10 
BULLETIN 1429, U. S. DEPARTMENT OF AGRICULTURE 
represent an additional percentage of the total. To illustrate this 
point, the graph representing the parasitism of female beetles at 
Koiwai during 1921 (fig. 8) may be cited. On July 14, 35 per cent 
bore eggs, these being replaced on the 20th by 45 per cent of the 
remainder, the latter in turn being replaced by 48.5 per cent of those 
<st//iy 
^<?<i/&tAS7- 
<30 
20 
■7 
/2 /3 /* /S /S /7 /<9 /S 2& 2/ 22 23 2* 2S SOT 27 2& 2? 30 3/" / 2 3 * S & 7 <ff 
c 
k 
3 
^* 
Fig. 8.— Curves showing the percentage of parasitism of Popillia japonica by Centetcr cinerea 
at Koiwai, Japan, during 1921: A, parasitism of female beetles; B, parasitism of male 
beetles; C, proportion of eggs laid upon female beetles 
remaining on the 26th. Thus, theoretically, the parasitism effected 
was 35 plus 29 plus 17 per cent, successively, during the period of 
abundance, totaling approximately 81 per cent of the entire infesta- 
tion. The actual host mortality, however, was lower than this 
figure, since the mortality in the early stages of the parasite has not 
been taken into account. 
Fig/9.— Popillia parasitized by Centeter, in process of packing for shipment to the United States, 1923 
COLLECTION AND SHIPMENT 
Very extensive collections (fig. 9) of parasitized beetles were made 
at Sapporo and Koiwai in 1921 and at the former place only in the 
following two years. Two hundred and ninety-six thousand were se- 
cured during this period. As many as 200 men, women, and children 
