Identification and Field Evaluation of Sex Pheromone Components of the Pear Barkminer Moth, Spulerina astaurota

Abstract

The pear barkminer moth, Spulerina astaurota Meyrick (Gracillariidae: Gracillariinae), is a harmful pest of the Asian-pear tree. Pheromone components of the female were analyzed by gas chromatography (GC) with an electroantennographic (EAG) detector and GC coupled with mass spectrometry. The analyses of a crude pheromone extract and those of a fractionated extract on a Florisil column indicated three EAG-active components, tetradecadien-1-ol, its acetate, and an aldehyde derivative. Characteristic fragment ions in the mass spectra of the dienyl compounds and derivatives with 4-methyl-1,2,4-triazoline-3,5-dione revealed double bonds at the 9- and 11-positions. By comparing the chromatographic behaviors to those of four authentic geometrical isomers, which were synthesized by three different routes starting from 1,8-octanediol or 1,9-nonanediol, the configuration of each natural component was assigned to be 9Z,11Z; i.e., it was concluded that the S. astaurota females secreted (9Z,11Z)-9,11-tetradecadien-1-ol (Z9,Z11-14:OH) as a main pheromone component, and the acetate and aldehyde derivatives (Z9,Z11-14:OAc and Z9,Z11-14:Ald) as minor components. This identification was confirmed by a field evaluation of the synthetic pheromone. While the male moths could be attracted to a lure baited with Z9,Z11-14:OH alone, Z9,Z11-14:OAc showed a strong synergistic effect on the attraction. Among the lures tested, the mixture of alcohol and acetate in a ratio of 7:3 exhibited the strongest attraction. Addition of Z9,Z11-14:Ald in the mixture did not significantly increase the number of males attracted. Furthermore, the field test indicated that some contamination of a geometrical isomer of the alcohol did not impair the activity of the binary mixture with the 9Z,11Z configuration.

Structure, Synthesis, and Bioassays of Sex Pheromone for Pyrausta machaeralis (Lepidoptera: Crambidae)

“…Acetylation of 2 with acetic anhydride and pyridine in dichloromethane produced monoacetate 3 after flash chromatography. A coupling reaction of 3 with butyllithium (BuLi) and 1-butyne in a mixed solvent of THF and HMPA produced a tetradic-11-en-1-yl ( 4 ) . From 4, E 11-14:Ac ( 5 ) was prepared by partial reduction of the triple bond utilizing dicyclohexylborane …”

“…A coupling reaction of 3 with butyllithium (BuLi) and 1-butyne in a mixed solvent of THF and HMPA produced a tetradic-11-en-1-yl ( 4 ) . From 4, E 11-14:Ac ( 5 ) was prepared by partial reduction of the triple bond utilizing dicyclohexylborane Figure S3).…”

“…23 From 4, E11-14:Ac (5) was prepared by partial reduction of the triple bond utilizing dicyclohexylborane. 23 EAG Response. An EAG coupled with a probe/micromanipulator (MP-15), a data acquisition interface box (IDAC-2), and a stimulus controller (CS-55) were used for EAG recordings.…”