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Speakers - Jan Bergmann

Type of the Presentation: (Short lecture)

 

The pheromone of Chilecomadia valdiviana (Lepidoptera: Cossidae): identification, synthesis, and biosynthesis

 

Jan Bergmann, Heidy Herrera

 

1  Instituto de Química, Pontificia Universidad Católica de Valparaíso, Chile

*  Correspondence: jan.bergmann@ucv.cl

 

Chilecomadia valdiviana (Philippi) (Lepidoptera: Cossidae) is an insect native to Chile. The larval stages feed on the wood of economically important fruit tree species such as apple, pear, olive, cherry, avocado, and also on eucalyptus, which causes weakening  and in case of severe infestation death of the tree. In order to set the basis for the development of control methods, we identified the sex pheromone of this species. Hexane extracts of the abdominal glands of virgin females were analyzed by gas chromatography (GC) with electroantennographic detection, GC coupled with mass spectrometry, and GC coupled to infrared spectroscopy. The major pheromone component was identified to be (7Z,10Z)-7,10-hexadecadienal (Z7,Z10-16:Ald), whereas minor components present in the extracts proved to be (Z)-7-hexadecenal and (Z)-9-hexadecenal, hexadecanal, and (9Z,12Z)-9,12-octadecadienal. Structure assignments were carried out by comparison of analytical data of the natural products and their dimethyl disulfide adducts with those of authentic reference samples. In field tests, traps baited with Z7,Z10-16:Ald attracted large numbers of males and captured significantly more males than control traps. The structure of the main compound suggested a biosynthesis via a linoleic acid precursor. Topical application of deuterated linoleic acid to the pheromone gland of virgin females resulted in the incorporation of the deuterium label into the pheromone compound.