232 
Psyche 
[September 
NOTES ON REPRODUCTION IN ASPIDIOTUS 
hederje (coccnxas). 
By Franz Schrader 
Bryn Mawr College, Bryn Mawr, Penna. 
Our present knowledge of the reproductive processes in 
the Diaspinse is a very limited one. The following observa- 
tions represent a rather cursory attack on this aspect of 
the biology of the oleander sc ale (Aspidiotus hederx) and 
in view of the lack of similar studies on this group of 
Coccidse no attempt is made to arrive at any final and 
concluding generalizations. 
The study had its inception in the very interesting paper 
of E. Gabritschevsky (’25) and so far as its more partic- 
ular purpose is concerned, hinges especially on Gabrits- 
chevsky’s statement regarding Aspidiotus hederx that “bi- 
sexual cultures live on the plant Aucuba japonica ; partheno- 
genetic or unisexually-female cultures grow best on a 
variety of palms. ” It will be seen that Gabritschevsky does 
not commit himself on a possible relationship between host 
plant and mode of reproduction and it is only fair to state 
that he was not primarily concerned with that aspect. 
Nevertheless, the possibility that there might be some co- 
relation between the type of host plant and the presence or 
absence of males induced me to investigate the species with 
this point in view. 
Parthenogenesis has been reported for various Diaspinse 
on several occasions. However so far as I know, no con- 
trolled experiments have been made to sustain these con- 
tentions and certainly the observed scarcity or absence of 
males in several instances is insufficient to establish the 
point. 
