The Distribution ofIxodes ricinus(L.) on the Body of Cattle and Sheep

Abstract

Female ticks are almost entirely confined to head, axillary and inguinal regions of cattle. Larval and nymphal stages attach on the head and below the hock joints on the fore- and hind-legs.The percentage of females on the forequarters of cattle increases during the course of the season, whether in spring or autumn; during the early stages of a season's activity the hindquarters carry a greater number than the forequarters. Later in the season the position is reversed. Suggestions are put forward to account for this phenomenon.The head, axillary and inguinal regions are the major attachment sites of the female tick on sheep. In ewes the head region carries the higher percentage, but on lambs the axillary region is the most heavily infested. This difference may be due, to some extent, to the fleece of the ewes forming a barrier to the movement of unfed ticks towards the axillary and inguinal regions.Lambs carry a heavier infestation between the 21st April and 6th June than ewes on the same grazing. This phenomenon has been discussed in the light of previous work in Northern England.There is no reliable method of estimating the total infestation on cattle. A good picture of the seasonal incidence of the female tick on the host can be obtained from the hindquarters count. The standard count (the forebody) on sheep may be used for estimating total infestations.