Lethal and sublethal effects of ethyl cinnamate on Tuta absoluta eggs.

MARÍA EMILIA PÉREZ; MARÍA FLORENCIA AYLEN REINOSO; GUY SMAGGHE; GUSTAVO P. ROMANELLI; MARCELA I. SCHNEIDER; JUAN CARLOS AUTINO

Simposio; 66 International Symposium on Crop Protection; 2014

Integrated pest management (IPM) is a paradigm that promotes the integration of different pest control tactics, including the use of chemical selective compounds, with low impact on the environment. Then, the plant products represent an alternative to commonly used broad spectrum pesticides. Ethyl cinnamate is a secondary metabolite present in various plants. In previous research by our group, we found that this compound, at certain concentrations, produces an antifeedant effect in second larval-instar of Tuta absoluta (Lepidoptera: Gelechiidae), a worldwide relevant key tomato pest. The aim of this study was to evaluate the biological activity of ethyl cinnamate on eggs of different age (24 and 72 hours of development time from oviposition) of T. absoluta. Three concentrations of this compound (100, 250 and 500 µg/ml) were prepared by dissolution in acetone-distilled water, and a surfactant (Tween 80®) was added to each solution. Leaflets containing 5 eggs of 24 or 72 hours of development (experimental unit) were treated by immersion in each solution for 15 seconds. The leaflets were then dried under a fume hood and placed individually in plastic capsules. Each treatment was replicated 6 times. The lethal effects on the eggs and larvae, and larval emergence time were evaluated. At 48 hours post-emergence, each larva was individualized in a plastic capsule with untreated tomato leaflets. We also evaluated as sublethal effects: development time, weight of the pupa, adult emergence and fecundity and fertility of survived females. The data obtained were analyzed using one-way ANOVA test. The obtained results showed that the ethyl cinnamate at 500 µg/ml caused 100% mortality of eggs at both ages evaluated (24 and 72 hours). We observed a significant extension of development time to reach pupa and adult stage at 250 g/ml, although it was observed just in larvae emerged from treated eggs of 72 hours of development. In contrast, no biological activity was observed at 100 µg/ml. The results obtained will be discussed but as preliminary conclusion based on present results, the ethyl cinnamate represents a promising compound for the chemical control of T. absoluta.