eee fee <a 
THE RED SPIDER ON COTTON. 67 
: pump earried through the field on a wagon or on a specially con- 
| structed vehicle of some sort. Figure 21, page 59, is from a photograph 
of a portable outfit devised by a progressive planter at Laurinburg, 
N.C., from suggestions supplied by the writers. It consists of a plat- 
form built upon the axle and shafts of a dismantled hayrake. The 
two wheels are large, bringing the axle well above the ground, so that 
injury of the plants is aorta to a great extent. A barrel pump 
| with a capacity of 50 gallons is mounted on the platform. A boy 
drives, one man pumps, and one handles each sprayer, of which pref- 
erably there should be two. Thorough treatment of 3 or 4 acres a 
day was readily obtained with this device. For safe work the attempt 
| should not be made to use this device in cotton of tall growth, since 
the passing wagon will injure high plants, but it is ideal in fields of 
average height or less. 
Some dissatisfaction has been experienced among certain of those 
who have undertaken to check the ravages of the red spider by 
“spraying. This can be understood on account of the extreme care 
which must be exercised in order to secure effective results. From 
the fact that the mite as a rule passes its entire existence upon the 
underside of a single leaf, it becomes plainly necessary in spraying to 
hit the entire underside of every leaf of an infested plant. Furthermore, 
since we have shown that no safe insecticide is known which will 
rad 
_ destroy red spider eggs, it is clear that a second spraying is necessary 
to kill the individuals which were eggs at the time of the first spraying. 
SUMMARY AND RECOMMENDATIONS. 
The common red spider occurs throughout the United States, but. 
“is known as a serious pest in only three regions, namely: In that 
' portion of the cotton belt including North Carolina, South Carolina, 
' Georgia, Florida, Alabania, and Mississippi, where it is primarily a 
' pest of cotton; in north-central and western Colorado as a pest of 
' fruit trees; and in central California, where the species is a rather 
_ serious pest of hop ficlds. 
It is estimated that during a season of severe red-spider occurrence 
the loss to the cotton planters of the Southeast amounts approxi- 
- mately to $2,000,000. 
From the records of the present investigation the common red 
spider is known to maintain itself successfully on 183 species of wild 
and cultivated plants, weeds, vines, bushes, and trees. A small 
number of these hosts show special attractiveness for the pest and 
infestation upon them reaches a more acute degree. These favorite 
species may be grouped as winter hosts and summer hosts, the former 
supporting the pest through the cold, inactive period of the year, and 
_ the latter furnishing food throughout the spring and summer. 
