6 



FARMERS BULLETIN 831. 



its boundaries the occurrence was general. 'W'liile such a case as this 

 is unusual, 4-acre or 5-acre spots with 25 to 100 per cent damage 

 are frec|uently seen. 



During one season (1912) about 20,000 acres of cotton in South 

 Carolina were seriously infested by the red spider. Since the yield 

 thus lost is about two-fifths of a normal crop on this area, or 2,716,000 

 pounds, it will be seen that at 1 2 cents per pound this lost lint repre- 

 sented a tax of S325,920. The cotton seed lost, at 1912 prices 

 amounting to $67,900, brought the total levy on the South Carolina 



planters to about 

 $393,820. In view of 

 the fact that North 

 Carolina, Georgia, 

 Alabama, and Missis- 

 sippi suffer similarly 

 and are each consid- 

 erably larger than 

 South Carolma, it is 

 estimated that during 

 a severe red-spider 

 year the Southeast 

 may suffer a loss of 

 $2,000,000 from the 

 ravages of this pest. 



DESCRIPTION OF THE 

 RED SPIDER. 



Both male and fe- 

 male red spiders are 

 present on the plants. 

 The color of the fe- 

 males is subject to 

 considerable varia- 

 tion. At times it is 

 rusty green, some- 

 times greenish amber, 

 occasionally yellowish, at times ahnost black, but most often brick 

 red, and a large spot of much darker color is usually seen along the 

 back half of each side of the body. The males are considerably 

 smaller than the females, more pomted behind, of a rusty sahiion 

 color, and the spots at the sides are not conspicuous. The red spider 

 is in reality not a spider but a mite, and is more nearly related to 

 the ticks than to the true spiders. As is usual with mites,%oth the 

 male and the female have eight legs, but no wings. The females are 

 less than one-fiftieth of an inch in length. 



Fig. 3.— An uninfested cotton plant, growing in same field shown 

 in figure 6, but just beyond the boundary of infestation by the 

 red spider. 



