2 BULLETIN 746, U. S. DEPARTMENT OF AGRICULTURE. 



Linnaeus, that it is grown from cuttings which are laid lengthwise 

 in the rows, that it grows from late spring through the warm months 

 of the year, and that it must be cut before it is damaged seriously 

 by cold weather. 



The plant does not produce seeds in Louisiana, though it does in 

 tropical countries and, occasionally in southern Florida and the 

 southern tip of Texas. The stalks are cut in the fall, the leafy tops 

 and side leaves are trimmed off and left on the fields, and the stalks 

 are ground in the mill, this being the first step in the manufacture 

 of sugar. The leaves and tops left on the ground usually are called 

 the " trash," but by some " shucks," and by others " flags." 



The principal insect injurious to sugar cane in the United States 

 is a moth generally known in the larva stage as " the borer," but 

 it is distinguished from other boring insects of sugar cane by the 

 names " moth borer " and " lesser moth borer." It is a member of 

 the order Lepidoptera, family Pyralidae and subfamily Crambinae, 

 and has the scientific name Diatraea saccharalis Fabricius, variety 

 erambidoidcs Grote. It is this insect which is considered in the 

 following pages. 



CHARACTER OF INJURY TO SUGAR CANE. 



The work of many insects is apparent immediately, even to the 

 untrained observer, but the injury due to the sugar-cane moth borer, 

 familiarly known as the "borer," is the more serious for the reason 

 that it is not noticeable except on close examination. To the casual 

 observer one field of sugar cane is like many others. If the leaves 

 are pulled away from a stalk, however, a few holes may be observed 

 in the rind and perhaps a quantity of sawdustlike material may 

 be seen clinging to the stalk. This is evidence that the moth borer 

 has been at work. If the stalk is split lengthwise, tunnels about an 

 eighth of an inch wide may be found running for several feet, 

 several tunnels sometimes joining in such a way that the plant is 

 greatly weakened and is easily blown down by a high wind. 



It is evident that such injury must occasion various forms of 



loss, in tonnage of cane, pounds of manufactured sugar, etc. The 



injury is rendered even more serious by the insidious habits of the 



insect, since the full amount of damage is underestimated by the 



average planter. Only by walking through the field and examining 



stalk after stalk can any definite idea of the full amount of injury 



be obtained. 



ESTIMATE OF LOSSES. 



Not only are the mature canes injured greatly by the moth borer, 

 but many young plants, especially in the early summer, are killed. 

 (See " Effect on young cane — ; dead hearts,' " p. 5.) As many as 100 



