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The seasonal activity of the adults of 13 tick species was studied on cattle herds in the Central Province of Zambia from 1969 to 1972. The six main species, Boophilus decoloratus (Koch), Hyalomma marginatum rufipes Koch, H. truncatum Koch, Amblyomma variegatum (F.), Rhipicephalus appendiculatus Neum., and R. evertsi Neum. behaved as previously described for the Southern Province. R. compositus Neum. appeared from August, with peak numbers in September-October. R. simus Koch and R. tricuspis Don. appeared from October, for seven months and three months respectively. R. supertritus Neum. and Ixodes cavipalpus Nutt. & Warb. had a brief activity season from November to January, and R. pravus gp. and R. sanguineus gp. were active from December to July. The distribution of ticks over the body of cattle was determined by fractionised collections, which gave reliable quantitative information for nine of the species. A limited number of collections from sheep, goats and dogs are analysed in relation to season. Collections from 127 wild animals, mainly along the escarpment and riverine bush of the Zambesi, are recorded.

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External egg morphology of the camel tick Hyalomma dromedarii was studied. Injection of egg-laying females with 1% trypan blue resulted in incorporation of vital stain in the oviposited eggs. Daily measurements of fresh eggs revealed changes in egg length and width during embryonic development. Scanning electron microscopy showed the outermost layer of the egg to be spongy and porous containing clear pits of different sizes. An elevated longitudinal hatching ridge encircled the egg chorion. The development of cephalothorax, appendages, Malpighian tubules, and rectal sacs were monitered.