14 BULLETIN 553, U. S. DEPARTMENT OF AGRICULTURE. 
with blood once and is ready to molt. One and one-half days is the 
length of time required by this stage. The second-stage nymph be- 
fore feeding is rather grayish and, like the preceding stage, is active. 
With one meal of blood and a molt the second-stage nymph becomes 
adult. The second-stage nymph, when fed, appears much like the 
adult (see fig. 2), but smaller. All stages after feeding are blood red. 
One and one-half days is required to bring the second-stage nymph 
to the adult. Unfed females are slightly larger than unfed males. 
Mites that do not get a chance to feed may live four or five months. 
