44 
NORTH AMKKM'AX FEVEB TICK A\l> OTHEB SPECIES. 
Table IX. Ovipo&ition of Argas miniatus at bulla*. Tex. Continued. 
When collected. 
■ -1 . 
'-"- Num- 
ment. i |,, 
Num- 
ber of 
Third 
engorge- 
Total 
num- 
ber of 
eggs. 
May L2 

"iso 
193 
" Oct. "22^23" 
3a 
113 
1).. 
Do 
Do 
Aug. 8- U Aug. 14 Aug. 24 11 
Aug. 9-10 Aug. IS A ... 7 
Aug. in ii Aug. 16 Aug. 25 10 
Aug. 15-16 Aug. 21 Sept. 4 15 
Aug.17-18 
Aug. 23-24* 
454 
I)<» 
1).. 
148 

Oct. 17-18 
50 
I)., 
Mar. 24 
Do 
Aug. 7- 8 Aug. 17 Aug. 24 
Aug. 1- pt. 2 10 
55 
154 Oct. 16-17 
185 
a Dead. 
engorgement. 
Adult ticks weighed before and after engorgement were found to 
increase in weight more than 300 percent. 
In order to determine the incubation period, 35 daily lots of eggs, 
deposited between May 16 and September 1, were recorded. Of 
these, four lots commenced hatching in 14 days, 26 in 15 day-, and 5 
in 16 days. In the incubator eggs deposited August 2] and subjected 
to a mean temperature of 99.8° hatched on August 29, the maximum 
temperature being 108°. From experiments carried out by placing 
eggs and seed ticks in an ice box and exposing them continuously , 
these were found to be exceedingly resistant to cold. Eggs deposited 
August 27 were exposed from September 8 to October 1 to a mean 
temperature of 48.9°, a maximum of 67° and a minimum of 37 . 
These commenced hatching October 6. Two lots of larvae, one of 13, 
that hatched September 2, and a second of 30, that hatched Septem- 
ber 8, were exposed in the ice box from September 8 to October 22 
to a mean temperature of 45.9°, the maximum being 67 c and the 
minimum 36°. These were all alive when removed and were as active 
as ever October 25. 
At Dallas larva? kept submerged in water to a depth of about an 
inch lived for 11 days. 
The length of life of this tick and its capacity to exist in the absence 
of a host are surprising. At Dallas larvae kept confined in summer 
'in pill boxes immediately after hatching lived about two month-. 
some surviving somewhat longer. Larvae of Margaropus annulatus 
kept under similar conditions live for but two or ihret days at the 
most. In Australia Robertson found the nymphs to live in pill boxes 
for about the same period as we have found the larvae to survive. 
The longevity of the adult, however, is most remarkable. Riley 
reports an adult specimen as remaining alive in a corked vial without 
food for five years. Robertson has found them to remain alive for 
two years and three month- and Dr. Cooper Curtice' informs US that 
he has kept them alive without food for more than two year-. In 
our experiments adults collected in March. 1906, and kept in corked 
oProc. Ent. Soc. Wash., [II, p. L21. 
