10 BULLETIN 416, U. S. DEPARTMENT OF AGRICULTURE. 
FIRST NYMPHAL STAGE (THE PROTONYMPH). 
As has been stated previously, it is only the female which passes 
through a second nymphal stage. 
Description.—The primary nymph (PI. Il, fig. 3) differs from the 
larva in having 4 pairs instead of 3 pairs of legs, in the somewhat 
increased size, and in the more oval outline of the body. Further- 
more, the bristles are slightly longer, and the segments of the legs 
become elongated in proportion to their width. The color,of the 
protonymph is usually darker than that of the preceding stage and 
the lateral pigment blotches become more evident in this stage. 
One of the most noticeable modifications in the primary nymph is 
the considerable elongation of the abdomen, the suture separating 
the latter from the cephalothorax lying in a position slightly more 
than one-third the body length from the anterior margin of the 
cephalothorax, whereas in the larva the suture nearly bisects the 
body. A series of measurements of the protonymph averaged, 
length, 0.213 mm.; width, 0.145 mm. 
The habits of the primary nymph are similar to those of the larva. 
It moves about more freely than the larva. Investigators of red 
spiders have claimed that the ab:lity to spin webbing appears for the 
first time in the protonymph, but no effort has been made to establish 
this point. ibe ; 
‘“Premolting”’ period.—Perkins (1897) makes no mention of a qui- 
escent period preceding the molting of the primary nymph. Ewing’s 
life-history table shows an average duration of 13 days for the resting 
period before the molting of this stage. At Batesburg the “‘pre- 
molting’’ period of the protonymph occupies a very few hours. Dur- 
ing these quiescent periods the body assumes a pearly or silvery 
appearance. Von Hanstein (1902) called this quiescent period of 
the primary nymph the “ Deutochrysallis.”’ 
Duration of the protonymphal period.—With the records of 6 indi- 
viduals upon which to base his conclusions, Ewing found that in 
Oregon the protonymphal stage required from 2 to 4 days, with an 
average of 3.16 days. At Batesburg 37 colonies completed the pri- 
mary nymphal stage. In March, in one case, this stage required 6 
days for completion, but in the summer the period is occasionally 
concluded in 1.5 days. The average duration of the female proto- 
nymphal stage for all records at Batesburg is 2.18 days. 
Molting process.—Of all the red-spider stages, those which are dis- 
tinguished with the greatest difficulty are the primary and secondary 
nymphs of the female. It is natural to presume, therefore, that no 
radical changes occur in connection with the molting process, and 
-this is borne out by observations. The time required was slightly 
over 3 minutes in the case of the one operation observed. (See 
fig. 3 for the cast skin of the protonymph. ) 
