Electrophysiological and behavioral responses of Dendroctonus valens to non-host volatiles.
Non-host volatiles (NHVs) that are often reported as being disruptive to coniferophagous bark beetles were tested for both electrophysiological and behavioural effects on the red turpentine beetle, Dendroctonus valens (Coleoptera: Curculionidae: Scolytinae), which was accidentally introduced into China in the mid-1980's. D. valens were collected from a Pinus tabulaeformis plantation at Tunlanchuan Forest Station, Gujiao City, Shanxi province, China. All NHVs tested elicited dose-dependent antennal responses by D. valens. In Y-tube olfactometer trials, D. valens were repelled by NHVs tested. When NHVs were added to a kairomone blend, responses of D. valens were significantly inhibited. Further field trapping experiments showed that attraction of D. valens to kairomone baited traps was reduced by all individual NHVs, with reductions ranging from 26.3 to 70%. 1-Octen-3-ol, (Z)-3-hexen-1-ol, and (E)-2-hexen-1-ol were the three most effective NHVs, significantly reducing D. valens to kairomone-baited traps by 69.5, 68.3 and 66.0%, respectively. In the development and implementation of a semiochemical-based management programme for D. valens, NHVs may have considerable potential for disrupting the beetle's ability to locate suitable hosts.