Behavioral responses of Araecerus fasciculatus (Coleoptera: Anthribidae) to volatiles of selected stored Chinese medicinal plant products.

The olfactory responses of Araecerus fasciculatus Degeer to the volatiles of 5 traditional Chinese medicine plant products (CMPPs; i.e., Codonopsis pilosula Franch., Ophiopogon japonicus Linn. f., Astragalus membranaceus Fisch., Dendrobium nobile Lindl., and Angelica dahurica Fisch.) were studied using Y-tube, 4-arm, and 6-arm olfactometers. The volatile components of these CMPPs were analyzed using gas chromatography-mass spectrometry (GC-MS). A. fasciculatus significantly preferred the CMPPs volatiles in the order of O. japonicus > C. pilosula > A. membranaceus ≥ D. nobile = A. dahurica. In the volatile profiles of O. japonicus, C. pilosula, A. membranaceus, D. nobile, and A. dahurica, GC-MS identified 27, 61, 63, 52, and 71 components, respectively, and β-elemene (30.58%), hexanal (12.69%), selina-3,7(11)-diene (12.31%), d-limonene (18.59%), and α-curcumene (8.88%) were the most abundant volatile components. A. fasciculatus were attracted to β-elemene, α-selinene, and β-selinene (main components of the volatile profiles of the most preferred CMPPs of O. japonicus) at different concentrations, with 1, 50, and 25 µg/µl being the most attractive, respectively. The olfactory preferences of A. fasciculatus were β-elemene > α-selinene = β-selinene based on the 4-arm olfactometer bioassays for comparisons at their most attractive concentrations. Therefore, differences in the volatile profiles among CMPPs significantly influenced the olfactory responses of A. fasciculatus, offering insight into the mechanisms of host preferences in stored-product pests based on chemical ecology. β-elemene showed the greatest potential to be developed as an attractant for the monitoring and control of this pest.