THE GRAIN BUG. 23 



DATT.Y EATE 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 Qgg clusters are de- 

 posited by the same female on successive days. (See Table VII.) 



EELATION 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. 



PABTS 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 gTain 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 setae 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 OB 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 



