Insecticidal Activity of Four Medicinal Plants against Stored Grain Borer, Rhyzopertha dominica (Fabricius)

The lesser grain borer Rhyzopertha dominica (Fab.) is a major pest that causes damage to post-harvest wheat products. A promising alternative to traditional neurotoxic insecticides in pest management is biopesticides. This study evaluated essential oils (EOs) from four medicinal and aromatic plants for their insecticidal activity under laboratory conditions. All four EOs were repellent and caused fumigant toxicity to R. domonica. The treatments were given at 5, 10, 15, and 20% (w/v). Maximum repellency was recorded after Tridax procumbens EO treatment (92.8%), followed by Citrus sinensis, Rauwolfia serpentina, and Curcuma longa EOs. After 48 h exposure, the lethal concentration values of T. procumbens EO were 9.716 μL and 13.062 μL against larvae and adults of R. domonica, respectively. Therefore, from the above findings, these four EOs could be an effective natural biopesticide for controlling R. domonica..