V'u 



250 Phylum Arthropoda 



centric. About 40 ticks are placed in the depression of the capsule and 

 the girdle applied to the animal so that the ticks may feed on a clipped 

 area of the animal's belly. Two strips of %" adhesive tape, encircling the 

 animal twice, reinforce the margins of the girdle. If two capsules are 

 to be used the capsules are spaced so that their rims are about %" apart 

 and their centers in line with the long dimension of B. A total of 80 



ticks, half males and half females, may then 



.-./" ""\ t be placed on the rabbit. A large number of 



,.:• '} females may cause the death of the host 



\, \ through exsanguination. Female engorgement 



is completed in 8 to 10 days. The rabbits are 

 then sacrificed, the girdles removed and the en- 

 gorged females collected. The males are 

 destroyed. From 15 to 20 engorged females 

 per animal are obtained from a single capsule 

 girdle and 30-35 from the double. 



Oviposition and Hatching. For oviposition 

 the engorged female ticks are placed individ- 

 ually in glass shell vials %" in diameter and 

 i%" in length, the open end being securely 

 but not tightly stoppered with a plug of 

 cotton (Fig. 51). The vials are then laid 

 horizontally in rows on a screen tray as 

 illustrated in Figure 52. The trays are placed 

 almost in contact with moist sand in thermal 

 cabinets operated at about 22 ° C. Under these conditions oviposition 

 begins in approximately 6 days and is completed about 21 days later. 

 The female dies on completion of egg laying. 



Hatching is completed and the larval ticks are ready to be fed in from 

 5 to 6 weeks after the engorged females were placed in the cabinets. 

 Readiness to feed is indicated by the presence of a considerable amount 

 of white excretory material deposited by the larvae on the walls of the 

 glass vials. 



Fig. 51. — Diagram of 

 cotton stoppered ovipo- 

 sition vial containing en- 

 gorged female tick. 



Fig. 52.— Diagram of tray for holding oviposition vials. 



