RED SPIDER ON COTTON AND HOW TO CONTROL IT. 5 



DISTRIBUTION IN THE SOUTHEAST. 



The common red spider is very generally distributed in the United 

 States. The map (fig. 2), which contains 297 records of occurrence 

 in 34 States, shows the distribution of the majority of reported cases. 



The majority of the occurrences in the Southeast are confined to 

 a zone the outer margin of which lies from 60 to 80 miles from the 

 coast, while the inner margin is from 200 miles (along the Atlantic 

 coast) to 275 miles (along the Gulf coast) hiland (fig. 2). 



EXTENT OF INJURY. 



I^nlike many pests, the red spider does not occur continuously 

 o\^er large areas. Certain fields are infested while many others are 

 free. Large fields are probably never damaged throughout, but 

 smaller fields frequently become wholly affected. A thorough exam- 

 ination of all fields within 1 mile of the center of Leesville, S. C, was 

 made during the height of the season with a view to determining 

 the exact state of rod-spider mfestation m one locality. In all, 99 

 fields were exammed as carefully as possible and about three-fourths 

 of them wei'e found to be infested. This occurrence was one of the 

 severest and most general that has at any time come to the writer's 

 attention. The worst infestation m the above-mentioned locality 

 was one which spread from its point of origin until it extended in 

 one direction 600 feet from the original source. (See fig. 6.) The area 

 finally affected, semicircular in shape, comprised 13 acres, and within 



Tig. 2.— Distribution of the common reJ spider. Dots represent specific occurrences; dotted line 

 incloses the zone of heaviest occurrence in the Southeast. (McGregor and McDonough.) 



