162 LIFE HISTORY OF NORTH AMERICAN TICKS. 
the longest period of engorgement observed was 14 days. In this 
case the larve were scratched off when between one-fourth and five- 
sixths engorged. 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. 
TaBLE LXXII.—Engorgement of larve of Dermacentor parumapertus marginatus. 
Larve dropped ongorbed dave following appli- 
cation. Total 
Date larvee applied. Host. peeeacrl 
Bley] Bah  SalyG 2) 71 Soil 8 Shoal ia Eee 
PR Sif L908 Fw ooo Sis cetsyemte Ceo Bovinesen ee =e OUR Ore Oe) eal ers i mies ene |) 13 
ANI 626 5 1908S Ss Sc ae sec ee eee lowe « dose es aks ON eOn EOF ON aie 2a OF POR sO oO ian0) 9 
OCU Oe1909F a eee een ees Squirrel. ...... OF Oe On ona cone On anO mins a0 23 
INO V4 5 1G0O Soe eeee oe acee Guinea pig. - OO SON SON eZ eee ER Sa ie: Pee enOlieaG: 20 
Marth 1910 82 es ee eae eed dOzeen- 282 OF Os) JON) On On a One 2a Ont 2250) 6 
Dept..28, LOLOL SS susaatceeose|cecies doses ONT ONO O70) | On On One AOR tao riers 8 
At a mean temperature of 87° F. molting occurred on the eighth 
day, an effective temperature of 350° F. having accumulated. 
TaBLeE LX XIII.— Molting of engorged larve of Dermacentor parumapertus marginatus. 
Temperature 
from drop- 
Engorged larve molted—days following dropping. . | ping to date 
iS first tick 
Date =| molted. 
en- i 2 
orge 
lary ms Host 5 fe 
ro Pe) (eee is 
pe = 5 Eig | a4 
2 | 8 | 9 |10/11}12)13] 14] 15/16] 19 | 20) 21 | 23} 24} 26| 39) 47] g Ey 3 cae 
2 ae g a 
S| Ss 7 fe R q 
3 ol Sia ie 
A Hla le i[< 
1908. Seg as ace 
Aug. 12 | Bovine...... 1 O.- OF O| OO} TO} OF OF 0} OF CO}, 0} 0} 0} Oh. (0) Ol 96 7G S506 
AAG AS I eas Ol cae 2 17 1) ONO} 0}. 10}, 40), 70)~ OC) 250) SO}, 0) 0) OOO Ole 296 ni 77a Some 
Ae 4a) sere Gon sacte 5 0} Oo} 2 3] OF OF OF OF OF OF CF OF OF OF OF OF O| 5/96 {76.5)/85.3 
MATTE Sal) | eaeee dov= es 3 Oo; Oo}; 3} OF OF OF OF OF OF OF OF OF OF OF OF OF OF 3/96 {76 [84.8 
AMIS UG Ile Fase Co oars 1 0} OQ} 0} A} 0} 0} 0}. 0} 0)" 0! 70} Ol 0} OO) 0) OSG 7G Stee 
INTE WA ee @Osasete 2+) 0} 2 Others missing. 0} 2)97.5/75 _ 185.0 
1909. 
Oct. 13 | Squirrel. .... 12 0} 0} oO} OF OF OF OF 4) 8] OF OF OF OF OF OF OF OF 12/87 {51 167.83 
Octe 14ae eee. Oecenss 5) 0} 0} OF OF; OF 61) A 2) 62) 0) 0}. OF O} 60} Ol) OF OO} 58% abt eae 
Oct dant ee. does. 5 oO} Oo} OF OF 1) Of OF 2 1) O OF OF OF OF OF OF OF 4/87 [51 {70.92 
OctsiGiateas dowae ks 2 0} of O| OF OF OF OF OF} OF :CO| Ij OF OF OF OF O OF 1186 [51 170.93 
Nov 3 Guinea pig. .| 2 oO} OF OF OF OF OF A} OF OF} OF OF OF OF 1) OF OF OF 1179 |41 |64.95 
Nov.10 |..-... dos 2-252 2 0} oO} OF OF OF OF OF OF OF OF OF OF EOF 1) OF OF OF 1/79 |41 (64.75 
Nov. i ~waee @Osocces 5 0} 0} OF O| OF} OF OF OF OF OF OF OF OF J 3] OF OF 579 |34.5)63.55 
Novell2i|P ss do: 2-252 7 0} O} O| O} OF OF OF OF OF OF OF O| OF OF OF OF 2 279 |20 [54.45 
INOVelSa|senee doorcce: 2 0} Oo} OF O| OF OF OF OF OF : OF OF OF OF 1] OF LY OF 279 [82 [61.35 
1910. 
Marsiuialasees GOs Soee 2 joaqogaga og afo hy oO lO} OF OO OF OF 192 53 68. 54 
Mar: 19)| 2s dove: -% 2 o| of OF OF Of OF OF OF O| 1] OF OF 1) OF OF O} OF 2/92 [53 71.82 
Oct. 1212" GOes os 8 OF YO) 50) SO SOO Oyen 0 0 0} 6 0 0} O| 7/94 |43.5)/71. 58 
Rotals\68--|e2elessleeeleoel Pee leee Palomo Meare ce S\leaeal\se ae[eeees 
