Identification of volatile compounds from female glands involved in Copitarsia uncilata sex attraction

Copitarsia species cause serious crop damages and economic losses, being quarantine pests of rigorous control at US entry ports. In Colombia, Copitarsia uncilata is a serious plague of cut flowers. Recent methods to control this pest are based on the use of semiochemicals, since this strategy triggers a behavioral alteration of male. However,  a successful result is guaranteed if pheromone composition is known and its role in attraction is demonstrated by behavioral response. Accordingly, the aim of the present study was oriented to identify the pheromone-related compounds of C. uncilata females associated with the intraspecific communication. Different volatile capture methods from calling females were used, i.e., Porapak-Q, SPME, but also solvent-assisted extraction from female ovipositor and male genitalia. Adsorbed/extracted compounds were analyzed by GC-MS. This analysis led to identify 5 components related to type-I pheromone compounds, i.e., Z9:14OH, Z9:14Ac, 14:Ac, 18:OH and Z9-18:Ald. Ratio of C14-containing components were found to be at 10:1 and 5:1 in glandular and Porapak-Q-captured mixtures, respectively. These two compounds were also evaluated in wind tunnel using different proportions, including two positive controls (i.e., virgin females and a bioactive glandular extract). Activation, take off, oriented flight, source landing and courtship were registered. This assay showed that >20% of test males performed oriented flight, >65% of males exposed to the conspecific female calling, and >70% exposed to the bioactive extract landed at the source. Results indicate a suitable route for developing an ethological control tool as preliminary phase. This study was funded by UMNG project INV-CIAS-3142.