1962] 
Roth and Stay — Cockroaches 
183 
2. Mating increases rate of oocyte development so that the first 
preoviposition period is less than in virgin females. Preovi- 
position period shortened on an average of about: 
a. 1 day (Pycnoscelus surinamensis, bisexual strain; Blattel- 
la). 
b. 9 or more days (Blaberus craniifer, Blaberus giganteus) . 
c. 17 days (Nauphoeta cinerea). 
d. 30 or more days (Leucophaea ?naderae). 
e. Majority of virgins do not oviposit for months or not at 
all. Oviposition occurs about 10 days after mating ( Di- 
pl optera punctata). 
3. Mating apparently has little effect on the rate of oocyte 
development but may stimulate oviposition (Byrsotria fumi- 
gata). 
4. Mating has no effect on rate of oocyte development or on the 
length of the preoviposition period (Pycnoscelus surinamensis 
— parthenogenetic strain mated to males of the bisexual 
form ) . 
II. Effect of mating on ovulation and oviposition. 
1. Ovulating virgins frequently retain mature oocytes in some 
part of the reproductive tract so that not all of the eggs are 
laid (Blaberus craniifer, Blattella vaga, Byrstotria fumigata, 
Leucophaea maderae , Nauphoeta cinerea, Pynoscelus surina- 
mensis bisexual strain). 
Mated females usually oviposit all of the mature oocytes. 
2. Ootheca is incompletely formed and oviposition is abnormal 
in a large percentage of virgins. 
a. Ootheca usually dropped when formed (Leucophaea ma- 
derae, Pycnoscelus surinamensis [bisexual strain], Blattel- 
la vaga). 
b. Ootheca dropped or partly retracted into the uterus (Nau- 
phoeta cinerea). 
c. Ootheca usually only partly retracted into the uterus so 
that some of the eggs protrude from the end of the ab- 
domen (Blaberus craniifer). 
Mating in a large percentage of females results in normal forma- 
tion of the ootheca and complete retraction of the egg case into 
the uterus in the above species. 
3. Ootheca may be retracted normally into the uterus in a high 
percentage of virgins (Byrsotria fumigata, Diploptera punc- 
tata, and Nauphoeta cinerea). 
4. Mating has no effect on normal oviposition ( Pycnoscelus 
