259 



bl-muscles are only present in Mantodea: Sphodwmcintis (fig. 15. 16), Mantoidci (fig. 43). 

 Muscle b5 of Nahublattella (fig.235, 259, 261) and the muscles b6 (fig.294, 316) and b7 

 (fig.317) of Blaberus are certainly apomorphic muscles of these species. 



6.9. The phallomero-sternal muscles 



Phallomero-stemal muscles inserted on the right half of the subgenital plate have even 

 numbers, those inserted on the left half have odd numbers. The insertions on the subgenital 

 plate are designated as ventral, those on the phallomere complex or on the walls of the 

 genital pouch as dorsal. The anterior margin of the subgenital plate is the whole margin 

 between the right and left contacts between the subgenital plate and the paratergites of 

 segment 9 (compare fig.333a). Fig. 333 gives an overview and a homology hypothesis for 

 the phallomero-stemal musculature of the species studied. 



Mantoida has 6 phallomero-stemal muscles sl-s6, whose ventral and dorsal insertions are 

 arranged almost symmetrically (fig.40, 333b). In my view, this is the most primitive 

 situation within the species studied, and it is taken as the basis for the terminology, si 

 and s2, s3 and s4, as well as s5 and s6 are assumed to be pairs of primitively symmetrical 

 muscles. Thus, three pairs of primary muscles will be distinguished, which in the 

 primitive situation have the following basic arrangement: 



-si and s2 insert on the median anterior margin of the subgenital plate and run to the 

 ventral basal line of the left complex or right phallomere, where they insert more 

 laterally. 



- s3 and s4 insert on the median anterior part of the subgenital plate, closely behind si 

 and s2, and run to the ventral basal line of the left complex or right phallomere where 

 they insert more medially than si and s2. 



- s5 and s6 insert on the lateral anterior margin of the subgenital plate and run to the 

 lateral or lateroventral walls of the genital pouch. 



Within this basic arrangement, the dorsal insertion of s2 and s4 is on the anterior margin 

 of sclerite R3, that of si is on anteriormost parts of L4-sclerotisations (anterior L41- 

 region), and that of s3 is on a membranous part of the basal line. 



The evolution of the phallomero-sternal musculature comprises two kinds of development: 

 (1) The morphology of the 6 primary muscles changes by subdivision, fusion, shift, or 

 loss. The exact homology relations are often difficult to determine. (2) New secondary 

 muscles develop, each with a characteristic course by which the homology relations can 

 in most cases easily be determined. These secondary muscles are: 



- s7 inserts on the median anterior part of the left side of the subgenital plate and runs 

 to the anterior part of the Ive-pouch. 



- s8 inserts on the median anterior part of the right side of the subgenital plate and mns 

 to the top of the tre-tendon. 



- slO inserts on the median anterior part of the right side of the subgenital plate and mns 

 to the ejaculatory duct or to an area near its opening. 



- sl2 inserts on the median (or more lateral) anterior part of the right side of the subgenital 



