1910] Girault and Sanders — Chalcidoid Parasites ' 15 
freshly emerged (average, 9 A. M., April 29) and of the same age, 
oviposition was begun at noon the same day and continued steadily 
until at least 9 P. M., May 2, 1909, when further observations were 
interrupted. These facts also hold for a single female of the same 
lot confined separately with 8 of the hosts. 
D. Time Elapsing between Emergence and Reproduction. Eleven 
adults of mixed sexes emerging from a single puparium of Phormia 
regina, from 11:45 A. M. to noon, Sept. 28, 1908, were at once confined 
together with four healthy puparia of the same host. At noon the 
following day oviposition was observed, or after a period of twenty- 
four hours. One pair of adults emerging at 8 A. M., Sept. 30, was 
confined immediately with seven healthy puparia of the same host; 
at 8:13 A. M. mating was observed and at 6:50 P. M. the same day 
the female was observed ovipositing; or after 10} hours. Mating 
in this instance followed almost immediately after emergence, and 
lasted for 14 seconds. In the case of the parents of the first spring 
generation of 1909, mating followed almost immediately after emer- 
gence and oviposition about 3 hours later. 
E. Duration of the Pupal Stage. This was obtained in one case 
only. A larva pupated during the night of Sept. 17-18, 1908, the 
newly formed pupa being yellowish white; by the twenty-first of the 
same month, the pupa had assumed nearly the colors of the adult, 
dark greenish, the head and thorax coloring first, the abdomen a 
few hours later. The resulting adult female emerged at 10 A. M., 
Sept. 23, 1908, making a pupal stage of approximately 53 days. The 
average length of this stage for the first spring generation (17 cases) 
was 9 days (May 14-23, 1909). 
F. Length of the Life Cycle. The few incidental observations 
obtained on this point are herewith given in tabular form. (Table IT, 
Bel.) 
Thus while the average daily effective temperature shows a gradual 
decrease, there seems to be no corresponding increase in the duration 
of the cycle. 
The duration of the cycle appeared to be somewhat longer in the 
case of the first spring generation, however, when the daily average 
effective temperature was low. Thus, hosts exposed to recently 
mated adults from noon, April 29, 1909, to late on May 2 —ovi- 
position continuing throughout that time — were filled with the 
nearly full-grown larvae of the parasite on May 13, pupation com- 
