OVIPOSITION BEHAVIOR AND WATER CHANGES 
IN THE OOTHECAE OF LOPHOBLATTA BREVIS 
(BLATTARIA: B LATTE ELI DAE : PLECTOPTERINAE)* 
By Louis M. Roth 
Pioneering Research Laboratory, U. S. Army Natick Laboratories, 
Natick, Massachusetts 01760 
Oviposition behavior and changes in the water content of cock- 
roach oothecae during development of the eggs has been related to the 
evolution of ovoviviparity and viviparity in the Blattaria (Roth and 
Willis, 1955a, 1958; Roth, 1967a, 1967b). Based on the shape of 
water uptake curves, I suggested (1967a) that ovoviviparous cock- 
roaches (Blaberidae) may have evolved from blattellid-like ancestors 
whose oothecae 1) had low water contents (<50%) initially, 2) 
were carried externally until the eggs hatched, and 3) had S-shaped 
water uptake curves during embryogenesis. This stage in the evolu- 
tion of ovoviviparity was indicated with a query (Roth, 1967a, Fig. 
14) because no species was known to fit the category. At that time, 
the only forms known that carried their eggs externally for the 
entire embryogenetic period were species of Blattella , Chorisia fulvo- 
testacea Princis, and a third questionably identified genus (Roth, 
1967b) ; these are members of Blattellinae, genera of Blattellidae 
which rotate their oothecae 90° after they are formed. The oothecae 
of Blattella and Chorisia initially have a high water content (usually 
>56%), and do not have an S-shaped water uptake curve; I sug- 
gested that they could be placed more logically in the pathway for 
the evolution of viviparity than for that of ovoviviparity. 
Among the cockroaches I collected in the Amazon (see acknowl- 
edgements) was a female of Lophoblatta brevis Rehn. It was taken 
on a banana, plant in the town of Moura, on the Rio Negro, July 21, 
1967. The female was carrying an ootheca with the keel upright 
and the eggs hatched the day after the specimen was collected. The 
ootheca of Lophoblatta is not rotated and this plus other characters 
places this genus in the Plectopterinae of McKittrick (1964) ; it is 
the first plectopterine genus known which carries its ootheca until the 
eggs hatch. 
The ootheca of L. brevis is relatively thin, contains very few 
crystals of calcium oxalate, and the serrations of the keel are greatly 
reduced (Fig. 3). The egg case has an unusual shape ? being wider 
* Manuscript received by the editor March 20, 1968 
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