Male Genitalia of Lepidoptera: Morphology and Nomenclature II. Morphological Significance of Sacculus and Furca

Abstract

The sacculus (named by Pierce, 1909) is a reflected flange of the sclerotized part of the valva, occupying the ventroproximal portion on its mesal surface. Such a morphological element is widely found in the male genital apparatus of most specialized forms of Lepidoptera. However, the degree of development is subject to great variation in individual species, and sometimes even its presence may become obscure. The same situation is also encountered in the male genitalia of more primitive forms. The observation throughout all the lepidopterous families now makes it evident that the development of the sacculus has close relationships to the position of the juxta (Pierce, 1909) in relation to both the bottom of the vinculum and the valva; the association of the sacculus with the juxta is noteworthy as one of general rules in the morphology of male genitalia in Lepidoptera.