9 FARMERS’ BULLETIN 135. 
In severe cases the dropping of the leaves is sufficient to prevent 
the development of lint. The loss of foliage, however, is always 
accompanied by the shedding of bolls, which may amount to the total 
loss of fruit or merely of the younger bolls. On the plants other 
than cotton, which the red spider often attacks, the appearance of 
the injury is similar to that on cotton, although it is unusual for 
most plants to show the red blotching. The feeding is done by 
means of sharp, slender, lance-like mouth parts which are thrust 
well into the leaf, usually on the under surface. 
Injury results from the extraction by the red spiders of the juices 
of the plant leaves. It is plain, therefore, that the mites can not be 
killed by poisons sprayed onto the leaves, 
| | which may be devoured in feeding, but 
\ y must be attacked by sprays which kill by 
\, \ HH] y contact. 
Y} // EXTENT OF INJURY. 
Sh Ui sd, tT Unlike many pests the red spider does 
AX | not occur continuously over large areas. 
Ts 3 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 examination of all fields 
i \ \ within 1 mile of the center of Leesville, 
A /\ 
\ S. C., was made during the height of the 
season with a view to determining the 
fi i exact state of red-spider infestation in 
| ; one locality. In all, 99 fields were ex- 
| amined as carefully as possible and about 
| three-fourths of them were found to be 
media a ott mates ee infested. This occurrence was one of the 
chus telarius: Adult female, Severest and most general that has at any 
oe enlarged. (From  tjme come to the writer’s attention. The 
, worst infestation in the above-mentioned 
locality was one which spread from its point of origin until it ex- 
tended in one direction 600 feet from the original source. (See 
fig. 5.) The area finally affected, semicircular in shape, comprised 
13 acres, and within its boundaries the occurrence was general. 
While such a case as this is unusual, 4-acre or 5-acre spots with 25 to 
100 per cent damage are frequently seen. 
During 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 12 cents per pound this lost lint represented a 
