INSECTS INJURIOUS TO CORN. 30I 



have found suitable fields or suitable plants for their food, they alight 

 and crawl about, inserting their beaks through the tissues of the plant 

 and suck its sap. Chinch bugs in seeking their proper food plants in the 

 spring alight in immense numbers in our wheat fields. If the wheat 

 fields happen to be near a wood, or Osage orange hedge fence, or a wind 

 break, or a place where there is plenty of shelter, in which vast numbers 

 have hibernated during the winter, then, in this case, the chinch bugs 

 are very apt to come out from their winter quarters and crawl in vast 

 numbers to the wheat field. In such instances they are usually found 

 collected or massed together on the plants nearest the hibernating quar- 

 ters, and their presence will soon be detected by the effect that they have 

 upon the plants. It seems that chinch bugs, when they insert their little 

 beaks into the plants, involuntarily inject a little poison, which poison 

 causes an increased flow of sap to that place, and has more to do with 

 the injury to the plant than the amount of sap which the insect actually 

 extracts. A wheat field attacked in the way just mentioned will appear 

 bleached in the area or strip attacked. If left undisturbed, the chinch 

 bugs will gradually spread from plant to plant, so that the area of infesta- 

 tion will increase and move onward, gradually covering the entire field. 

 While a great many chinch bugs mate in the fall, the vast majority 

 of them mate in the spring soon after leaving their winter quarters, and 

 presently the females begin to deposit their eggs in the wheat fields and 

 grassy places, usually just below the surface of the ground under little 

 clods of earth about the roots and base of the plants. In about sixteen 

 days these eggs will begin to hatch, and presently the agriculturist will 

 detect the little yellow or reddish bugs in his wheat. In about six weeks 

 these insects will have reached the adult condition, and his wheat field 

 wil be literally over-run with chinch bugs. Meantime, the young bugs 

 have been drawing their nourishment from the wheat plants by sucking 

 the sap, and have done more or less damage, according to the number 

 of bugs in the field. Since each female lays upwards of five hundred 

 eggs, one can form an idea of the extent of the multiplication of these 

 insects since leaving their winter quarters. As the females take about 

 three weeks to deposit their eggs, and as these insects hatch according to 

 the weather, we find that new adult chinch bugs are appearing for three 

 weeks or more after the first ones have appeared. At about the time the 

 chinch bugs have become dangerously numerous in the wheat field, the 

 great bulk of them have become adults, and have done a great deal of 

 damage and the wheat plant has become ripened and no longer fit for 

 their food. The chinch bygs in such a field now take it into their little 

 heads to seek green pastures, and they usually do so all at once, and 



