A consideration of the tick-activity data for South Wales reveals that there are usually two peaks of female activity in this region, one occurring in spring, the other in autumn. On an experimental area, divided into eight plots, on the Margam Moors, Glamorgan, significantly varying population levels are present on the different plots, although the peak of activity on all of them is attained around the same period. The seasonal activity of the nymphal and larval forms in South Wales is essentially comparable to that recorded by Milne (1945a) in the north of England. There is reason to believe that in mid-Wales a single summer peak of tick activity exists.

The engorgement period of female ticks on cattle varies from 7 to 13 days. The tick shows a distinct preference for the hind region of cattle for feeding purposes. The differences in the mean populations of ticks on different breeds of cattle are not statistically significant, at least, on the six breeds tested in 1944 and 1945. In the case of cattle, tick density and fecundity of the female are not correlated with the physiological condition of the host.

In South Wales, the populations of ticks on sheep are significantly lower than those on cattle, even where both hosts are pastured on the same ground for similar periods. The seasonal activity of female ticks on horses follows the same general trend as that noted on cattle.