1964] 
Roth — Reproduction in Cockroaches 
209 
9 . 4 ± 0.2 
7.6 ± 0.2 
DAYS AFTER PARTURITION 
Fig. 8. Relationship between receptivity and subsequent oviposition, and 
the effect of mating following parturition on oviposition in N. cinerea. Top: 
Females that did or did not mate when exposed to males from time of, or 
<24 hr. after, parturition. (N = 57 for each group). Bottom: Females 
that were not mated after parturition. (N — 181). All females had 
mated previously only once, as virgins, prior to the first oviposition. 
Gestation period for all females ranged from 36 - 48 days. Arrows and 
numbers indicate the mean days ± standard errors to oviposit for each 
of the three groups. 
maining in the uteri for 3 - 10 days, the tubes were removed and the 
females were placed with males continuously. About 70% of the 
females treated in this manner eventually mated and these generally 
became receptive earlier than ovariectomized females that had not 
had artificial oothecae inserted (fig. 7). These results suggest that 
the prerequisites for the return of receptivity in the normal period 
of time in mated females are 1) the presence of an ootheca (uterine 
stretching) for at least a short time and then 2) the absence of the 
ootheca (removal of stretch stimuli). 
Receptivity of females after parturition , and the effect of mating on 
oocyte deevlopment 
Females of N. cinerea may or may not mate again after they give 
birth (Roth, 1962). If not mated after parturition, females averaged 
about 8 days to oviposit (fig. 8, bottom). The time required for 
