(1R,6R)-2,2,6-Trimethyl-3-oxabicyclo[4.2.0]octan-4-one, a new monoterpene lactone produced by males of the cocoa borer Conotrachelus humeropictus (Col.: Curculionidae)

Abstract The cocoa weevil Conotrachelus humeropictus is an economically most important pest on cocoa ( Theobroma cacao ) and cupuacu ( Theobroma grandiflorum ) cultures. Knowledge on the pheromone system of this insect is prerequisite for the development of an integrated pest management system. GC/MS-analysis of headspace volatiles revealed the presence of three male specific compounds, which were identified to be (1 R ,2 S )-grandisol, (1 R ,2 S )-grandisoic acid, and the new bicyclic terpene lactone (1 R ,6 R )-2,2,6-trimethyl-3-oxabicyclo[4.2.0]octan-4-one, which we term grandisolide.