THE RICE WATER-WEEVIL. 6 



The recent work of the bureau on the rice water-weevil was begun 

 in 1910 by Mr. C. E. Hood, working under the direction of Mr. D. L. 

 Van Dine. The present writer began work on the problem in 1911. 

 In this circular many notes made by Mr. Hood are incorporated. 



The object of this paper is to give as much practical information 

 as is now available about the weevil and measures for its control in 

 order that rice growers may make proper efforts in fighting the pest 

 and secure larger crops. The cooperative facilities afforded by the 

 Agricultural Experiment Station of Louisiana, through Prof. W. R. 

 Dodson, director, in providing accommodations at the State Rice 

 Station, Crowley, La., and allowing free use of the unpublished notes 

 comprising a preliminary investigation of the rice water-weevil by 

 Mr. TVilmon Newell, in 1909, deserve grateful acknowledgment. 



HISTORICAL ACCOUNT AND DISTRIBUTION. 



The weevil was originally described in 1831 as Bagous simpler 

 by Thomas Say. It and another species of weevil were given the 

 generic name of Lissorhoptrus by Dr. J. L. LeConte in 1876. Le- 

 Conte and Horn have stated that the weevil commonly inhabits 

 swampy places throughout the eastern part of the United States. 

 Its northern range extends into the Lower Peninsula of Michigan, 

 according to Hubbard and Schwarz, and Dury has recorded the spe- 

 cies as being taken near Cincinnati, Ohio. It is also reported from 

 Xew Jersey. Maryland, and the District of Columbia. Mr. E. A. 

 Schwarz has concluded " that the genus Lissorhoptrus occurs all along 

 the Atlantic coast (including the Gulf of Mexico), recurs along the 

 Great Lakes, and is occasionally found inland." 



As an injurious insect, the species first attracted the attention of 

 rice farmers along the Savannah River in Georgia and South Caro- 

 lina. In 1881 Dr. L. O. Howard visited a rice plantation known as 

 " Proctor's," and owned by Col. John Screven, on the South Carolina 

 side of the river, a short distance below Savannah, Ga., for the pur- 

 pose of studying the insects affecting rice crops. An account of his 

 observations, including notes on the rice water-weevil, was published 

 in the report of the United States Commissioner of Agriculture for 

 1881 and 1882. But little advance has been made in further knowl- 

 edge of rice-crop insects up to the present investigation. 



DESCRIPTIONS OF STAGES. 



The adult. — The mature insect is a small, dark-gray weevil (fig. 

 1, g). The technical description by Mr. E. A. Schwarz in the account 

 above mentioned is here quoted : 



Lissorhoptrus simpler. — Imago: Average length from tip of thorax, 3 mm. 

 Oblong-oval, covered with large, dirt-colored scales, but usually entirely en- 



