WORK OF LOUISIANA CROP PEST COMMISSION. 123 



rest, seems to reduce the chance of any survivals in this area to one in 

 several thousand. 



Perhaps the most interesting point noticed in connection with this 

 extermination of the weevil by meteorogical conditions was the fact 

 that it was exterminated in Caddo, the northernmost parish of the 

 State, and also at Cameron, the southernmost point at which the 

 weevil has been found in Louisiana. As Cameron has about the 

 highest average winter temperature of any locality in Louisiana, and 

 as Caddo Parish has very nearly the lowest average winter tempera- 

 ture of any locality, it appears that the excessive moisture, rather 

 than low temperatures, was responsible for this heavy mortality. 



A similar loss of territory by the weevil in northern Texas has been 

 noted by Mr. Hunter and his assistants the present season (1905) ; 

 and so far as the writer is aware the winter of 1904-5 was the first 

 in which meteorological conditions brought about anywhere near so 

 great a decrease in the territory infested by this insect. 



In 1905 the migratory movement of the weevil commenced about 

 the middle of August and continued with more or less continuity 

 until about November 20. The existence of certain quarantines 

 throughout the State during August, September, and early October, 

 on account of yellow fever, prevented the extensive field observations 

 necessary to determine the exact time and extent of the migratory 

 movements. Field work could not be resumed until the middle of 

 October, and after that date an accurate survey was made to deter- 

 mine the eastern limit of the territory invaded. 



The migrations of 1905 gained for the boll weevil practically all of 

 the territory it lost during the winter, and a very considerable area in 

 addition. Cameron, La., a community practically isolated from 

 other cotton-growing sections by many miles of marsh, was the only 

 locality not reinfested by the 1905 migrations, careful field examina- 

 tions in this locality during December failing to reveal any indica- 

 tion of infestation. 



In the eastern part of the area at present infested (fig. 5) the 

 infestation is of course exceedingly light, maximum infestation and 

 consequent severe injury not occurring before the second season of 

 infestation and occasionally not before the third. In those por- 

 tions of the State reached by the weevil in the fall of 1903, or 

 the very early summer of 1904, the injury during the season just 

 passed has been considerable. Roughly outlined the area suffering- 

 severest weevil injury during 1905 is embraced in western Vernon 

 and Sabine parishes and southwestern De Soto Parish. In western 

 Sabine Parish the weevils are doubtless now as abundant as they ever 

 Avill be, and it is interesting to note, incidentally, that the farmers in 

 this section who have followed, even in a crude way, the cultural 

 measures advocated by the Bureau of Entomology and the crop pest 



