1910] Girault and Sanders — Chalcidoid Parasites Dag 
successfully parasitized, it having been partly opened at 3 P. M., 
May 13 and found to contain larval parasites. In this case the para- 
site was successful up to within about 24 hours of the final ecdysis, 
the host pupa being perfect and with all the colors of the mature adult. 
Case III. At 11:20 A. M., April 29, nine males and twenty females 
of the parasite, which had been freely mating, were confined together 
under a bell-jar with ten of the host puparia; oviposition was observed 
at noon and was continued with persistence until noon, May 3, when 
the observations had to be discontinued. During this time none of 
the hosts emerged, though in a control lot, emergence became general 
early on May 1, beginning during the morning of April 30. Hence 
in this case, the parasites being in greater numbers, not a single host 
escaped. 
Summarizing, parasitism by Nasonia is “ effective’ 
, 
or successful 
in many cases almost up to within the few hours immediately preced- 
ing the final ecdysis, depending on circumstances; a single female 
parasite, for example, would be able to kill a single host puparium up 
to within about 15 hours of eclosion, but where a number were present, 
many would escape before she would be able to deposit into them. 
And the converse is true. ‘The host when thus attacked is a perfect 
pupa and fully colored. 
O. Length of Life in Confinement; Adults. 
The adults of this parasite lived for about five days on the average 
in confinement, the males dying somewhat earlier. They were unfed 
in all cases. 
P. Change in Coloration of the Pupa. When first formed the pupae 
are yellowish white, the eyes garnet, with some duskiness at the caudal 
edges of the abdominal segments soon afterwards; the mandibles, 
legs, antennae and wing-pads gradually become dusky and about 48 
hours previous to eclosion, the head, thorax and abdomen, in succes- 
sion, begin to show dark color, the head and thorax together becoming 
a deep black before the abdomen shows very much color, and then 
after about 6 hours, the latter turns gradually but rapidly black. 
About 20 hours before eclosion, the color is jet black, which just 
preceding emergence changes nearly to the colors of the mature adult. 
At eclosion, the adults are fully colored. 
