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iJUREAU OF ANIMAL INDUSTRY. 



about one-half inch in length by about one-third as wide. The male is brownish 

 yellow, with dark markings; is only about an eighth of an inch in length, and, in 

 common with the early stages of both sexes, escapes general notice. It is generally 

 to be found beneath the distended female. 



The Blue Tick is nearly related to the common cattle ticks found in Australia, 

 North and South America, and in other parts of the world. Prof, G. Neumann, an 

 eminent authority on ticks, considers that it should be connected with the Amer- 

 ican cattle tick {Rldpicephalus annulatus Say; Boophilus bovis Riley) as a variety, 

 and he will probably classify it as such in a new work which he has in preparation. 



Notes on the life cycle of the species were given in the Agricultural Journal for 

 November 24, 1898, by Veterinary Surgeons Dixon and Spreull. I have reared 

 several different lots on cattle and goats, but have not yet traced all the habits. The 

 eggs to the number of several thousands are laid on or near the surface in grass stub- 

 ble or similar shelter and the larv?e on hatching ascend the grass or bush, as in the 

 other species studied. Two thousand two hundred and fifty larvte have been counted 

 at the top of a single blade of grass. By day and by night, through wind, rain, 

 and light frost, they remain at their posts. Grass found infested and protected 

 by a barrier of cut thorns was found to be still infested three months later, which 

 shows that the young ticks may live at least this length of time on the veld. 

 The female, after dropping from the host, starts laying in from five days to two 

 weeks in summer, while in winter at Cape Town, at a temperature of 65° to 70°, she 

 delays until the third or fourth week has passed. Similarly, the incubation period 

 of the egg varies from three weeks to three months. At a temperature of 85° to 

 90° in the incubator hatched eggs have been obtained in four weeks from the drop- 

 ping of the mother tick, which shows how heat hastens the development. Some 

 moisture appears necessary during the incubation period, as several batches of eggs 

 kept in dry boxes have shriveled and failed to hatch. 



The Blue Tick molts twice, but remains on its host through both changes, thus 

 differing materially in habit frojn the Bont, Bont Leg, Red, and other South African 

 species; it, however, becomes motionless, and appears as if devoid of life before both 

 molts. The larva begins to distend by the end of the second day of its attachment, 

 and seems to cease enlarging in from three to three and one-half days. Two days 

 later, under a magnifying glass, the body contents may be seen to have shrunk away 

 from the skin back to the mouth organs. Finally this larval skin ruptures across the 

 top in front, and the tick, now in the second, or nymph, stage, crawls out. This 

 change has been observed to take place as early as six days from the attachment of 

 the larva, and as late as the tenth. The nymph settles down near by and after a few 

 days distends, just as did the larva. In appearance, it resembles the adult female, 

 but its sides, in place of being parallel, converge slightly towards the rear. After the 

 fifth day from the molt, no further enlargement is perceptible, and doubtless feeding 

 has ceased. In another day or two the outlines of the adult are dimly distinguish- 

 able through the translucent skin, particularly across the front, and shortly thereafter 

 there is a rupture as before, and the tick makes its appearance as the adult. The 

 nymphic stage has about the same duration as the larval; in instances observed it 

 has varied from seven to ten days. The two stages together in numerous cases occu- 

 pied from fifteen to twenty days. The' male is very similar to the female in size, 

 color, and general appearance just after the molt, and, being small, one might be 

 easily mistaken for the other when viewed by the unaided eye. The female settles 

 down almost at once, and so, apparently, does the male; but the latter wanders much 

 farther and is therefore not easily traced. After a day or two males are seen crawling 

 about in the hair, evidently searching for mates. I am not certain how soon mating 

 takes place after moulting, but my observations lead me to conjecture that both sexes 

 feed for a short time, and that the male then lets go his hold and looks for a compan- 

 ion. However that may be, the females nearly all have mates by the fourth day. 



