Recently, Davis and Mavros (1956b) have been most successful 

 in rearing larvae on guinea pigs and nyii5)hs and adults on white 

 mice. Between feedings, ticks were held at 30°C. in a humidified 

 cabinet. The life cycle under these conditions required from 

 four to eight months. Larvae fed from six to fifteen days, most- 

 ly for eleven to thirteen days, and molted to nymphs ten to 

 twelve days later. This lot all reached the adiHt stage after 

 three nymphal molts, as follows: first to second instar, fourteen 

 to twenty days; second to third instar, seventeen to 32 days; 

 third instar to adults, 21 to 37 days. One third nymphal instar 

 specimen fed twice before molting to an adult male. This individ- 

 ual required lUO days postlarval feeding to reach adulthood while 

 the most rapid time for this interval, also for a male, was ninety 

 days. 



In an additional lot, six males and fourteen females required 

 three nymphal instars and two females \inderwent a fo\irth nymphal 

 molt. Three pairs fed twice in the last nymphal instar. The last 

 nymphal instar lasted from 26 to 65 days, but most required only 

 26 to 33 days. Females fed for eight to 21 minutes and mated for 

 ten to 27 minutes. Oviposition commenced eight to 58 days after 

 feeding and larvae hatched after eight to 2^ days. The namber of 

 eggs per batch ranged from 2J^. to 96, and while generally smaller 

 batches showed a higher rate of fertility than larger batches this 

 was by no means consistant. For instance, in one batch of 2^1. eggs 

 22 larvae hatched, one batch of 72 was entirely fertile, a batch 

 of 62 was about fifty percent fertile, and the batch of 96 eggs 

 hatched 81 larvae. The least fertile female oviposited a second 

 time without a second feeding or mating. The most fertile fe- 

 male fed a second time and then oviposited though without having 

 mated since the first feeding three months previously. 



Further observations showed that while larvae take a small 

 amount of blood within an hour of attaching to the host, the bulk 

 of the blood is ingested shortly before completing feeding. Molt- 

 ing ticks free themselves from the exuvia within a few minutes 

 after the skin splits. Mating and feeding takes place readily in 

 daylight. Feeding adults stand perpendicularly, bracing themselves 

 against the tube; when partially distended they fall over on their 

 dorsum to complete engorgement. 



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