STRUCTURE, CHIRALITY, AND FIELD TESTING OF A MALE-PRODUCED AGGREGATION PHEROMONE OF ASIAN PALM WEEVIL RHYNCHOPHORUS-BILINEATUS (MONTR) (COLEOPTERA, CURCULIONIDAE)

4-Methyl-5-nonanol is a male-produced aggregation pheromone of the Asian palm weevil, Rhynchophorus bilineatus (Montr.). The pheromone was identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled GC-mass spectrometric (MS) analyses of male- and female-produced volatiles. Analyses by GC-EAD and GC-MS of weevil-produced and stereoselectively synthesized isomers of 4-methyl-5-nonanol on a Cyclodex B column, which separated isomers with baseline resolution, revealed that only (4S,5S)-4-methyl-5-nonanol is EAD active and produced by the males. In field experiments in Papua New Guinea, (4S,SS)-4-methyl-5-nonanol and a racemic mixture of disatereoisomers of it enhanced attraction of male and female weevils to sugarcane-baited traps. (4S,5S)-4-Methyl-5-nonanol is also an aggregation pheromone of two other Asian palm weevils, R. ferrugineus (Oliv.) and R. vulneratus (Panz.). The stereoisomeric mixture of 4-methyl-5-nonanol is currently used to manage populations of R. bilineatus in Papua New Guinea.