OBSERVATIONS ON THE REPRODUCTION OF 
THE GIANT COCKROACH, 
BLABERUS CRANIIFERA BURM. 
By W. L. Nutting 
Biological Laboratories, Harvard University 
In his Embryology of the Viviparous Insects, H. R. Hagan 
(1951) cites nine species of roaches recorded as exhibiting 
some type of viviparity, or oviparity approaching vivi- 
parity. Chopard (1950) and Van Wyk (1952) have furn- 
ished two additional examples of viviparous blattids. Much 
of the evidence for viviparity has been indirect; that is, it 
has been based on dissections of gravid females, while in 
scarcely half the cases has the birth process actually been 
witnessed. Among the species mentioned by Hagan are 
the West Indian Blabera fusca Brunner (Saupe, 1929), and 
a Bolivian Blabera species (Holmgren, 1903). (Blabera 
fusca Brunner can probably be referred to craniifera Burm. 
according to Rehn and Hebard (1927).) Over the past 
seven years I have had the opportunity to observe rather 
closely a flourishing culture of Blaberus craniifera Burm., 
originally started from Florida specimens by Prof. C. T. 
Brues. (This roach is limited to Cuba in the West Indies 
and ranges from southern Mexico to British Honduras on 
the mainland; it has undoubtedly been introduced to Key 
West from Cuba.) During this period I have found newly 
hatched nymphs dozens of times, but only recently have I 
observed parturition itself. Before recounting this event, 
it seems appropriate to include available information on 
mating, the little-known spermatophore, and other relevant 
details on the reproductive habits of this large laboratory 
roach. 
Blaberus is rarely active during the daytime, even in the 
laboratory, and I have never seen courting behavior. How- 
ever, Saupe (1929) described the one case of love play and 
copulation for B. fusca which he observed during daylight. 
The actions were generally much like those detailed for 
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