376 
Journal of Agricultural Research 
Vol. XXI, No. 6 
partly developed larvae within their host. This theory would account 
for the presence of the fully developed larvae that are frequently found 
within their host eggs early in the succeeding spring. 
IyARVAL, PERIOD 
Periodic dissections and emergence records of egg clusters that had 
been exposed to adults in confinement indicated extreme variations in 
the duration of the larval period for different individuals. 
From a series of isolated host egg clusters that had been exposed to 
parasite adults in cages for two days during the last week of September, 
1914, a few adults emerged early in May, 1915. The larval period of 
these individuals therefore was limited to about seven months, whereas 
some of the other eggs in these same egg clusters were found to contain 
full-grown dormant larvae nearly two years later—that is to say, in March, 
1917 - 
Dissections of 1- and 2-year-old eggs collected in the field gave similar 
results and established the fact that on some occasions the insect remains 
in a dormant larval state for at least two years. 
It will be apparent from the foregoing that any statement concerning 
the duration of the larval period must necessarily be in approximate 
terms. 
pupae period 
The pupal period is evidently very short, as in a long series of dissec¬ 
tions of parasitized eggs, made at intervals of three or four days, it was 
observed that pupae were rarely found, although many of these eggs 
contained fully developed larvae and adults were emerging each day. 
Pupae were dissected out of the host and placed in different types of 
cages in an attempt to ascertain the length of the pupal period, but 
none were reared through to the adult form. 
, ADUI/f period 
In laboratory experiments the females remained alive for several 
weeks in Doten cages that were supplied with equal parts of honey and 
water as food. Under these same conditions the males remained alive 
but a few days after being placed in the cages. 
Adults have been observed in the field from the early part of May until 
the first of December, the maximum emergence occurring during July 
and August. As the host eggs are not deposited until September, it is 
probable that the females live for long periods under field conditions, 
the length of their life depending upon the proximity of their host and 
upon the weather conditions. 
DURATION OP EIPE CYCEE 
From a series of 49 cages started in September and October, 1914, a 
total of 383 adults were reared. These adults required a maximum of 
