Circular No. 171. issued March 21, 1913. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY. 

 L. O. HOWARD, Entomologist and Chief of Bureau. 



FIELD OBSERVATIONS ON SUGAR-CANE INSECTS IN 

 THE UNITED STATES IN 1912. 



By T. E. HoLLOWAY, 

 Entomological Assistant. 



INTRODUCTION. 



The results here presented are based on tlie records of field observa- 

 tions made during the year 1912. Though the information on any 

 one insect is fragmentary at best, it has been thought desirable to 

 issue this report for the reason that so Httle is definitely known con- 

 cemmg insects affecting sugar cane in the United States that even a 

 very incomplete treatment of the subject is a contribution to the cur- 

 rent knowledge. 



A survey of the sugar-cane areas of Louisiana and Texas was under- 

 taken during the year, and tliis work has been supplemented by some 

 observations made in Mississippi and Alabama. In subsequent 

 reports more attention will be given to the States last mentioned, as 

 well as to Georgia and Florida, but the press of other work in the past 

 has rendered it impossible to give these States the attention they 

 deserve. 



Credit and the thanks of the writer are due to Mi'. E. R. Barber, of 

 this bureau, for making a number of field examinations, mainly the 

 final observations in northern Louisiana and those in IMississippi and 

 Alabama. 



THE SUGAR-CANE MOTH BORER. 



(Diatrsea saccharalis Fab.) 



Special attention was given to the determination of the percentage 

 of infestation of the moth borer, tliis being the prmcipal insect inju- 

 rious to sugar cane in tliis country. The plan adopted was to examine 

 125 stalks of sugar cane in a field, choosing the stalks in 5 different 

 groups of 25 stalks each. The uninfested and the infested stalks in 

 these groups were counted, and the percentage of infestation was 

 determined from tliis data. In actiud practice this proceeding was 

 changed to some extent. More than 125 stalks were sometimes 



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