Effects of Extracts of Larrea divaricata Against the Stored Product Pests Tribolium castaneum (Coleoptera: Tenebrionidae).

LUDMILA FUCHS; JORGE OYENART; MARIA ROSANA RAMIREZ

virtual

Congreso; Reunion anual de sociedades de biociencias; 2020

Several shrubs belonging to genus Larrea (Zygophyllaceae) occur in semi-arid region from Argentina and are used in traditional medicine to treat fungal and bacterial infections. The most common species is Larrea divaricata, known as female jarilla. The ethanolic extract of L. divaricata leaves has reported as antifungal when tested against S. cervisiae, C. albicans y A. niger. Nordihydroguaiaretic acid (NDGA), found in the resin of leaves and stems, has inhibitory effects on the ecdysis of Rhodnius prolixus; and extends the life cycle of Aedes Aegypti. Members of the Zygophyllaceae family have demonstrated larvicidal activity against Cx. Pipiens, antifeeding and repellent activity against Sitophilus oryzae. However, no studies were found on the bioactivity of L. divaricta against the cereal pest Tribolium castaneum (Tenebrionidae). The storage pest T. castaneum is a major pest of both raw and processed commodities. This study was designed to evaluate the bioactivity of L. divaricata, against the T castaneum. Samples were collected, in the province of La Pampa. The phytochemical extraction was performed using organic solvent extraction as well as aqueous extraction, according to conventional techniques. T. castaneum, two stages, larvae and adults were used (10 insects per well), four doses (2.5 to 50 mg) were evaluated, in triplicate. The solid resin was tested on the one hand, and the methanol extract on the other. The number of dead insects was recorded every 24 hours for 7 days post treatment. Comparisons among groups of data were done using one-way ANOVA, an associated probability of P