9 



and muscles, and with many distinct in- and evaginations of the cuticle (formative elements 

 such as processes, lobes, pouches, apodemes, or tendons). The structure as a whole is 

 always completely asymmetrical. Its morphology is quite variable within Mantodea 

 (LaGreca 1954) and extremely so within Blattaria (McKittrick 1964). In Isoptera the phal- 

 lomeres are said to be missing (Weidner 1970), a situation which is, according to Matsuda 

 (1976), an element of the neotenic traits generally observable within this taxon. 

 The phallomere morphology of Mantodea has been studied by Snodgrass (1937) in 

 Tenodera sinensis, by Levereault (1936, 1938) in Stagmomantis Carolina, and by 

 LaGreca & Rainone (1949) in Mantis religiosa. In each of these studies the cuticular 

 elements and the musculature are described. The three species are closely related 

 (Mantidae, Mantinae, Mantini in Beier 1968), and their phallomeres are rather similar. 

 LaGreca (1954) compared the cuticular elements of the phallomeres of several Mantodea. 

 In this selection all families of Beier (1968) are represented, except for those regarded as 

 most primitive: Chaeteessidae, Metallyticidae, and Mantoididae. 



Regarding the phallomeres of Blattaria, the paper of Snodgrass (1937) is the most 

 important of the earlier contributions. The sclerotisations and - in part - the musculature 

 of Periplaneta americana, Blatta orientalis (both: Blattidae, Blattinae). Blattella 

 germanica (Blattellidae, Blattellinae), and Ectobius lapponicus (Blattellidae, Ectobiinae) 

 are described. The phallomeres of Blattidae and Blattellidae are very different from each 

 other, and assumptions on homology relations are made only to a very small extent. 

 McKittrick (1964) investigated the phallomere sclerites in 24 genera of Blattaria and gives 

 a homology hypothesis. However, the descriptions are not very detailed, and the 

 musculature has not been studied. Thus, this homology hypothesis is not very convincing 

 in many points. McKittrick introduced a new terminology for the phallomere sclerites: 

 The terms are composed of several letters and numbers, each giving some information 

 about the position and the homology relations of the respective sclerite. McKittrick regards 

 the phallomeres of Cryptocercus (Cryptocercidae) as primitive within Blattaria. 

 Grandcolas (1994) studied the phallomere sclerites of Cryptocercus and some 

 Polyphaginae and Blattinae. He finds many synapomorphies for Cryptocercus and 

 (subgroups of) Polyphaginae and assigns Cryptocercus to Polyphaginae. However, the 

 homology relations assumed for the sclerites are disputable in many cases. 



Mizukubo & Hirashima (1987) studied the phallomere sclerites and muscles of Periplaneta 

 (various species; Blattinae), Blattella (various species; Blattellinae), and Opisthoplatia 

 orientalis (Blaberidae). They use - with some modifications - the terminology of 

 McKittrick. The authors homologise the phallomere sclerites according to their relative 

 positions and their mutual relations. Furthermore, they introduce a new topic into the 

 discussion: Homologies between elements of the left and of the right half of the phallomere 

 complex are considered. In their analysis they dismiss the musculature as a valuable 

 reference system for homologising. The phallomeres of the stem-species of Blattaria 

 (excluding Mantodea) are supposed to be still symmetrical. Accepting this view, the 

 asymmetry of the phallomere complex would have to be regarded as non-homologous in 

 Blattaria and Mantodea. In the case of Blattellidae and Blaberidae, which families show 

 obvious but side-reversed similarities in their phallomere morphology, Mizukubo & 



