THE SUGAR-CANE MOTH BORER. 



31 



when the cane is cut, as the infestation increases up to this time and 

 as the examinations necessitate the removal of the leaves from the 

 stalk- — a rather undesirable proceeding when the plant has still to 

 make considerable growth. The plan adopted has been to examine 

 at least 100 stalks in a field, sometimes many more. The uninfested 

 and the infested stalks in these groups have been counted, and the 

 percentage of infestation is determined from the data thus obtained. 

 In actual practice this procedure has been modified. The number 

 of fields examined in one vicinity seldom has been less than four, 

 and often many more, depending upon the amount of time at the 

 disposal of the inspector. 



The infestation by the moth borer has been rather accurately 

 determined year by year for the six years 1912 to 1917, inclusive, 

 but the prevalence of other insect pests, which are not so important, 

 has been only estimated. 



To facilitate the inspections a card form was devised, which is 



reproduced here. 



Form of card for field notes. 





Sugar-cane Status, 



191.. 



.. State.. . 







. . . Plantation 



. . . Parish or county 





Group 

 examinations. 



1 



2 



3 



4 



5 



Total. 



Per 

 cent. 



Owner, 

 Location of field, 





Stalks. 

















Year of crop, 







Clean, 

















Variety, Soil, 





Diatraea, 

















Cultivation, 





















Sugar-cane condition, 





Joints, 

















Stalks cut? 



Stalks standing? Trash burned? 







Clean, 

















Aphis, Weevil, 





Diatraea, 

















Lachnosterna, Ligyrus, 1 





















Ants, Pseudococcus, 

























Remarks: 



Sugar-cane diseases, 



(A 







o 





Environment, 



'A 







i Ligyrus= Eucthcola rugiceps Le Conte. 

 AVEEAGE ANNUAL INFESTATION IN LOUISIANA. 



Observations have been made annually from 1912 to 1917, inclu- 

 sive, on the infestation of from 6 to 13 localities in the borer-infested 

 area of the Louisiana sugar-cane belt, with the result that the aver- 



