days, mean five days; at 3CPC.) than do later instaxs that feed 

 on an average of two days (minimum one day, maximum five days ) 

 after molting (Jobling). Dr. G. E, Davis reports (conversation) 

 that nymphs kept at normal room temperature require eight days 

 before molting to the second nymphal instar and longer for suc^ 

 cessive instars, 



Jobling noted that first instar nymphs feed on an average of 

 25 minutes (minimum thirteen and maximum 87 minutes). Second and 

 third instars average about foiir minutes less (minimum eleven and 

 maximum 5^ minutes), while fourth instar feeding is the longest 

 (average 26, minimim 17, maximum 53 mnutes). Jobling believes 

 that the longer final nymphal feeding may possibly be necessary 

 due to the requirements for metamorphosis to the sexually mature 

 advilt stage, which demands more nourishment than simple nymphal 

 instar- to- instar development. These figures are in essential 

 agreement with those of other students of the life cycle, mentioned 

 in preceding paragraphs. 



Shortly before feeding is completed, a clear fluid begins to 

 emerge from the coxal organs of all nymphal stages (as it also 

 does from both adult sexes during feedings) and continues to issue 

 until after feeding is completed and the tick has left its host, 

 (See REMARKS below). 



Nymphs are more resistant to adverse temperature and humidity 

 factors than egg and leirval stages, during which there is a much 

 higher mortality than among nymphs. This is also agreed by all 

 workers . 



The ratio of males to females is practically equal (Jobling). 



Males emerge from the last nymphal molt with a strong sexual 

 urge and may fertilize several females before feeding. The aver- 

 age male feeding time is sixteen minutes (maximum /|.2, minimum nine). 

 After feeding they are less active and less eager for females and 

 bury themselves in soil. Three or four days later they again be- 

 come active and seek females, ^Jobling ~J 



Females can be fertilized immediately after molting and several 

 males may engage a single female before she seeks a blood meal. A 

 female feeds for an average of 35 minutes (minimum 21, maximum 92). 



_ 1Z^2 _ 



