June 15,1921 
Anastatus semiflavidus 
333 
resistant to adverse weather conditions as a pupa than as a dormant 
larva or as an adult, and it would appear that the pupal period is made 
as short as possible in order to hurry the insect through the most vul¬ 
nerable period of its existence. The few pupae dissected from para¬ 
sitized eggs have invariably been found during periods of heavy adult 
emergence. 
NUMBER OF INDIVIDUALS PRODUCED BY EACH FEMALE 
In cage experiments, two females under observation produced 60 and 
54 individuals, respectively (Tables I and II). These figures may be 
considered as being below the average, because under natural conditions 
each female probably produces a greater number of progeny than when 
confined in cages. 
JUMPING HABIT OF ADULTS 
Although equipped with wings, the adults of both sexes appear to 
lack the power of sustained flight. Locomotion seems to be accomplished 
largely by means of jumping or running. Adults that were observed in 
the field running around on the ground in the vicinity of host egg clusters 
disappeared with startling rapidity when an attempt was made to collect 
them, their movements, when approached, resembling those of the 
halticine flea-beetles. This ability to jump made the species very 
difficult to handle in the laboratory cages, and many adults were lost 
during the process of feeding or when they were being transferred from 
one cage to another. 
The males are much more active than the females. 
RELATIVE PROPORTION OF SEXES 
From a quantity of Hemileuca oliviae eggs collected in the field a total 
393 adults issued. Of this number 158 were males and 235 were 
females. From two series of life-history cages a total of 423 adults 
issued. Of this number 175 were males and 248 were females. These 
figures would seem to indicate that both sexes were well represented but 
that the females were slightly more abundant than the males. (Tables 
I and II.) 
POSITIVELY PHOTOTROPIC HABIT OF ADULTS 
fhe adults of Anastatus semiflavidus are positively phototropic. This 
characteristic was used to advantage in rearing the adults from eggs 
collected in the field and in handling the species in life-history cages. 
HOSTS OTHER THAN HEMILEUCA OLIVIAE 
Adults of Anastatus semiflavidus were reared from eggs of Hemileuca 
nevadensis Stretch, collected from willow along the banks of the Red 
River in New Mexico. Laboratory experiments also demonstrated that 
