April, '17] KELLY: GREEN-BUG OUTBREAK 245 



on this date as many as thirty brown aphids could be found on a leaf, 

 but brown aphids could be found only in the immediate vicinity of the 

 small area where we had placed them. Again we searched thoroughly 

 for parasitized aphids in other parts of the fields, and none were found. 

 The Toxoptera were increasing in vast numbers and large numbers of 

 winged forms were coming into the field. The plants were three and 

 four leaved, as against one and two leaved on the 29th of April, with 

 every leaf heavily infested and reddening. This being a warm day, the 

 adult parasites were issuing from the brown aphids brought up from 

 Medford, but not from those on the plants. Whether we had intro- 

 duced enough parasites in any of these fields to overcome the heavy 

 infestation seemed to be doubtful; they seemed to be gaining no head- 

 way, while the Toxoptera were gaining by great strides. Many of the 

 oat fields were from 85 per cent to 100 per cent infested, the plants 

 turning reddish-brown everywhere. Mr. Parks could not remain with 

 me for the next day, so a drive of about one hundred miles to the north 

 was made alone. I observed the Toxoptera to be very abundant in all 

 the oat and wheat fields, to a line just south of Wichita, this line being 

 the southern border of a rain which occurred on the 30th of April. 

 North of Wichita to Newton very few Toxoptera could be found. 

 Returning west of Wichita through Goddard I found the same condi- 

 tions. Immediately south of the Santa Fe Railroad I began to find oat 

 fields which were heavily infested. 



On the 9th of May, it was decided that we had not made sufficient 

 introduction of the parasites to be fully satisfactory, and upon the 

 request of Dr. Hunter and Mr. Hungerford, we decided that we would 

 return to Medford, secure more parasites, and try for further introduc- 

 tion. The fields were now becoming very heavily infested ever}^ where 

 from Wichita south to El Reno, Oklahoma. Our observations en 

 route from Wellington to Medford indicated that all of the wheat fields 

 and all of the oat fields were heavily infested; oats having the appear- 

 ance of having been swept by fire, much of it being totally destroyed, 

 and wheat suffering severely. The conditions were more and more 

 appalling as we neared Medford. We secured several soap boxes full 

 of infested plants containing several hundred thousand of the para- 

 sites, from the field one-half mile northwest of Medford. These were 

 brought to Wellington and released in the fields, where we had not put 

 parasites on former dates. However, preceding the introduction, 

 Messrs. Wellhouse, Lawson, Barrett, Scott, and I investigated the 

 fields; we found a few parasites. About two hundred thousand para- 

 sites were liberated in each of two oat fields immediately west of town. 

 The adult parasites were numerous in the boxes, issuing en route; these 

 began ovipositing immediately upon being released. 



