Identification and field evaluation of (E)-11,13-tetradecadienal as sex pheromone of the strawberry tortrix (Acleris comariana)

Abstract

The strawberry tortrix (Acleris comariana Lienig and Zeller) (Lepidoptera: Tortricidae), is a major pest of strawberry in Denmark and southern Sweden. Chemical and electrophysiological analyses revealed a single compound, (E)-11,13-tetradecadienal (E11,13-14:Ald), in gland extracts of females eliciting a strong antennal response in conspecific males. Also (Z)-11,13-tetradecadienal (Z11,13-14:Ald) was found to be antennally active, but not detected in gland extracts. The corresponding alcohol and acetate of E11,13-14:Ald, which are biologically active in other Acleris species, were not produced by females and did not trigger electrophysiological response in males. Trapping experiments at a commercial strawberry farm in southern Sweden showed that E11,13-14:Ald and Z11,13-14:Ald, alone or in combination, attracted large numbers of males. Trap catches increased with increasing dose of E11,13-14:Ald, with traps baited with 100 µg and 1,000 µg being most attractive. Our results confirm the widespread use of E11,13-14:Ald as a key sex pheromone component in the genus Acleris. The identification of a highly attractive sex pheromone is a first step in developing pheromone-based methods for monitoring and control of A. comariana in European strawberry production.