fourth Annual Report. 11 



July. From two to three gross of infection boxes are filled with Sporo. from 

 this field daily. The bugs, both old and young, seem to be but sparingly 

 present in the field. Here and there a very few live bugs may be found in 

 the axils of the leaves and under clods. 



July 13. — The Sporo. is continually increasing in the field, but there is a 

 larger number of live bugs on the corn in places than could be seen on the 

 9th. 



July 16. — There was a heavy rain on the 15th. There are plenty of 

 sporo. bugs for picking, and pickers are still at work, and have not ceased 

 since they began, on the 5th. 



July 18. — Sporo. is increasing all over the field, but the bugs are numer- 

 ous in occasional spots throughout the field. These bugs are of all ages, 

 but adults greatly predominate. The dead bugs or mummies gathered by 

 the pickers now include large numbers of little red bugs as well as the 

 pupae and the adults. 



July 22. — A visit to the field shows the live bugs reduced to a satisfac- 

 tory minimum ; probably not more than 1 to 2 per cent, remain of the num- 

 ber which blackened the stalks for from two to three feet above the ground 

 for 20 rows when the infection was first introduced. The entire field prom- 

 ises an abundant crop of corn, and even the outer rows, where the attack 

 was most severe, are well eared and luxuriant in foliage. 



From this field the pickers had already gathered 7,000 boxes, and might 

 have gathered 25,000, of Sporotrichum-cowered bugs, as a reserve stock for 

 early distribution to the farmers for use in the wheat fields in the spring of 

 1895. If in every township in the state of Kansas infested with chinch 

 bugs a similar gathering should be made by the township trustees, and dis- 

 tributed to the farmers early in the spring, the chinch bug would soon be 

 reduced to an uninjurious minimum. 



6. — The Method of Infection. 



The method of infecting chinch bugs with Sporotrichnm globuliferum in 

 the laboratory and in the field during last year was essentially the same as 

 the method described in our last report, with the exception of a few details. 

 Clean, friable garden soil was used in the boxes to maintain the proper hu- 

 midity, instead of excelsior, leaves, etc., as formerly.. All substances liable 

 to decay were excluded, and the green wheat and corn used were removed 

 as soon as they turned yellow. Even with these precautions, the odor of 

 ammonia, due probably to the decay of the bugs, could be detected in the 

 boxes. Sporotrichnm does not flourish under such conditions, and whenever 

 the odor of ammonia was detected the boxes were cleaned out and lei't ex- 

 posed to dry air for a day or two, and then started anew. The soil was 

 spread over the bottom of the boxes to the depth of about an inch, and 

 kept moist and friable, but never allowed to become muddy. 



Dead bugs covered with Sporotrichnm are found at all depths in the soil 



