For details of the abdomen please see the figure under 'Thorax'
The abdomen consists of ten segments but segments 7-10 may be greatly modified in association with the external genitalia. Tympanal organs are present in the abdomen base in the Geometroidea, Drepanoidea and Pyraloidea. The Thyridoidea do not have this type of tympanal organ. The abdomen (and sometimes other parts of the bodies) of male moths houses a variety of glandular organs, normally associated with a wide variety of eversible, expansible tufts or brushes of hair scales. These hair pencils, most noticeably found on the tibiae of the legs and around the genital opening, disperse pheromones which act as aphrodisiacs and ensure sucessful mating.