Chemical composition and insecticidal activity of essential oils from Piper coruscans Kunt, Piper ottoniaefolium C. DC. and Piper reticulatum L. against Sitophilus zeamais Motschulsky

Biocides based on essential oils (EOs) have emerged as a novel class of pest control agents due to their multifaceted bioactive properties and natural origin, which confer a reduced environmental impact. This research focused on the study of the volatile chemical composition and the repellent and fumigant activities of EOs extracted from the aerial parts of Piper coruscans Kunt, Piper ottoniaefolium C. DC. and Piper reticulatum L., originating from the Colombian Pacific flora, on the corn weevil Sitophilus zeamais Motschulsky. The EOs were obtained by hydrodistillation and identified by GC–MS. The main components found in P. coruscans were caryophyllene oxide (31.75%), and β-selinene (10.29%), in P. ottoniaefolium were β-bisabolene (14.46%), and α-curcumene (8.36%), and in P. reticulatum were caryophyllene oxide (9.44%), and β-caryophyllene (9.01%). The repellent activity was determined by the preference area method at 2.5 μg cm-2 and 2 h of exposure, in which the EO of P. ottoniaefolium obtained a percentage of repellency of 83.3%, higher than P. coruscans and P. reticulatum 66.7% and 36.7%, respectively against S. zeamais. Similarly, in the fumigant activity, the P. ottoniaefolium EO was more effective with an LC50 = 3.56 μL cm-3 compared to P. reticulatum = 6.12 μL cm-3 and P. coruscans = 7.43 μL cm-3. The results indicated that the EOs of these three Piperaceae have considerable insecticidal potential against S. zeamais and could be an alternative for the formulation of new biopesticide products.