THE PARASITES OF POPILLIA JAPONICA 33 
produced from eggs laid August 16 remained in the pupal stage until 
the following spring. From these fragmentary data it may be 
surmised that, under optimum conditions, a generation may be 
produced each six weeks, and that the number of generations per 
year will depend on the ability of the parasite females to find suitable 
grubs upon which to oviposit at all times during the season. 
CONDITIONS AFFECTING THE DEVELOPMENT OF CAMPSOMERIS IN AMERICA 
Since Campsomeris annulata is being introduced into America as a 
parasite of Popillia japonica, it is natural that consideration should be 
given to such factors as are likely to affect its development and in- 
crease there. The size of the adult wasp indicates that it is able to 
produce normal-sized progeny only upon Popillia grubs which have 
reached full maturity, and since these are not present in large numbers 
during the summer months, two courses of action are open to the 
parasite. One of these is to seek out some other host upon which to 
produce the midsummer generation, and the other is for the females 
to prolong adult life until suitable Popillia grubs become available in 
the fall. Both of these alternatives would result in decreased effec- 
tiveness against the major host as measured by the potential rate of 
increase, and although this may be unavoidable, the parasite may still 
be of considerable value in its early spring and late fall generations 
and in conjunction with the various species of Tiphia may contribute 
to the sum total accomplished by the grub pa/asites. 
TIPHIA POPILLIAVORA Rohwer 
GENERAL OBSERVATIONS 
Tiphia popilliavora (fig. 24), a parasite of Popillia grubs, was first 
found on August 20, 1920, at Koiwai in the identical place where C. 
cinerea, the tachinid parasite of adult beetles, had been located a 
week previously. Seven species of Tiphia were on the wing at that 
time and fed largely on the same blossoms. These species were 
successively tested upon grubs of P. japonica, and T. popilliavora 
was found to oviposit readily. Subsequent field observations proved 
the species to be restricted in this locality to the above host alone. 
Specimens were forwarded to the United States National Museum 
for examination and have been described by Kohwer as a new species 
under the above name. 
Investigations throughout the seasons of 1920-1923, inclusive, in 
the various parts of Japan have failed to reveal this scoliid in any 
abundance other than in the very restricted locality in which it was 
originally located. However, late in 1923 it was found to occur in 
small numbers at Suigen, Chosen. Here it was determined experi- 
mentally to be parasitic upon Popillia castanoptera and P. atrocoerulea, 
the former being the more common host. The major investigations 
and breeding work were confined to Koiwai entirely and covered the 
three years 1920 to 1922, inclusive. 
T. popilliavora is not of major importance in its native habitat, 
and at no time did the field parasitism exceed 20 per cent. The 
inability of the species to adapt itself to varying conditions, as evi- 
