﻿30 BULLETIN 1374, TJ. S, DEPARTMEISTT OF AGEICULTUEE 



Table 23. — Infestation of plantings in 1921 distance-of-flight tests 



Point 



No.l 

 No. 2 

 No. 3 

 No. 4 

 No. 5 

 No. 6 

 No. 7 

 No. 8 



Dis- 

 tance 

 from 

 fields 



Date first bloom Date foimd infested 



Miles 

 1 



2 I 

 3 



July 19 to 28 I Aug. 25-_. .„ 



Jiily 13 ' Sept. 22 



Aug. 18 to 25 Sept. 15 



do Sept. 1 



Sept. 1 to 7 ■ Sept. 7 



July 28 to Aug. 4._ Oct. 14 



Aug. 18 to 25 Sept. 7 



July 6 to 13 I July 28 and Sept. 29 



Larvae per group of plants- 



First Second 

 instar instar 



Third 

 instar 



Fourth 

 instar 



Total 



Date 

 plants 



were 

 de- 

 stroyed 



Aug. 30 

 Sept. 22 

 Sept. 18 

 Sept. 7 

 Sept. 8 

 Oct. 14 

 Sept. 8 

 Oct. 2 



All the groups of plants became infested, No. 8, which was 8 miles 

 from the nearest cotton field, being the first. As only one small 

 larva was fomid in this instance it was removed; but the plants were 

 not destroyed. Close examinations showed that there was no con- 

 nection between this infestation and the later one in this group of 

 plants. In all other cases the plants were removed soon after the 

 infestation was discovered, and all forms closely, examined, with the 

 results given in the table. Each group of plants in this test became 

 infested independently of the others, with the nearest source of infes- 

 tation as indicated in the table. Whether the moth reached any or 

 all of the points by flight or through carriage by man can not be 

 explained. There was no occasion of infested material being carried 

 past these plantings but the moth may have been carried out in mak- 

 ing inspections or by carts which occasionally passed near by. Still, 

 with rnillions of moths in the fields, it would not seem strange had 

 some of them been carried to these plantings by favorable winds, 

 even though their power of flight is limited. 



The following season (1922) plantings of small groups of plants 

 were made in several directions from the source of infestation. Table 

 24 shows the arrangement of these plantings and the results obtained. 



Table 24. — Results in distance-of-Jiight plantings, Tlahualilo, 1922 



Point 



Distance 

 from 

 cotton 



Direction 



Infestation 



Remarks 



No. 1 



Miles 

 5 

 8 

 5 

 8 

 5 

 6 



North 







No. 2 



do 



West 







No. 3 



Early 





No. 4 



.. do . - . 









East . 



do 



Do. 



No. 6 



do 



do - 



Do. 











With the exception of the failure of the plants at point No. 1 to 

 become infested, the results are about the same as in 1921. 



In addition, two other plantings were made in 1922, one 25 miles 

 northwest and the other 40 miles west of the nearest cotton in the 

 Laguna district. These plantings were on cattle ranches and con- 

 sisted of about 100 plants each. The first showed as heavy an 

 infestation at the end of August as the average for the Tlahualilo 



