188 LIFE HISTORY OF NORTH AMERICAN TICKS. 
among those ticks which have once been attached to a host in the 
adult “stave. Hot weather also appears materially to shorten the 
longevity of both sexes. 
Taste LXXXVIII.—Longevity of adults of Dermacentor occidentalis. 
Number. 
Date molted or collected. All dead. aay 
Male. | Female. 
1910. Days. 
Molted only, 42sec. seen --sa5 2-6 beh 0 1 |, Oct. 18=Nov.i28, 1910 set sh ee asec 106-147 
Molted, Aug. 10.- 29 ZOOM PAUE. 4 SOll cc. cee aeeee see ee 359 
Molted, Aug. 15.... 1 Pee re May: 27, Olt Sice se oeeek eee cee 285 
Moltied. Avg. 15-2052 | fe. 2 ce ac = 2 2 May SsLOUe ts 2 foes a ee eee eee 266 
MOA ATE dpe ere one ees 0 1 Nov, 28-Dec::20, 1910... ..2 ncaa 103-125 
Molted, TORO). Jai. SO Sen 2 OU May 20; 1911. co.cc em aee eee oes 26! 
Collected, SAUDI peat ates aee nods en 0 1 Sly LO Aue 8 O10! ace eee ee 118-147 
DOtee eas cree. Saeko eee eee 1 MIT ¢ COLOR Se aac ns cc aetettaters i= 
Collected; Apryos. 2: sce. -4- = se ne 2 Si) Aug. 18-3), 191022. cotett cee cee 135-148 
Collected, AIS cee seco oss a osene 8 4| June 18-July 18; 1910 eee adacsat 71-101 
Collected, WA DTS ste cae = Bice cssme 0 5 | July 18-Aug. 18, 1910; inn oo 82-113 
Collected, May 28 saneacee. oe sere 0 2 5dO\2). . a vecpatnute eee ee as caeeee 51-82 
Collected, OY. a Dae ie ee eee ae 6 5 Apr. Si MOM. See GOES cee 166 
Collected, CO CERIGL Ue | eee cert: 0 1 | Mar. 20, TOU Soe bee ees ees 145 
Copulation of this species has not been observed before attaching 
to a host. 
any time between one and several days after attachment. 
Mating has been seen to take place upon bovine hosts 
In one 
case a female became fully one-half engorged before she was visited 
by a male. One female which was not observed to be fertilized 
became nearly engorged and dropped in about the normal engorge- 
ment period. However, no eggs were deposited by this individual. 
Tasnte LXXXIX.—Engorgement of adults of Dermacentor occidentalis on bovines. 
Females dropped engorged—days 
following attachment. 
Date females |Num-| State of en- State of en- 
applied. ber. | gorgement. Date attached. Total | gorgement. 
2] 4)]6)] 71 9 J10 |17 | number 
dropped. 
1910 1910 
IAIN s Ooccsscsscst- 5 | Slightly to} Apr.9 -......--- oT ees |beae 1| Fully. 
one-fifth. 
1.55 0) sy -) Seete e ae 2) Wnengorpeds| Apr. 22) <a oeriee|cm ema | ae see ete 1 1 | Two-thirds. 
Mayr 0 ssccess: 10 | Unengorged | May 9.....---- Cl TP) bee 5 | O n e-fourth 
to one- to two- 
eighth. thirds. 
Maw 20)... <= -58 1 | Unengorged.| May 20......-- 1 1 | One-half. 
Junei4.3 3534.54: 3 | Slightly... .-. Juner4..2.-25% oA) 2 35] US saese 1 | Two-thirds. 
RTH yt estes eee Sl ee Gi. as JUNC MSOs cohen eels es a ke 1 Do. 
Aug. 26-31 ....--- 8 EBEREOrEPY Aug. 31-Sept. 4.)...|.-.. ated aaah a 2) Fully. 
BeDisics ows sccns- A eters Oia statclae Septs 24. os. aloe |oce algal) 1 | One-eighth. 
Males have been observed to remain upon a host for 31 days. 
Females which had become one-fifth engorged upon one host were 
found to attach to another host when given an opportunity. In 
most cases ticks applied to a bovine attached within less than one. 
day thereafter, but in a few instances both males and females were 
