38 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



The structures which cover and protect the genitalia proper are 

 the seventh sternite and the eighth tergites. The seventh sternite 

 (figs. 57-74) is usually widened at the base, and the posterior mar- 

 gin may be toothed or scalloped in some fashion. It has limited sys- 

 tematic value. Protecting the genitalia dorsally and laterally are two 

 curved sclerites, one on each side, each terminating ventroposteriorly 

 in a pair of distinct prongs (figs. 12-29). These are called the accessory 

 claspers for lack of a better term, since the term "clasper" as used in 

 the Lepidoptera usually refers to the valvae (=harpae=parameres). 

 The accessory claspers are loosely connected dorsally by a membrane, 

 and they are believed to be the modified eighth tergum. The accessory 

 claspers are relatively constant in general size and shape, and have 

 some systematic value. They apparently serve for holding the female 

 since they are capable of opposable movements. 



The terminology used in describing the genitalia proper is basically 

 that of Snodgrass (1957) with the substitution of more specific terms 

 for some structures. The ventral portion of the genitalia is the modified 

 eighth sternite (figs. 37-54). It is "U"-shaped, with the "arms" of 

 the U tapering backward into sharp points. The overall shape and 

 size of the eighth sternite is characteristic for most species, and the 

 lateral arc of curvature of the points near the tip (fig. 40) is helpful in 

 separating some species. Attached to the dorsal surface of the eighth 

 sternite is the pouchlike, modified ninth sternite known as the saccus. 

 Extending posteriorly and fused with the posterior part of the saccus 

 is a pair of fingerlike structures that make an abrupt, nearly right- 

 angle turn downward, projecting between and past the arms of the 

 eighth sternite. These are known as the parameres (valvae or harpae) 

 and they are connected by an interparameral bridge. They have some 

 systematic value. The vesica bears no cornuti and has no systematic 

 value. Posteriorly, the ninth tergum is modified to form a sclerotized 

 area known as the tegumen. The alimentary canal passes between the 

 base of the aedeagus and the dorsal parts of the accessory claspers, ter- 

 minating in a central membranous area partially surrounded by the 

 tegumen. The anus is centered in this membranous area and lies be- 

 tween two small "hairy" projections on the tegumen known as the socii. 

 The tegumen and socii have little systematic value. Several parts of 

 the terminalia bear numerous small setae, bristles, scales, etc., but 

 none of these have been found to be of systematic value, and they 

 are not included in the illustrations. 



