PHENOLIC COMPOUNDS AS BIOPESTICIDES FOR Sitophilus zeamais

RODRIGUEZ A; MERLO C ; ZUNINO MP; USSEGLIO VL; DAMBOLENA JS; BEATO M ; ZYGADLO JA

Buenos Aires

Congreso; 6th Congress of the Latin American Association of Chemical Ecology; 2021

The insect Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), known as the maize weevil,produces significant economic losses during the storage of these grains in Argentina. The damagecaused by S. zeamais infestations is usually of two types: direct damage, which is caused by the consumption of the grain, and indirect damage caused by secondary pests such as bacteria and fungi. In the silo infestation, the insect´s olfactory perception of the VOCs acquires great importance since it influences on the most important behavior patterns, such as the search for food, partner and oviposition site. Based on this, our objective was to evaluate the effect of 10 natural phenolic compounds on the behavior and survival of S. zeamais. For this, a repellent/attraction test, using a two-ways olfactometer, and a contact toxicity assay were carried on. In this study we observed that the thymol, phenol and p-cymene present a repellent effect on S. zeamais while the guaiacol, m-cresol and vanillin were attractive to this insect. On the other hand, the o-creosol and thymol present the highest insecticidal activity. In relation with this, structural and physicochemical properties of the chemical compounds, such as the pKa, number and position of -OH groups and the chirality of principal carbon, among others, are related with its bioactivity and efficacy. Traditionally, the control of S. zeamais is carried out using synthetic pesticides, which cause several damages in the environment and human health. For this reason, the study of the bioactivity of natural compounds to ensure food safety has become of great importance.