1968] 
Roth — Oothecae of Lophoblatta 
IOI 
sp. B , Fig. 78). Perhaps, a closer study of Lophoblatta may reveal 
sufficient differences in species like L. brevis to warrant placing 
them (or the others) in different genera. 
The dorso-ventral flattening of the ootheca of L. brevis and L. 
arlei (see below) may have adaptive significance in that it would 
allow the female to rest or crawl into more narrow spaces and re- 
duce the chances of losing the oothecae prematurely, than if the egg 
cases were of the usual shape (i.e., taller than wide) and carried 
with the long axes of the eggs in the vertical position. Females of 
Blattella germanica (L.) that carry the ootheca in a horizontal posi- 
tion could crawl into a space which averaged 0.4 of a mm. narrower 
than females that were still carrying the egg case perpendicularly 
(i.e., before rotation) (Wille, 1920). The adaptive value of rota- 
tion in the Blattellinae may well be to allow the female to crawl 
into narrow crevices while carrying its ootheca, and also to reduce 
the chances of the egg case being knocked off accidentally while 
crawling in these narrow spaces. In the ovoviviparous Blaberidae, 
rotation of the ootheca reorients the eggs so that their long axes 
lay in the plane of the cockroach’s width and would thus allow for 
growth of the eggs by stretching the uterus, principally in a lateral 
direction, in insects that are usually quite flat (Roth, 1967b). The 
significance of rotation of the ootheca in the oviparous Blattellidae 
differs from its importance in the ovoviviparous and viviparous Blab- 
eridae, but its occurrence in oviparous forms preadapted them for the 
evolution of species which incubated their eggs internally. 
A colony of L. brevis was established from the female collected in 
Moura, and from another female in Puraquequera, Rio Negro, July 
31, 1967. Water determinations were made on oothecae of different 
ages (removed from females at various times after oviposition). The 
results are shown in Fig. 7. The initial water content of the ootheca 
is about 36%. Little change in this percentage takes place until about 
the ninth day. A marked increase in water content occurs between 
days 9 and 1 1 , followed by a more gradual rise in percentage of 
water until just before the eggs hatch, at which time it reaches about 
75 %• The water uptake curve is S-shaped as was predicted (Roth, 
1967a) and compares well with other plectopterines that drop their 
oothecae after forming them and which have <50% water at the 
time of oviposition (see Roth, 1967a, Fig. 3). The shape of the 
water uptake curve also is very similar to that of the ovoviviparous 
cockroach Nauphoeta cinerea (Olivier) (see Roth, 1967a, Fig. 8). 
The ootheca of L. brevis is carried for 31 to 34 days (Figs. 9, 10) 
and after the eggs hatch a new eggcase is formed 9 to 10 days later. 
