucumán

Plants continue to be the subject of novel and straightforward applications as biological control agents, with high safety levels and low environmental impact. Following this interest, we present here the insecticidal and molluscicidal activity of different extracts from V. nebularum, an endemic plant from the northwest of Argentina. The extracts were incorporated into the diet of 2nd instar larvae of Spodoptera frugiperda, at a dose of 300 ìg of extract per g of diet. We evaluated the effects on the feeding behavior (choice test). Methanol and methylene chloride extracts were the most active ones, with 79% and 83% antifeedant effects, respectively. The acute toxicity molluscicidal test was undertaken to determine the lethal concentration 50 (LC50) to Biomphalaria peregrina, the potential vector of the parasitic disease schistosomiasis in Argentina. The snails were placed in 20 mL beakers containing aqueous solutions of the extracts (100 and 50 ìg /mL) in the absence of food. Snail lethality was evaluated after 24 hours of exposure. Our results yielded LC50 values of 97, 47, and 43 ìg /mL for methylene chloride extract, and ethyl acetate and methylene chloride subextracts, respectively. Previous phytochemical studies carried on V. nebularum revealed the presence of sesquiterpene lactones that could play a significant role in the activities observed.