44 NORTH AMERICAN FEVER TICK AND OTHER SPECIES. 
TaBLE LX.—Oviposition af Argas miniatus at Dallas, Tex.—Continued. 
| Second ov. iposition. 
Second _ = — Num- Third | | Total 
When collected. engorge- | | Num-| ber of SUEOTES: \ Reroit 
ment. | From—j| To— _ | ber of| €88s. ment eggs 
days , 
BF oS ara Toe eS Se ete ciate eae leva | bistanla tals otay| le atte eae i US Been Benen ne cern 113 
EaeAuiese8= || | Aug. 1 ‘| Aug. 24 11 180 | Oct. 22-23 454 
.-| Aug. 9-10 | Aug. 15 | Aug. 21 | 7} 199 | Sept. 3a 357 
‘| Aug. 10-11 | Aug. 16 | Aug. 25| 10 | pilOSa |e Soe ee 362 
Aug. 15-16 | Aug. 21| Sept. 4| 15] 148] Oct. 17-18 342 
| Aug. 17-18 0 Leet | Oil rephO! eeeprne ase eee / 50 
| Aug. 3204p aes DR SR | ees: ore eeeereeee 32 
| Aug. 7- 8 | Aug. 17 | Aug. 24 8 55 | Sept. 28-29 185 
ID Yo vie AS Tae Ss (pa aR er ee SYNE oo | Aug 18-19 | Aug. 24 | Sept. 2 10:|. 154) Oct. 16-17 237 
a Dead. b Last engorgement. 
Adult ticks weighed before and after engorgement were found to 
increase in weight more than 300 per cent. 
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 days, and 5 
in 16 days. In the incubator eggs deposited August 21 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, 
vhs 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 larve, 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° and the 
minimum 36°. These were all alive when removed and were as active 
as ever October 25. 
At Dallas larve kept submerged in meter 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 larve kept confined in summet 
in pill boxes immediately after hatching lived about two months, 
some surviving somewhat longer. Larvee of Margaropus annulatus 
kept under similar conditions live for but two or three 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 larve to survive. 
The longevity of the adult, however, is most remarkable. Riley 
reports an adult specimen as remaining alive i in a corked vial without 
food for five years.¢ Robertson has found them to remain alive for 
two years and three months and Dr. Cooper Curtice informs us that 
he has kept them alive without food for more than two years. In 
our experiments adults collected in March, 1906, and kept in corked 
a@Proc. Ent. Soc. Wash., III, p. 121. 
