210 
Psyche 
[December 
oviposition by females which did or did not mate when exposed to 
males after parturition is shown in figure 8 (top). Females which 
mated oviposited later than those that did not mate, indicating that 
the females which were receptive afer parturition had comparatively 
smaller oocytes (see below) and therefore took longer to oviposit 
than the unmated females. This apparent lack of stimulation of 
mating differs from that produced by mating during the first pre- 
oviposition period where firm insertion of the spermatophore results 
in an increase in the rate of development of the oocytes (Roth, 
1964). 
In L. maderae , mating after parturition also does not accelerate 
oocyte maturation (Engelmann, 1960a). Leucophaea maderae differs 
from N. cinerea in that the time taken to oviposit after parturition 
in females that do or do not mate is essentially the same; 14.5 ± 0.5 
days and 15.4 ± 0.3 for mated and unmated females respectively 
(table 9), whereas N. cinerea females that do not mate oviposit 
sooner than mated females. The difference between these species 
apparently is due to the fact that in L. maderae the corpora allata 
are inhibited during the entire gestation period and the oocytes of 
females at parturition are more or less the same size and do not 
contain yolk (see fig. 7 in Roth and Stay, 1962b) ; in N. cinerea 
the oocytes at parturition may vary considerably in size (figs. 1, 6). 
At high (26°-28°C.), fairly constant insectary temperatures, the 
number of N. cinerea which have yolk in the oocytes at or prior to 
parturition was greater than females maintained at usually lower, 
markedly fluctuating, room temperatures (fig. 9, bottom). Females 
which become receptive after parturition generally mate within 24 
hr. Figure 9 (top) shows the lengths of the oocytes about 24 hr. 
after parturition of females that did and did not mate when they 
had access to males. The females with comparatively small oocytes 
Table 2 — Relationship between length of gestation period and receptivity 
following parturition in N. cinerea 
Gestation period (days) 
Number used and 
percent mating* 
N 
% 
35 - 36.5 
28 
79 
37 - 38.5 
69 
75 
39 - 40.5 
31 
36 
41 - 42.5 
28 
11 
43 - 44.5 
36 
19 
45 - 46.5 
16 
25 
47 - 50 
13 
0 
* Females kept with males until they mated or oviposited. 
