Fourth Annual report. 



9 



established at a very early date in the season in order to secure the best re- 

 sults. As a rule, the agents in charge of the substations reported that where 

 the experimenters carefully followed the directions successful results were 

 obtained. It is too often the case that the experimenter departs from the 

 letter of his instructions at almost every point, and charges failure to some 

 defect in the character of the infection. Persistent effort in carrying out 

 the details of the method is as essential to success in field experiments for 

 the destruction of the chinch bug as in any other legitimate agricultural 

 enterprise. 



5. — Field Experiments Conducted by Central Station. 



During the season of 1894, for the first time since the beginning of our 

 experiments, the chinch bugs have attacked fields in the immediate vicinity 

 of our laboratory. This gave us the first opportunity of conducting an ex- 

 periment which could be under our own personal supervision from begin- 

 ning to end. Inasmuch as this may be taken as a standard example of the 

 manner in which the Sporotrichum works in the field, I will append the fol- 

 lowing notes. 





The field experimented upon was a cornfield 100 rods in length, a por- 

 tion of which joined the University campus, and the remainder a wheat 

 field, from which the wheat was cut on June 20. When the wheat was cut 

 it was noticed for the first time that chinch bugs were abundant in the 

 wheat. They moved immediately from the wheat field into the adjacent 

 cornfield, belonging to another owner. The bugs were first noticed by him 

 in the corn in large force, in both A and B, blackening the stalks, on Sat 

 urday, June 23. The bugs were in about 20 rows in field A, and about 10 

 rows in field B. A strip of potatoes between corn in field B and the wheat 

 field had hindered the bugs in their progress into B. The contents of one 

 of the laboratory boxes of the 24 by 36 by 6 inches dimension was taken 



