6 THE BOLL WEEVIL PROBLEM. 
infested area. During the first 10 years after its advent into this 
country the annual rate of spread was 5,640 square miles. Since 
1901 the annual increase in the infested territory has averaged 
26,880 square miles, but in one exceptional season, namely, 1904, 
51,500 square miles became infested. Of course, the figures given 
do not refer to the area in cotton. In many parts of the infested 
territory the area devoted to cotton is much less than 10 per cent of 
the total area. 
The territory in the United States in which the boll weevil was 
found to occur at the end of the year 1911 is shown in figure 1. This 
territory included the southeastern half of the cotton section of 
Texas, the southeastern corner of Oklahoma, the southern three- 
fourths of Arkansas, all of Louisiana, the southern three-fourths of 
Mississippi, the southwestern corner of Alabama, and the extreme 
western portion of Florida. Outside of the United States the boll 
weevil is known throughout the larger portion of Mexico and south-. 
ward to Guatemala and Costa Rica. It is also known to occur in 
about one-half of Cuba. 
DAMAGE. 
The damage done by the boll weevil varies greatly from year to 
vear and also in different parts of the infested area. As the rainfall 
increases the damage becomes greater. In prairie regions, where the 
insect obtains but little protection through the winter, it never be- 
comes so numerous as in other quarters where favorable conditions 
for hibernation are found. These facts, together with variations due 
to winter conditions, make it rather difficult to estimate the exact 
damage that has been done. Some years ago the writer stated, from 
the statistics then available, that the weevil caused a reduction of at 
least 50 per cent of the cotton crop in regions invaded by it, but that 
after the first few years the farmers generally resorted to proper 
means greatly to reduce this loss. In many individual cases the 
means of control perfected by the Bureau of Entomology have been 
applied so successfully that the crop has been fully as large as be- 
fore the coming of the weevil. This was not accomplished, however, 
without somewhat increasing the cost of production. The estimate 
of an initial falling off in production of 50 per cent was verified by 
Prof. EK. D. Sanderson, formerly State entomologist of Texas, who 
arrived at his figures in an entirely different way. 
The average yield per acre in Texas from 1893 to 1901 (when the 
weevil had not done damage sufficient to affect the general produc- 
tion) was 0.40 bale. The average since that time, 1902 to 1911, was 
0.34 bale. By comparing these periods we have a reasonably accurate 
basis for estimating the damage the insect has done. The difference 
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