THE GRAIN BUG. Die 
DAILY RATE OF OVIPOSITION. 
The daily rate of oviposition varies considerably with individual 
females of the same age confined in life-history cages under identical 
conditions of food and environment. 
Normally several days elapse between the deposition of each egg 
cluster, but occasionally a female deposits several small egg clusters 
on the same day, and frequently one or more egg clusters are de- 
posited by the same female on successive days. (See Table VII.) 
RELATION OF TEMPERATURE TO OVIPOSITION. 
The amount of oviposition in the field is not noticeably affected by 
the ordinary ranges of summer temperatures, because many of the 
egg clusters are deposited by the females when they are in hiding 
during the cool periods of the day or during inclement weather. 
Probably, however, the greater percentage of the eggs is deposited 
during the warmer parts of clear days when the females are actively 
feeding. 
FEEDING. 
PARTS OF PLANTS PREFERRED. 
The grain bug exhibits a marked preference for the juices of the 
seeds and fruits of its food plants and apparently feeds upon the 
tender stems and leaves only when more favored portions of the 
plants can not be obtained. | 
In grain fields the feeding is confined to medium sized and 
rapidly growing heads of immature seed. After the grain reaches 
the “dough” stage the insect ceases to feed upon it. Whether it 
does so because it prefers other food, or because the hardening of the 
glume containing the seed prevents the entrance of the setz which 
constitute its piercing mouth parts, is not known. 
METHOD OF ATTACK. 
The adults attack and damage their food plants in much the same 
manner as has been previously described for the nymphs. The 
selected portion of the plant is pierced and its liquid contents re- 
moved by suction. The adults are very active in searching for the 
fruit or seeds of their food plants, and the total amount of damage 
caused by the insect in this stage is much greater than during the 
nymphal period. 
CONSPICUOUS APPEARANCE WHEN FEEDING OR RESTING. 
The grain bug adults are very conspicuous objects in the field, 
owing to their large size and tendency to seek the upper part of each 
plant, when feeding or resting on the grain heads. On clear days 
