1964] 
Roth — Reproduction in Cockroaches 
239 
allata since these endocrines remain inactive in most virgin females 
and the oocytes fail to develop (Engelmann, 1959; Roth and Stay, 
1961). 
The influence of mating and nutrition on oocyte development in 
most females during the first and second preoviposition periods is 
compared and summarized in table 13. If females of L. maderae 
are starved during the first preoviposition, their oocytes fail to 
develop even if the individuals are mated. In virgin N. cinerea the 
oocytes develop only slightly if the females are starved but mating 
results in sufficient stimulation (via the brain) of the corpora allata 
so that the oocytes mature in about the same time as fed-mated 
controls. In fed females of both species, mating and feeding stimuli 
act synergistically to activate the corpora allata to their fullest extent 
so that the oocytes mature at their maximum rate (Roth, 1964). 
After parturition, the oocytes in normally fed individuals of N. 
cinerea and L. maderae mature rapidly and mating does not increase 
the rate of maturation. The effect of starvation following parturition, 
in females fed during gestation, differs between the 2 species. In 
N. cinerea the oocytes mature rapidly even though the females are 
starved and not mated again. In marked contrast, the oocytes of 
L. maderae are inhibited after parturition if the females are starved 
and an additional mating does not affect this inhibition. In N. 
cinerea mating has a stimulating effect on oocyte development if 
females are starved during gestation and are then given food for 
2 and 3 days only, after parturition (table 10). However, mating 
has no effect if the females starved during gestation continue to be 
starved, or are given food for only one day after giving birth. 
These results are in accord with the hypothesis (Roth, 1964) that 
mating stimuli are effective in further stimulating the corpora allata 
only if the corpora allata have reached a certain level of activity, 
or if activating stimuli to the corpora allata have begun to occur 
as a result of nutritional factors. This hypothesis also would explain 
the results obtained when oothecae were removed from the uteri at 
different periods of gestation and the females were then starved 
(table 11). 
The corpora allata of cockroaches which incubate their eggs inter- 
nally are inhibited during pregnancy and the oocytes increase only in 
length and usually yolk is not deposited (Roth and Stay, 1962b). 
However, in Diploptera punctata (Eschscholtz) (Engelmann, 1959; 
Roth and Stay, 1961) and N. cinerea (Roth and Stay, 1962b), the 
corpora allata may become active a few days before parturition and 
