Ixodidae 



251 



Engorging of Larvae. The host rabbit is placed in 68 count white 

 muslin bag 14" by 18" in size. The larvae from 4 oviposition vials are 

 quickly placed in the ears and about the head of each animal and the 

 bag securely tied. The bagged animals are then placed in cages sup- 

 ported on frames and racks as illustrated in Figure 53. The cage frames 



52 



Fig. 53. — Diagram of cage rack and cages used in rearing of large numbers of larvae 

 and nymphs. Capacity of rack is 12 cages. 



are made of %" wrought iron rods welded in place, painted with alu- 

 minum, and are 15" x 17" by 18" high. Twenty- four hours later the 

 animals are released and the bags and the unattached ticks clinging to 

 them burned. A 10 ounce canvas bottomed bag with an 80 count muslin 

 top is then placed over the supporting frame containing the cage and 

 tied. The canvas bottom has a few small perforations in it to permit 

 drainage into sawdust filled trays below. The frame within which the 

 cage is supported serves to keep the bag from actual contact with 

 the cage thus preventing holes from being gnawed in the cage bag by the 

 tick host. When the feeding is done at room temperature the major 

 portion of the larvae complete engorgement and drop in 5 days. Tem- 

 peratures above or below shorten or lengthen the feeding period. 



