16 DEPARTMENT BULLETIN 179. 
DURATION OF LIFE WITHOUT FOOD. 
The life of the adult is very short when deprived of food during its 
period of normal activity in summer temperatures. Five pairs of 
adults confined without food under a daily maximum temperature of 
75° to 85° F. began dying on the second day and all were dead at the 
end of the fifth day. Under the same circumstances five pairs of 
adults kept under a daily maximum temperature 15° lower began 
dying on the fifth day and all were dead at the end of the ninth day. 
During hibernation the body of the adult contains much fatty tissuc 
which apparently acts as a reserve food supply. 
SEASONAL DEVELOPMENT. 
SEASONAL HISTORY. 
In the latitude of northeastern New Mexico the adults of Chloro- 
chroa sayi emerge from hibernation during the first warm days of 
late April or early May. At this time the ovaries of the females con- 
tain fully developed eggs, and if mild weather conditions prevail 
these eggs are deposited within a few days on the underside of the 
rubbish or other material composing the hibernating quarters. 
The resulting nymphs feed and develop upon the young sprouts 
of Russian thistle or other plants which have developed early in the 
season under the protection of the accumulated rubbish. Upon reach- 
ing maturity, about the last week in June, the adults of this first gen- 
eration and the survivors of the overwintering brood migrate to the 
fields of grain and feed upon the tender stems and developing heads 
until the grain ripens. It is during this period that most of the 
economic loss from the grain bug occurs. The females of this gen- 
eration usually deposit their eggs on the underside of rubbish in the 
field, or on Russian thistle growing along the ditches, fence rows, or 
waste areas. Occasionally eggs are deposited on different parts of 
the host plant, notably the awns or beards of the head, but as a rule 
the female seems to prefer the underside of some object near the 
ground. The newly hatched nymphs from these eggs have not been 
observed to feed upon the cultivated crops, but apparently depend 
upon weeds, especially Russian thistle, for their sustenance until 
reaching the third or fourth instar. 
The second generation is completed about the same time that the 
majority of the grain crops are harvested, during the first week in 
August. The surviving adults and large nymphs of the first two 
generations then migrate to fields of late grain, milo maize, Sudan 
grass, volunteer grain, or other food plants which then are developing 
heads. If none of these crops is present, the insects confine their 
feeding to any of the native food plants growing in the vicinity. 
Se 
