1969] 
Roth — Genitalia of Blattaria 
219 
Results and Discussion 
The male genitalia of Blaberidae consist of 3 main structures 
( McKittrick’s, 1964 terminology). The right phallomere (R2) 
(Figs. 1-12) is a retractable hook, and all the species have a sub- 
apical incision (Fig. 2, arrow). The median sclerite (L2vm) is 
solidly attached (in Blaberus spp.) to L2d (L2 dorsal = the virga, 
penis, or aedeagus) (Fig. 52). The prepuce (mantle of Hebard’s, 
1917 terminology) is a soft, flexible membrane (Fig. 52) bearing 
characteristic spines, or truncate or rounded sclerotized elevations. 
The left side of the prepuce is solidly attached by sclerotization to 
the side of the L2 phallomere, whereas the right side is usually 
connected by a flexible membrane which permits it to fold partly 
around the virga. One of the sclerites (Li) (Figs. 13-24) of the 
left phallomere in all the species of Blaberus studied are more or 
less similar and have a heavily sclerotized cleft, noted by McKittrick 
(1964). 
Based on body size, color, and shape of the pronotum, Hebard 
( I 93 I ) placed fusiformis, brasilianus , anisitsi, and scutatus in the 
Brasilianus Group of the genus. Princis ( 1946) divided 8 species into 
the Giganteus and Atropos Groups, basing his divisions on the shape 
of L2d and the spines present on the prepuce. He did not examine the 
genitalia of minor , brasilianus , fusiformis , and scutatus , but suggested 
that the Brasilianus Group, established by Hebard, probably should be 
included in the Atropos Group. As a result of my examination of 
the 4 species not investigated by Princis, I believe Hebard was 
correct in erecting the Brasilianus Group and I place the above 4 
species in this group. 
Species of Blaberus can be readily placed in their respective Groups, 
by the shape of the virga and preputial spines. However, variation 
is such that specific determination is often difficult. The 3 Blaberus 
Groups may be distinguished in the following key: 
1. L2d recurved dorsally and slightly to the right, usually forming 
a hooklike structure (Fig. 52). Extending dorsally and later- 
ally on the left, about where L2vm and L2d are solidly joined, 
is a sclerotized tumorlike outgrowth (Fig, 52, T). There are 
no large truncate elevations and all of the spines on the prepu- 
tial membrane are relatively small (Figs. 28-40, 47-57, 62-74, 
215) Giganteus Group. 
L2d not hookshaped. Tumorlike outgrowth on the left side ab- 
sent. Prepuce with anterior truncate or rounded elevations 
almost always present on the left, and sometimes on the right 
side of the preputial membrane 2. 
