12 BULLETIN 233, U. S. DEPARTMENT OF AGRICULTURE. 



they attack cotton. Many of the habits of the Thurberia weevil are 

 adapted to the activities of these plants and to the higher altitudes at 

 which they live, and it is questionable just how readily and to what 

 extent it will adapt itself to cotton. But since the species has shown 

 such great adaptiveness in the Southern States, it is to be feared that 

 the Arizona form will do the same. At any rate, it is an ever-present 

 menace to cotton cultivation in the Santa Cruz Valley and should be 

 watched most carefully. It is quite probable that with a more inti- 

 mate knowledge of the extent of the weevil distribution in the State 

 it will be possible to establish, local quarantines of seed-cotton ship- 

 ments which will at least keep the weevils out of the localities which 

 do not have the species present in nature. In the Southern States 

 cotton cultivation is of course very general and there the weevil ad- 

 vances each season by flying, but in Arizona, where the different 

 areas suitable for cultivation are separated by considerable stretches 

 of mountainous country, such a means of dispersion would only be 

 possible within very limited areas. Consequently it should be possi- 

 ble to keep the weevil entirely out of areas not within range of direct 

 infestation from nature. 



In addition to the watch for infestation by native weevils, the dan- 

 ger of importation of the weevil from the Southern States should be 

 remembered, and all efforts should be made to validate the quaran- 

 tine against this variety. 



* SUMMARY. 



1. A weevil very closely related to the Mexican cotton-boll weevil 

 exists on a wild cotton plant in some of the mountains of southeastern 

 Arizona. 



2. The species seems to be particularly concentrated in the ranges 

 surrounding Tucson. 



3. This weevil may transfer its attack from the wild cotton plant 

 to the cultivated cotton in the Santa Cruz and Rillito Valleys at an 

 early date. 



4. Its present habits are such that it would not injure cotton 

 greatly, but these habits will probably be changed to a certain ex- 

 tent and more injurious ones acquired. 



5. The present habits render it quite probable that' the control of 

 the Arizona form will be a very different problem from that of the 

 cotton weevil and more easily solved. 



6. A careful watch should be maintained for the first appearance 

 of the weevil on cultivated cotton in order that it may be combated 

 successfully. 



WASHINGTON : GOVERNMENT PRINTING OFFICE ; 1915 



