DERMACENTOR VENUSTUS 503 



[This tick sometimes causes much annoyance to human beings. 

 It was once most troublesome at Revelstoke. Specimens have 

 recently been found on fowls, turkeys and pheasants in Kent. 



[Other synonyms are as follow : Cynorhcestes pictus, Hermann, 

 1804; Crotonus variegatus, Dumeril, 1829; /. plctns, Gervais, 1844; 

 Dennacentor albicollis, Koch, 1844 1847; D. pardalinus, Koch, 1844 

 1847; D- ferniginens, Koch, 1844 1847; Ixodes holsatus, Kolenati, 

 1857 ; Pscudixodes-holsatus, Haller, 1882 ; Hcemaphy salts marmorata, 

 Berlese, 1887. 



[The female when fasting is 3*86 mm. long by 2 mm. wide. 

 The body is depressed, larger behind and reddish-brown in colour. 

 The shield is very large and extends to the level of the third pair 

 of legs, with a few large and many small punctations, milky white, 

 variegated with reddish-brown. Sexual orifice opposite the coxae 

 of the second pair of legs. Coxae of the front legs are deeply 

 bifid, the others with a moderate spine. When gorged light 

 brown, and may reach 16 mm. When depositing eggs the female 

 is mottled with dark brown above and below. The male is like 

 the female. The shield is reddish-brown, variegated with a milky 

 white pattern. Coxae of the fourth pair of legs three times the 

 size of the third. There is a sharp backwardly pointing spine on 

 the second palpal segment, also seen (but smaller) in the female. 

 Length 4*20 mm. 



[According to Mr. Wheier this is a very variable species both 

 in size and colour. It occurs in England on sheep, but not com- 

 monly. It has probably been introduced into Britain. Besides 

 the animals mentioned above it is also found on deer. F. V. T.] 



Dermacentor venustus, Banks. 



[The Rocky Mountain tick fever tick. This species has been 

 wrongly called Dermatocentor reticulatiis var. occidentalism. The correct 

 name of the carrier of Rocky Mountain tick fever is Dermacentor 

 vennstus, Banks (Hooker, Bishopp and Wood, Bull. 106, U.S. Dept. 

 Agric., Div. Ent., p. 165). 



[The female is from 13*8 by 10 by 6*4 mm. to 16*5 by 11*4 by 

 6'9 mm. when gorged; the male from 2*1 by 1*5 mm. to 6 by 

 3*7 by i '4 mm. The male reddish-brown ; scutum with an exten- 

 sive pattern of white lines, usually but little white on the mid- 

 posterior region, legs slightly lighter than scutum, joints tipped with 

 white. Female with scutum mostly covered with white, abdomen 

 reddish-brown, legs as in male. The nymph when unengorged 

 reddish-brown, when gorged dark bluish-grey ; the larva is yellowish- 

 brown when unengorged, slate blue when engorged. The ova light 

 brown, shiny and smooth. 



