382 
Journal of Agricultural Research 
Vol. XXI, No. 6 
examination, however, reveals the presence of the sealed ovi- 
position puncture, and this is the only external indication by which a 
parasitized egg may be recognized. The parasite can not be discerned, 
even during its advanced stages, through the opaque, thick-walled shell 
of the egg. This appearance is in marked contrast to that of eggs of 
the gypsy nioth ( Porthetria dispar L.) which have been parasitized by 
Anastatus bifasciatus Fonsc. The parasite larva of this closely allied 
species is plainly visible through the shell of its host egg. 
Hemileuca oliviae larvae frequently hatch from eggs bearing oviposition 
punctures of the parasite. This is probably due to the fact that these 
particular eggs were not successfully parasitized. 
appearance of host eggs from which aduets have emerged 
The adult, upon emerging from the pupa, finds itself completely inclosed 
within the walls of the host egg. It gnaws a small but easily distin¬ 
guishable hole through this wall and makes its escape. 
The host eggs from which Anastatus semifiavidus adults have issued 
may be readily recognized by the presence of this exit hole. It is much 
smaller than the hole made by the hatching of the host larvse. (PI. 68, C.) 
method of earvae deveeopment 
The larva of Anastatus semifiavidus prevents the formation of the 
embryonic larva of its host and feeds exclusively upon the liquid contents 
of the host egg. This method of larval development is characteristic 
of the true egg parasites. 
dormant period of fuee-grown earva 
After the larva has become full-grown, the development of the pupal 
stage depends largely upon the external climatic conditions to which 
the egg is subjected. In northern New Mexico, these climatic conditions 
refer especially to humidity and must be considered in this special sense. 
The degree of humidity as affecting the development of parasite larvae in 
this semiarid climate depends largely upon whether the eggs are situated 
on high or low ground, or upon the distance from areas of surface water. 
If the parasitized egg, containing a full-grown larva, happens to be 
subjected to a long period of drought, pupation may be delayed and a 
dormant larval period of indefinite duration produced until such a time 
as both humidity and temperature are favorable for further development. 
When these favorable conditions occur, the full-grown dormant larva 
changes to a pupa without regard to the length of time spent in the 
larval stage. 
SHORT EENGTH OF PUPAE PERIOD 
The duration of the pupal period is very short, as noted by numerous 
dissections. From this fact it is assumed that the insect must be less 
