94 



the middle of the day from 10 or 11 o'clock until 3 or -1 in the after- 

 noon, the bugs sheltering themselves meantime against the heat as 

 best they can. As night approaches they become quiet again, and 

 they make no migration movements after twilight falls. 



The Arrest of the Outbreak en 1915 



Effect of tin Weather. — Whatever uncertainty may attach to our 

 judgments of the principal causes of the origin and continuance of our 

 chinch-bug uprising, there can be none as to those of its suppression 

 in 1915. as will be seen from the following narrative abstracted from 

 the notes of Mr. W. P. Flint, in charge of my field operations during 

 that year. 



Examinations of chinch-bugs in their winter quarters during the 

 latter part of March. 1915. and counts of living and dead bugs, showed 

 that only a very small percentage of them had died during the winter. 

 Thruout the greater part of the infested area they were active in their 

 places of hibernation during the warm days from the 5th to the 9th 

 of April, but few or none flew into wheat fields at this time. During a 

 second warm period, beginning April 16. a general flight into the 

 fields began, and by the 25th of that month nearly all the bugs were in 

 the wheat or the oats. 



Eggs were very abundant in the wheat by April 28 in the central 

 part of the infested area, and by the first week in May in the northern 

 part also, but owing to cool and rainy weather, beginning in most sec- 

 tions about May 3. their hatching was much delayed. Fifteen collec- 

 tions of the eggs brought in from the field before May 11 hatched, on 

 an average, twenty-eight and a half days thereafter, and some not 

 until forty-three days after they were brought in. 



Young bugs were first noticed in the fields May 17. but they were 

 not at all abundant until the end of May. From May 20 to 30 very 

 hard beating rains fell over the whole infested area. At Springfield 

 the total rainfall from May 25 to 27 was 6.26 inches, and it was nearly 

 as great at several other places. These rains caused the death of 

 most of the adult chinch-bugs in that part of the infested area. Dead 



cape from the stubble fields surrounded by tarriers was ordinarily made until 

 aiDOut the middle of the forenoon. More detailed data are as follows: 



"July IS. 1912. The morning bright and very clear; temperature at 5:30 

 a. m.. 66 degrees, no movement of the bugs; 6 a. m., temperature 65.5 degrees, no 

 movement ; 7 a. m.. temperature 74 degrees, slight movement among such of the 

 chinch-bugs as were directly exposed to the rays of the sun: 7:30 a. m.. tempera- 

 ture 75 degrees, slight general movement in field and in post-hole traps, but no 

 bugs crawling to the road-oil line. July 19. Morning bright and clear: tempera- 

 ture. 5:30 a. m., 61 degrees F.. no movement: 6 a. in., 64 degrees, no movement: 

 7 a. in., 70 degrees, no movement; 7:30 a. m.. 76 degrees, slight movement among 

 the bugs, altho no real effort was made to leave the field. 



According to afternoon observations, recorded in Bulletin 191 of the Kan- 

 sas Agricultural Experiment Station, it appears that in the dry cloudless weather 

 of 1911 and 1912 "the bugs usually began to escape about 4 p. m.. reaching the 

 maximum from 5 to 5 : 30, and usually ending by 7 p. m. ' ' 



