Catching Ips duplicatus (Sahlberg) (Coleoptera: Scolytidae) with pheromone-baited traps: optimal trap type, colour, height and distance to infestation.

BACKGROUND: Field trapping experiments were carried out to evaluate effective trap characteristics for maximising Ips duplicatus (Sahlberg) catches in pheromone-baited traps in China.
RESULTS: Window-slot and cross-barrier traps had significantly higher catches than multiple-funnel traps. The colour of window-slot traps showed a significant effect on catches, with dark colours (black and red) being more effective than light colours, especially white and yellow. Window-slot traps at a 1.5-2.0 m level caught more beetles than those at either ground level (0-0.5 m) or at 3.5-4.0 m. Ips duplicatus can be attracted to pheromone-baited traps over a distance of > 100 m from the forest edge in an open grassy field. There was a strong diurnal pattern of flight activity, with catches on window-slot traps occurring during the daytime with one broad peak at mid- to late afternoon. The seasonal flight activity of I. duplicatus as monitored by pheromone-baited window-slot traps during 2007-2008 indicated that three major flight peaks occurred in early June, late June-early July and late July respectively, suggesting the existence of a potential second generation.
CONCLUSION: The optimal trap characteristics will improve the performance of pheromone-baited traps as a critical monitoring or mass-trapping tool to combat outbreaks of this pest species.