Optimization of pheromone lure and trap design for monitoring the fir coneworm, Dioryctriaabietivorella

The major components of the sex pheromone of Dioryctria abietivorella (Groté) (Lepidoptera: Pyralidae) were recently identified as (9 Z ,11 E )-tetradecadien-1-yl acetate (9 Z ,11 E -14:Ac) and a polyunsaturated, long-chain hydrocarbon (3 Z ,6 Z ,9 Z ,12 Z ,15 Z )-pentacosapentaene (C25 pentaene). The optimal ratio of these components and the role of potential minor components were not fully determined in the initial short report on the pheromone’s identification. We tested different ratios of the two major components loaded into grey halobutyl rubber septum dispensers, placed in sticky traps deployed in conifer breeding arboreta. The optimal ratio of the two components was 200 μ g 9 Z ,11 E -14:Ac to 2000 μ g C25 pentaene. ( Z )-9-Tetradecen-1-yl acetate, which had been identified previously in female pheromone gland extracts, and five other potential minor pheromone components, were tested individually as additions to the optimized two-component lure blend. None of the ternary blends were more attractive than the optimized two-component blend, at the ratios tested. Two lure adjuvants, a UV stabilizer (Sumisorb 300) and the antioxidant butylated hydroxytoluene, added individually or together, did not affect the attractiveness of the optimized lure blend. The Pherotech diamond sticky trap baited with the optimized lure blend was the most effective trap design among eight types of sticky trap and a bucket style trap that were tested. Traps baited with synthetic lures were as attractive as traps baited with virgin female moths. The optimized two-component lure blend in the Pherotech diamond trap is recommended for monitoring fir coneworm infestations. The availability of an effective synthetic pheromone opens the possibility for control tactics using mating disruption or attract-and-kill techniques.