8 LIFE HISTORY OF NORTH AMERICAN TICKS. 
Development of the Ixodidee—Continued. 
Genus Dermacentor—Continued. Page. 
The Rocky Mountain spotted-fever tick, Dermacentor venustus Banks. 165 
Descriptive... 2.22. eppirnae wear ee Sue Os: “oh wR. Et 165 
Host-relationship: «42.4.3 decss eas Sage ea 4 ee 166 
Geographical distrib wtion. : 2.522 soy elapse) 0 ea ee 2) SS 
Tate Distory-scsocs oc ree ee ee et ee 168 
Lifecycle. ss cnce ie deens Siew Sane Bee ee eee 179 
Heononne importance : 0 os. 69o525 52 a eee ee eee eee 180 
Natural (comitol a. 2% 2.5. eee eee eee a 180 
Artiieral control. o.2 se ee ke eo ee 180 
The Pacific Coast tick, Dermacentor occidentalis Neumann..........-- 181 
DESETIPUVEL 3. ees. 6 aos eos Le eee 8 oe eee ere ae 181 
Flost relationship. .....).222.222 25) 226 eee ee Se ae eee 181 
Geographical distributions: 22.22 Soc 6k oc ee ae ee 182 
eale dnastary:: ose Hes Sista. cic 2 a te ee a De 2 ste 2 ee 
Inne eyele 4: s ogceelue Saue faa. teks a ia eeey Sr te ee ee ee 189 
Heonomic importance |... 52s eee eee eee eee 189 
Natural control .2¢ a2 \cecmges eRe See Ws cee ene aici tee eee 190 
Artificial control; . 26.0... 40lne- ce kee s Abe eee ee ae 190 
The American dog tick, Dermacentor variabilis (Say). ..-...---------- 190 
Deseripiive 203 22 oi ee ee Ee eee ee he a 
Host relationship . . 02-2258 biee cece eee eee eee ee 191 
Geographical disivibution. 92.6252 5.054 eek oe ee 191 
Late history; 23. teens 5 Sis Bh ele: piss snes ai te ies ee 191 
date eyele. 2 3s uc5 02 eRe Bee Se eee eee 196 
Hconomic im portamces: 1-25 a es ee ee ee 197 
Natural comirol nfs 40 eee Bee eso Foe ee a ae 197 
Artificial comtrol:..5 2252 22s 22s hse ssoesseceet See eee eee ee cee 197 
The tropical horse tick, Dermacentor nitens Neumann........-...---- 197 
Deseriptive’s ...... 325 .c2ee sce 5) See a ae eae gs tet te eee ee 197 
Host celationships 2). 208. a4 oe Siete Galo ee eae nae Megs ae a Ora 198 
Geooraphical disteibutions S220. toc 23 eee oe eee 198 
Title HIStory... 2c obs bn 92 Ge re a ee 199 
ite Cyl. aod oe ao eee Sipe Scene ee ee 203 
Reoqnomicimporiance. «3... 22552. octseeee eae eee .. 203 
Natural comtrelt. tej cc6 eb) en ee 204 
Artificial comtrol: «2... 5. 02.02 aee nee ec eaere ae cee eee See 204 
Bibliosraphical references. 2/205 saws A) < Be Se et a ph ay 205 
ROR oo a eps Cee eee oS Patt See I aes Sse a aoe dole 215 
