12 
Psyche 
[February 
The Puparium. Within a few hours of the time the mature 
larva quits the host, it burrows into the soil to a depth of one to 
two inches, and there pupates within the last larval skin, which 
forms the puparium. The pupa, then, falls in the first class as 
defined by Thompson (1910, p. 284), and probably has a rapid 
early development. Dissections of the puparia have not been 
made, and thus the appearance of the pupa and its rate of de- 
velopment are unknown. The pupal period of the spring genera- 
tion is approximately a month in length, while that of the summer 
generation lasts from thirteen to nineteen days. 
The Adult. The flies are able to take wing within a few 
seconds following emergence, and have been observed to mate 
within twenty-four hours. The length of time which then 
ensues before oviposition commences is not known, nor has the 
average number of eggs laid per female been determined. One 
fly laid thirty-nine eggs in twenty-four hours, and another, 
when captured in the field, contained over one hundred eggs. 
In the cages, honey-water on sponges failed to attract the 
flies. They were captured in the field from the flowers of Wild 
Carrot {Daucus carota) and Meadow Sweet {Spircea salicifolia) 
and would feed from these flowers in the cages. The writer did 
not learn of Townsend’s (1908, p. 110) method of feeding, using 
dry sugar and sponges moistened with water, until too late to 
use it in the breeding work. 
The behavior of caged females toward the bugs confined 
with them was interesting to observe. The urge to lay eggs did 
not appear to be constant. At times the flies would walk about 
among the bugs, with apparent friendliness, and would even 
crawl over them without making a menacing movement. At 
other times a fly would dart at a bug and alight upon its back, 
and the writer would focus his attention in the expectation that 
an egg would be laid. The fly would turn this way and that 
upon the unresponsive host, as if trying to decide where to place 
the egg, but after a few seconds would walk off, as if having 
changed its mind, leaving no egg behind. When oviposition 
actually took place, the act was accomplished with great rap- 
idity, the fly seeming scarcely to come to rest upon its host. 
That no such speed was necessary could be seen in the lack of 
