THE OCCURRENCE OF IXODID TICKS ON WILD MINK MUSTELA-VISON IN ENGLAND AND WALES

Four species of ticks found to infest 1391 American mink (Mustela viso n) in Britain in five years were, in declining order of frequency, Ixo des hexagonus, Ixodes canisuga, Ixodes ricinus and Ixodes acuminatus. Ixodes hexagonus and I.canisuga occurred on 40% and 2.5% of mink respe ctively. Infestation rates (the proportion of infested mink) of adult females, nymphs and larvae were similar and tended to be lower in summ er. The distribution of infestation size (the number of ticks per host ) for adult females describes a negative binomial. The mean infestatio n size of nymphs varied with the sex of the host and was 5.2 for males and 4.2 for females. Mink are competent hosts for I.hexagonus.