2 BULLETIN 416, U. S. DEPARTMENT OF AGRICULTURE. 
W. B. Parker, H. E. Ewing, and others, as well as the writers, have | 
established the presence of the red spider from Maine to Florida 
and westward to Texas, California, and the Hawaiian Islands. It 
is said to be generally distributed in New England, New York, Iowa, 
Qlinois, the southern parts of Wisconsin and Michigan, western 
Colorado, the Willamette Valley of Oregon, and the interior regions 
and southern part of California. . 
® ZONAL DISTRIBUTION IN THE SOUTHEAST. 
In the course of our work on ‘distribution it early became evident — 
that the majority of the occurrences in the Southeast were confined 
to a zone the outer margin of which hes from 60 to 80 miles from the 
Fic. 1.—Distribution of the common red spider. Large dots represent specific occurrences; dotted 
line incloses the zone of heaviest occurrence in the Southeast. (Original.) 
coast and whose inner margin is from 200 miles (along the Atlantic 
coast) to 275 miles (along the Gulf coast) inland (fig. 1). In general 
this zone coincides with the portion of the Piedmont Plateau possess- 
ing clay or sandy loam soil and excludes the coastal strip of sandy 
soil. The infested area includes the central belt of oak, hickory, and 
longleaf pine hills, the sandhills belt, and the granite and meta- 
morphic gray and red lands. The coastal free area includes the 
marshes, swamps, and live-oak lands of the coast and the longleaf 
pine flats and savannas near the coast. Whether this restricted dis- 
tribution is due to the diversity of plant life or to the differences in 
climatic conditions prevailing in the respective regions it is diffi- 
cult to determine. Considering the great adaptability of the red 
spider to hosts, it would appear that the matter of the host flora 
must be one of minor influence. The material difference in humidity, 
