Effect of pine bark beetle infestation by determining volatile organic compounds in the Sierra de Quila Flora and Fauna Protection Area (APFFSQ), Jalisco, Mexico

Abstract

Volatile organic compounds were determined in two species of pines, with different phases of infestation by debarking beetles of genera Dendroctonus and Ips, in the Sierra de Quila Natural Protected Area, Jalisco, located in western Mexico. In 2016, needles of Pine douglasiana and Pinus oocarpa were collected, in phase 1, 2 and 3 of infestation, as well as from healthy trees; with this material, extractions were carried out with constant cold agitation. The extracts obtained were analyzed by gas chromatography-mass spectrometry (GC-MS), identifying about 15 compounds for healthy trees. These secondary metabolites were mostly monoterpenes such as α and β-pinene, limonene, and 3-carene; only two sesquiterpenes in common (β-copaene and caryophyllene) were present. In the extracts of infested pines, sesquiterpenes and their derivatives were increased to 10 compounds, including δ-cadinene, longifolene, γ-cadinene, γ-muurolene, 8-hydroxy-endo-cycloisolongifolene, and α-cadinol. Our study shows how chemical composition of volatile organic compounds in pine trees attacked by debarking beetles increased and was more varied. These results have a great applicability since they can be useful for the establishment of an integrated management of forest pests.