THE PARASITES OF POPILLIA JAPONICA 
21 
METHODS OF HEARING AND COLLECTING FOR SHIPMENT 
Considerable difficulty was experienced in breeding this parasite 
because of the extreme nervousness of the field-collected females 
under laboratory conditions, resulting in very early death, and the 
fact that larvae were produced rather than eggs. Under normal 
conditions the young larvae are deposited on the surface of the soil 
and they then burrow about in search of host grubs, into which they 
penetrate very quickly. 
An examination of gravid females revealed the ovarian sac as 
containing upward of 800 eggs and larvae, the number of the latter 
being variable, ranging from 50 to 300, and located in the terminal 
Fig. IS. — Prosena siberita. female 
portion of the sac (fig. 19). When the wall of this sac was broken 
with a scalpel or needle the young larvae were immediately liberated 
and quickly crawled away. Experiments indicated that larvae 
obtained in this way were normal in every respect and were able to 
penetrate the host and to develop without difficulty. This brought 
up the possibility of the use of this method in breeding work, the 
larvae to be transferred to the host by means of a fine brush. Kesults 
were very satisfactory, and practically 100 per cent effectiveness was 
obtained from these inoculations. At first the half-grown host grubs 
were placed in individual vials of one-half inch diameter and five or 
six Prosena larvae placed upon each, the vials then being filled with 
