Analysis of sex pheromone gland content of individual Symmetrischema tangolias by means of direct gland introduction into a two-dimensional gas chromatograph

The amounts and ratios of the four constituents of the sex pheromone gland of the moth Symmetrischema tangolias were measured during a 24-hr dark–light cycle. A new approach was followed that involved the direct introduction of sex pheromone glands into the liner of a two-dimensional gas chromatograph (2D-GC) by using a special temperature programmable GC injector. With this method it was possible to examine individual glands without prior processing. This provides a clear advantage over other methods. The detection limit was 0.5 ng. The total amount of sex pheromone in the glands varied strongly from individual to individual (3.8–350 ng/female). The total sex pheromone amounts were significantly lower in the scotophase than in the photophase (62.2 and 101.5 ng/female, respectively). The ratios of the various gland constituents showed a symmetrical distribution, which did not fluctuate during the 24-hr dark–light cycle