50 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



to cattle is that suggested by Professor Lounsbury, of attaching a bag 

 to the scrotum of a bovine. In this way the various stages of the ticks 

 can be applied, examinations made and the ticks removed as they drop. 

 All of the Ixodids thus applied by the writer have attached. Some 

 species, however, Dermacentor variahilis in particular, attach with con- 

 siderable reluctance. In this way by removing the bag and with it 

 the unattached ticks at the end of a given period and then making 

 examinations twice daily and removing the engorged ticks from the 

 bag (which has been re-attached), the exact periods of engorgement 

 can be determined. In order to prevent the removal of the bag from 

 the scrotum, a harness has been arranged and will be found necessary. 



In determining the life cycle of ticks that attach to small animals, 

 such as dogs, rabbits, squirrels, fowls and others, the only satisfactory 

 arrangement found has been a cage made of wire of about one fourth 

 inch mesh, permitting the ticks to drop through into a pan beneath. 

 This cage made of a wooden frame should have the joints set in white 

 lead or putty in order to eliminate all possible hiding places, into which 

 the ticks might crawl for protection. Nails inserted in the frame 

 serve as good posts, preventing the ticks from crawling again to the 

 cage. In the pan or tray under the cage may be placed strips of 

 paper beneath which the ticks will crawl. It has been the practice to 

 place a ring of white axle grease about the rim of the pan or tray to 

 prevent the escape of any of the ticks which have dropped. Another 

 way of preventing their escape is by setting this pan or tray in a 

 larger one filled with water. When the examinations are made the 

 tray can be removed, the ticks collected and the cage cleaned with lit- 

 tle difficulty. The plan of this tray was first suggested to the writer 

 by Professor Lounsbury and is similar to that which he has used. 



Many ticks will molt when but a small amount of moisture is sup- 

 plied, whereas others, as the species of the genus Ixodes, require much 

 more. As the engorged ticks are removed from the bag or tray, it has 

 been found that favorable conditions are furnished by placing them in 

 pill boxes upon moist sand. These pill boxes are prepared by punc- 

 turing the tops and bottoms, or better yet, furnished with gauze tops, 

 to permit of free circulation. Still more favorable conditions are fur- 

 nished by inserting in sand test tubes from which the bottoms have 

 been removed. As stoppers for the tubes, absorbent cotton will largely 

 prevent too humid an atmosphere, if protected from rains. A large 

 tray has been used filled with sand into which the tubes have been in- 

 serted and on which the pill boxes have been kept. By sub-irrigation 

 the amount of moisture furnished can be kept nearly constant with- 

 out interfering with the pill boxes. This sub-irrigation is best fur- 

 nished by use of a large cylinder tube extending to the bottom of the 



