154 THE MEXICAN COTTON-BOLL WEEVIL. 



PARIS GREEN. 



One of the most important fallacies regarding a remedy for the boll 

 weevil was that which received great attention during the season of 

 1904, namely, that Paris green is a specific for the pest. The urgent 

 demand for a specific was evidenced by the very extensive use of this 

 substance. A portion of the great attention that it received pub- 

 licly was due to the fact that early in the season a certain number of 

 weevils may be killed by it. Applications made by spraying are even 

 less effective than dusting with the dry Paris green. As was pointed 

 out in Farmers' Bulletin No. 211, which deals with exhaustive field 

 and laboratory experiments with Paris green, the number so de- 

 stroyed in the spring really means nothing whatever to the crop 

 later in the season when the plants have put on squares and the 

 poison is no longer effective. As a matter of fact, the uselessness of 

 Paris green was quickly discovered by planters. Since 1904 prac- 

 tically none has been used in the warfare against the pest. (See 

 PI. XIX.) 



TRAPPING AT LIGHT. 



There is still, in many quarters in Texas and Louisiana, a supposi- 

 tion that it is possible to attract the boll weevil to lights. A number 

 of machines have been constructed based upon this idea. Whether 

 or not the boll weevil can be attracted to lights was one of the first 

 matters that was investigated by entomologists. During September, 

 1897, Mr. J. D. Mitchell, of Victoria, Tex., a naturalist and cotton 

 planter, set out trap lanterns in a cotton field in Victoria for one 

 night, and sent the insects captured to this bureau for examination. 

 In all, 24,492 specimens were taken, representing approximately 328 

 species. Divided according to habit, whether injurious or beneficial, 

 the result was: Injurious species, 13,113 specimens; beneficial spe- 

 cies, 8,262 specimens; of a negative character, 3,117. The interest- 

 ing point in connection with this experiment was the fact that not a 

 single specimen of the boll weevil was found, although the lights were 

 placed in the midst of fields where the insects were very abundant. 

 Since that time other investigators have looked into this matter fully. 

 Lights have been kept burning in cotton fields night after night for 

 several weeks. In no case has a single specimen of the boll weevil 

 been discovered, although thousands of species of insects have been 

 captured. 



The popular misapprehension about the possibility of capturing 

 the boll weevil at lights is due to the fact that somewhat similar 

 insects, Balaninus victoriensis, and other acorn weevils, differ from 

 the boll weevil in that lights exert a strong attraction for them. Dur- 

 ing occasional seasons the acorn weevils are exceedingly common in 

 Texas, and great numbers of them fly to the electric lights. 



OTHER PROPOSED REMEDIES. 



Hundreds of proposed remedies, in addition to those which have 

 been mentioned, have been carefully investigated. The claims of 

 their advocates in practically all cases are based upon faulty obser- 

 vations or careless experiments. The strong tendency of the weevil 

 to die in confinement, which has been referred to, has caused many 



