Circular No. 1 52. Iaraed July 10, 1912. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY. 

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



THE RICE WATER-WEEYIL AND METHODS FOR ITS 



CONTROL. 



(IAssorhoptrus simplex Say.) 



By E. S. Tucker, 

 Entomological Assistant. 



ECONOMIC IMPORTANCE. 



The most serious insect enemy of growing rice in the Southern 

 States is the rice water-weevil (LissorTwptrus simplex Say) (fig. 1). 

 When in its larval stage, the insect is known to rice growers as the 

 " rice root-maggot." The larvae feed on the roots of rice plants, and 

 the adult weevils cause some harm by feeding on rice leaves. 



Owing to the extensive growing of rice in sections of Louisiana, 

 Texas, and Arkansas within recent }^ears, the weevil has found very 

 favorable conditions in the rice fields for its multiplication in propor- 

 tion to the increase of the acreage and to the number of years in 

 which rice has been grown in any section. The development of 

 definite rice-growing areas in these States has naturally resulted in 

 particular centers of high infestation by the weevil. Rice growing 

 has consequently been attended hy great damage to the crops on 

 account of the insect's attacks. 



The amount of loss that is occasioned by the attacks is difficult to 

 estimate, as the reduction of yield has been variously reckoned in 

 different localities. Since all fields are not affected alike and differ- 

 ent portions or spots of a field are apt to suffer the severest injuries, 

 although the plants seldom fail outright, the growers differ much 

 in their opinions of the extent of damage which they sustain, but all 

 agree in the declaration that it is considerable. General statements 

 of the shortage of production include a report by a grower at Beau- 

 mont, Tex., who placed his loss as low as 1 per cent; but the attacks 

 in some fields at Stuttgart. Ark., have been severe enough to cut 

 down the yield as much as 75 per cent. 



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