162 LIFE HISTORY OF NORTH AMERICAN TICKS. 
the longest period of engorgement observed was 14 days. In this 
case the larvee were scratched off when between one-fourth and five- 
sixthsengorged. Six of the 8 were engorged sufficiently to molt. The 
first lot recorded in the table did not attach readily and for this 
reason those ticks which did not take hold at first were allowed to 
remain in the bag. Thus the larve which dropped on the ninth 
day probably did not attach until the third day after application. 
In the third lot recorded in the table the squirrel escaped from the 
cage on the afternoon of the fifth day after the ticks were applied 
and was not put back until the next morning. There is little doubt 
that some larve dropped in the meantime. 
TasLeE LXXII.—Engorgement of larve of Dermacentor parumapertus marginatus. 
Larve dropped engorged—days following appli- 
cation. Total 
Date larvee applied. Host. Caner 
V2) (OB 4 | BOT) 7) |e he a ean ease 
ATI seb as cine acinace net cies Bovine....... On VO SOU Oi LO Bath ot, AL One 0 13 
NER DOTA GORE Se secs cise cle ce tele cl ates. GOstaeenes OFA ON ON MON ea Orit Ol "O51 Or =O 9 
Ochs iNOS 5 a ee eet oe Squirrel....... Oo Os On 2 oa alae O On On ae 23 
INOVst4E IO00 oS Stet seen cee. Guinea pig= 2.) ONO OU On rare Seal aE On 10 20 
Wears Wl SOLO opie te Soe clesoes| eases Gossee sce! | ol OO Olea Ol Sl OW Bye 6 
(SL SF OG 24 Hel eee Sae Rniaceoecy lacerc Gowaceriee OF VOR PRON ONS Os On etn Ona 1 kO slates 8 
At a mean temperature of 87° F. molting occurred on the eighth 
day, an effective temperature of 350° F. having accumulated. 
TasieE LXXIII.— Molting of engorged larve of Dermacentor parumapertus marginatus. 
Temperature 
; from drop- 
Engorged larvee molted—days following dropping. 3 ping to date 
rst tick 
Date 2 molted. 
en- is g 
gorge 
Deve Host. . 3 b 
dro Ate lox 
ped. eS g/eldic F 
2 8 | 9 |10]11]12} 13) 14} 15] 16] 19} 20] 21 | 23} 24] 26) 39} 47) = E 3 
| a : 4/84 
=} ols | > 
A HiAala-i<a 
1908. ORs Fe Nels 
Aug. 12 | Bovine...... 1 0} Oo; OF} OF 1] OF OF OF OF OF OF OF CFF OF OF OF OF 1/96 {76 185.6 
Aug. 13) |: ..< dOwoect-u 2 1} 1} O| OF OF OF OF OF OF CF OF OF OF OF OF OF OF 296 {77 |86.8 
SAT LA WS she BD avcisctes 5 0} Oo} 2} 3] OF OF OF OF OF OF OF OF OF} OF OF OF OF 5/96 [76.5)85.3 
Aug. 15 |... GG- sacks 3 Oo] O} 3] OF OF OF OF OF OF OF OF OF OF O OF OF OF 3/96 {76 [84.8 
Ap. 16 |<< Gee ae 1 Oo} O} OF 1] O} Of Of OF OF OF OF O| OF OF OF OF OF 1/96 |76 [84.5 
Ue SL | as oe GGzcae 2+) O| 2 Others missing. 0} = 2/97.5|75 185.0 
1909. 
Oct. 13 | Squirrel..... /12 0} O| OF O} O} OF OF 4) 8 OF OF OF OF OF OF OF OF 12/87 {51 {67.83 
Octel4 |. 5 aa EGssactkz i) oO} of} OF OF OF 1) J 2} 1) OF OF OF} OF OF OF OF O| 587 [51 171.37 
OGtnL5 08 oe GO. cee | 5 oO} Oo} OF OF 1] OF OF 2 1 OF OF OF O OF OF OF OF 4/87 j51 |70.92 
OcteI6..)-' 2 AG. cecke 2 0] Of OF O| O} OF OF OF OF OF 1) OF OF OF OF OD OF 1186 [51 170.93 
Nov 9] Guinea pig..| 2 0} O| OF OF O} OF OF OF OF OF OF OF OF 1) OF OF OF 1/79 [41 [64.95 
Nov.10 |..... co (ore ae 0} oO} OF OF OF OF} OF OF OF OF OF OF OF 1) OF OF OF 1)79 |41 [64.75 
Nov: [22-25 (3 ko a es 5 Oo; oO} OF OF OF OF OF OF] OF OF OF OF OF J 3) OF OF 5/79 [34.5/63.55 
Woy? fs a dd sce ue 7 0} O| O| OF OF O} OF OF OF OF OF OF OF OF OF OF 2 279 [20 [54.45 
Nov.J3 jit... Gs cies 2 0} Oo} OF OF O} OF OF OF OF CF CFF CF O 1) OF YJ OF 279 (32 (61.35 
2 0} Oo} OF OF OF O} OF O} OF 1) OF OF OF OF OF OF OF 1/92 [53 (68.54 
z62 Oo} Oo} OF oO} OF OF O| OF OF 1] OF OF LY} OF O 0} 2/92 (53 |71.82 
|8 Oo} Oo} OF OF OF OT O 0 0 0} 0} O} O} O} 7/94 /43. 5/71. 58 
otal: 684(.. 3]. lossl eee eel eles eh PR I Ps 2s Pee ry ee ee 
| 
