THE RED SPIDER ON COTTON. 3 



day in summer weather. During tlie warmer months the eggs hatch 

 in about four days after being laid. 



The newly hatched red spider, called the larva, is almost round, 

 has six legs, and is nearly colorless. It begins feeding at once, and 

 (in summer time) after two days' activity it becomes quiet, darkens 

 in color, casts its skin for the first time, and emerges as the primary 

 nymph with an added pair of legs — making eight. 



The primary nymph becomes larger in size and darker in color, 

 but gives no indication of sex. Feeding continues actively and at the 

 termination of another two-day period (in summer months) a second 

 molting occurs which gives rise to the third stage — the secondary 

 nymph. 



With this last nympnal stage the first indication of sex appears. 

 As with the preceding stages, two days usually suffice in summer 

 for the completion of this period, at the end of which time the 

 skin in shed for the third time and at last the perfectly developed 

 adult mites appear. At the occurrence of each molt the skin splits in 

 two, crosswise, and the creature crawls out of the two halves. The 

 old cast skins are usually to be seen in abundance among the fibrils 

 of the web. 



THE ADULT MALES AND FEMALES COMPARED. 



Concerning the relative abundance of females and males it may be 

 said that there seems to be a predominance of females throughout 

 the summer, but toward the approach of cold weather the occurrence 

 of the sexes becomes more nearly equal. The period of life of the 

 adult female varies from 17 days in midsummer to several months 

 in winter. The male is shorter lived. As before stated, the female 

 is decidedly larger than the male, more rounded behind, and of a 

 much deeper color. She does not move about much, and when she 

 does her motion is rather slow. On the other hand, when not mating, 

 the male is frequently seen moving rapidly about. The body and 

 legs are well beset with bristles, which are somewhat more con- 

 spicuous in the males than in the females. The eyes, consisting each 

 of two orbs, one close behind the other, are situated near the front 

 edge of the body directly over the second pair of legs. 



MATING. 



Almost immediateh' upon becoming adult, the red spiders mate 

 and begin egg laying. The males seem to recognize unfertilized 

 females with ease. The first eggs are frequently deposited on the 

 same day upon which the transformation occurs from the last 

 nymphal to the adult stage. 



