32 BULLETIN 1429, U. S. DEPARTMENT OF AGRICULTURE 
the species, its habits, life history, etc., it appears probable that 
Anomala is the true host of the late generations, although Popillia 
serves equally well when present. 
LIFE HISTORY 
Since 0. annulata has been under observation for only a portion 
of one season, it is not possible at this time to present a complete 
account of its life history. In breeding experiments it was found 
that the methods used for Tiphia were not at all satisfactory, the 
females refusing to oviposit under the conditions provided. When 
placed in glass jars of about 1 -quart capacity, which had been nearly 
filled with well-packed soil, no difficulty was experienced. It appears 
necessary to provide these large breeding jars and to have the soil 
firmly packed in order that a well-defined cell may be formed by the 
grub, this latter apparently being necessary to the wasp at the time 
of oviposition. It appears also that the grub after being paralyzed 
is moved about in the soil to a considerable extent by the wasp before 
the egg is laid. In the field this behavior may be due to the need of 
the parasite to provide temperature and humidity conditions for 
her progeny more favorable than are present in the grub cell, which 
may be close to the surface and very dry. 
It has not thus far been possible to obtain oviposition under con- 
ditions which would permit of uninterrupted observation of the act, 
but stinging is probably accomplished in the same manner as by 
Tiphia. However, the paralysis effected is permanent rather than 
simply for the period required for oviposition, and consequently the 
paralyzed grubs could be placed in small depressions in moist soil 
and left without further attention until the formation of the cocoon. 
The egg is normally placed medially on the ventral surface of the 
third or fourth abdominal segment, standing perpendicularly, with 
the posterior end adhering lightly to the derm. The attachment is 
very insecure, aDd in case the host grub is imperfectly paralyzed 
is usually rubbed off by the slightest movement of the body. 
Hatching is effected by an irregular break in the chorion of the 
anterior end of the egg, and through this aperture the head and 
thoracic segments of the young larva emerge. The head is then 
lowered and the feeding puncture made on the median line of the 
next segment caudad. This feeding puncture is in reality a pro- 
nounced hole made in the derm, and is sufficiently large to permit 
the head to become completely buried within the body. An exuda- 
tion of the body fluids of the host takes place, and the "neck" of 
the larva is encircled by a quantity of this fluid external to the 
puncture. 
Molting occurs several times, and feeding continues at the same 
point throughout all the stages, after which the entire body contents 
are consumed. The cocoon is then spun, consisting of a dense mass 
of reddish-brown strands loosely woven together on the outer surface 
but compact within. It is not noticeably differentiated into layers, 
as is the case with that of Tiphia. 
The egg and larval stages prior to the formation of the cocoon 
cover periods of only 2 and 5 days, respectively, and the time passed 
within the cocoon only 33 days for the single male thus far reared. 
This, however, was under relatively low temperature conditions, and 
is doubtless considerably shortened during mid season. The females 
