RED SPIDER ON COTTON AND HOW TO CONTROL IT. 9 



of September there is a reduction iii the numbers of the red spider, 

 and this reduction contmucs as the weatlier becomes colder, until 

 by the end of November the low point is agam reached. Hot, dry, 

 conditions, such as occur during times of drought, hasten develop- 

 ment, while cool, wet weather retards it. A female laymg normally 

 about 6 eggs a day will, upon the occurrence of a hot day, sud- 

 denly increase the number, often to 15 or 20 eggs a day, or upon 

 a chilly day the number deposited may drop as suddenly to one 



egg or none. 



DISPERSION. 



Wlien cotton and other annual plants die in the late fall the red 

 spiders are forced to seek green food. Many of them manage to 

 locate upon the several kinds of weeds (mentioned on page 11) which 

 remam green throughout the wmter. Smce these wild plants occur 

 abundantly in the borders of fields and on terraces and roadsides, 

 the pest frequently is found on cotton the following sprmg, in the 

 portions of fields where planters fail to clear these borders of weeds. 



The cultivated violet occurs frequently throughout the South, and 

 remains green through the winter. Infested violet beds have been 

 found from Virginia to Texas, and m many cases they are the sources 

 of infestation to near-by cotton fields. The mfestation to cotton may 

 arise directly from violets, if the beds are within a few hundred 

 feet of cotton (fig. 7), or from a series of migrations covermg con- 

 siderable distances. 



Fig. 6.— a severe example of red-spider work in a cotton field. Nearly all plants in the foreground are 

 in the condition shown in figure 5. The source in this case was certain pokeweed stalks growing in the 

 weed border seen in the upper right-hand corner of the figure. 



