244 



INSECT PESTS OF FARM, GARDEN AND ORCHARD 



rapidly in south Texas, ruining the crops, and by 1895 had spread 

 northward to a line extending eastward from San Antonio. 

 Since then it has spread northward and eastward, about sixty 

 miles a year, until in 1905 it had covered all of Texas and western 

 Louisiana and is now found almost throughout the cotton area 

 where weather conditions permit. 



In 1904, after an exhaustive study of all available data, the 

 writer estimated the loss in Texas alone at $25,000,000, and 



that the pest had then cost the 

 State $100,000,000. Owing to 

 decrease in acreage and the gen- 

 eral use of methods for preventing 

 or avoiding injury, the injury 

 has not increased proportion- 

 ately to the spread of the pest, 

 but the total annual loss is at 

 least as much as in 1904, though 

 no accurate estimates have been 

 recently made for the whole ter- 

 FIG. 207. The cotton boll weevil ritory affected 



enlarged. ^f e History. The parent in- 



sect is a small brownish beetle about one-quarter inch long, 

 varying from one-eighth to one-third, including the snout, which 

 is about half as long as the body. Recently emerged weevils 

 are light yellowish in color, but they soon become grayish- 

 brown and later almost blackish. There are many nearly related 

 weevils which very closely resemble the boll weevil, and only an 

 entomoligist can identify the species with certainty, but the two 

 teeth at the tip of the femora of the fore-legs (Fig. 207), are the 

 most characteristic structure by which it may be distinguished. 

 The boll weevil feeds only upon cotton, and weevils found feeding 

 on other plants are certainly of other species. 



However, there has recently been discovered in Arizona an 

 insect which very closely resembles the boll weevil and which has 

 been classed by authorities as merely a geographical variety 

 of the true boll weevil and named Anthonomus grandis thurberiae, 

 the Arizona wild cotton weevil, which feeds on a wild cotton 

 (Thurberia thespesioides) found growing in that region. This 



