30 
between the genital opening and the anus ; two on 
each side of the anus (perianal) ; and one triangular 
posterior shield, carrying the anal orifice at its anterior 
corner. Female has dorsally three longitudinal grooves 
on the abdomen, ventrally, two bell-shaped grooves, 
the first has its apex at the vulva, the second at the 
anus. 
(i) Evi ricinus (= reduvius). —The castor-bean 
tick. S . Sides of anal shield divergent {i.e., the anal 
shield is ‘ open ’). Scutum covered with very fine 
hairs (pubescence), covers the greater part of back, 
and is not fringed with hairs behind. Coxa I with a 
strong spine internallv only. Tarsi not knobbed. 
Ventrally, the rostrum has a little knob just behind the 
base of the palp. 
2 . Anal grooves prolonged behind the anus, 
divergent. First segment of palpi short, not forming 
a horn directed forwards. Scutum longer than broad, 
with rounded or angular sides (not concave), has 
cervical and lateral furrows. Coxa I unicuspid, tarsi 
not knobbed. This tick is common on sheep, goats, 
and cattle, Europe. 
Pathogenicity. —Transmits P. bigeminum. 
It is probable that Evi ricinus takes infection (P. 
bigeminum) in adult stage and gives in larval and 
nymphal stage. 
Bionomics :— 
i. 
2 . 
Egg laying - 
Larva 
100-1,000 eggs laid Time 1-2 weeks 
Incubation - - „ 6 ,, 
(a) On animals - ,, 
\b) On the earth. At 
the end of this period 
the first moult takes 
place and then results ,, 
4 
