213 



X- and Y-structures could possibly be via, which then would be in a rather primitive 

 position; compare Nahiiblattella, fig. 328b). 



Ventral lobe via Parcoblatta and Blaberus have retained a distinct vla-lobe. Like in 

 Nahublattella, however, the L4-plate in the ventral vla-wall has been lost (compare e.g. 

 L4G in Anaplecta, fig. 205). 



The vla-lobe of Blaberus (fig. 297a, 299: beneath the via-process) can be identified as the 

 true via by some of its features in common with Nahublattella and other species: The 

 dorsal vla-wall continues anteriad into the ventral Ive-wall (fig. 12, 181, 246, 300). The 

 ventral vla-wall is part of the ventral wall of the left complex (fig. 6, 174, 239a, 297a). 

 The dorsal and ventral vla-walls are connected by a very stout muscle (16b in fig. 18, 188, 

 189, 251, 252, 305, 306). In contrast to all other species, however, Blaberus has the dorsal 

 insertion of 16b on the L2-sclerotisation. This is a consequence of the rotation of via and 

 of the posterior parts of L2 described above, by which extensive parts of L2 must have 

 shifted into the insertion area of 16b. 



Parcoblatta has a similar vla-lobe (fig. 268-270), which, however, lies to the left and dorsal 

 to the via-process. This location corresponds to the rotation of via and of the genital 

 opening described above, in which via has been involved, too. Muscle 16b (fig.278, 279) 

 is in the same position as in Blaberus; its dorsal insertion, however, is on the membranous 

 parts of the Ive-pouch wrapped around the L2-sclerite; this situation is, again, an effect 

 of the rotation. 



In the other species (fig. 328c, d,f,g,h,i; 16b not investigated) there is no distinct lobe via. 

 By comparing the relative positions of the phallomere elements adjacent to the vla-lobe 

 in Blaberus and Parcoblatta, however, a membranous area that is assumed to be the last 

 vesfige of via (fig.328c,d,h,i) can be determined. Only in Loboptera (fig.328f) and 

 Ectobius (fig.328g) this is not possible because of extensive reductions in this part of the 

 left complex. 



A sclerotisation LIO on via is only present in Blaberus (fig. 299) and some other Blaberidae 

 (e.g. Blaptica, fig.291). LIO is discussed in 6.3.4.. 



The muscles of this area have been investigated only in Parcoblatta and Blaberus. Muscle 

 15 of Anaplecta (fig.223) and Nahublattella (fig.251) is probably missing in Parcoblatta 

 and Blaberus or might possibly be incorporated into muscle 16b. Nahublattella (fig.251, 

 252), Parcoblatta (fig. 277-279), and Blaberus (fig. 305, 307) have some muscles in the 

 ventral wall of the left complex (130, 131, 132, 137, 138, 140, 144, 145), most of which are 

 rather diffuse. These can be homologised only in part, and the most probable homologies 

 are expressed by the designations. 



6.3. Left complex III: Main sclerites L4 and LIO and associated elements 

 6.3.1. Comparison between Blattaria and Mantodea 



The homology relations between Blattaria and Mantodea and the common ground-plan 

 can be best deduced from a comparison between Mantoida, Archiblatta, Eury-cotis, and 



