Biology of H. leporis-2)cdustris 531 



Hadwen placed larvae on a tame rabbit (in Canada 12. iv. 1912) 



with the following results: 



6tli day 10 larvae dropped off gorged 

 7 44 



9-10 „ J6 „ 

 Total 107 



Nymphs: drop ofif gorged on the 6th day (from .rabbit?) according 

 to Hooker. Rohr states that they remain 6-11 days on rabbits and he 

 records an experiment as follows: 



6th day 3 nymphs dropped off gorged 



Hooker, Bishopp and Wood state that the nymphs remain 4-8 days 

 on the host, mostly 5-6 days; they carried out 4 experiments. Hadwen 

 placed 32 nymphs on a tame rabbit and 4 dropped off gorged after 6-7 

 days. 



Adults: according to Rohr, the $ remains 19-25 days on the 

 rabbit before it drops off gorged, whereas the </ remains on the host 

 long after the $ has left. Dead (/"s are commonly found attached to 

 the host's skin. Hooker, Bishopp and Wood had difficulties in 

 studying the adults; they only record the behaviour of 2 $ which 

 (h'opped off gorged on the 19th and 21st day respectively. 



Time required for metamorphosis. 



Egg to Larva: reckoned from the time the eggs are laid, according 

 to Rohr, the larvae emerge after 



47-61 days at ca. 21-22''C. (15 observations) 

 22-29 „ „ 30" C. (3 „ ) 



none hatched out at 35^ C. 



Hooker, Bishopp and Wood record that larvae emerge after 



22 days at ca. 32° C. (out of doors in vr.-vii. 1909) 



23 ,, ,, 28° C. (in laboratory in vi.-vii.) 

 34 ,, „ 28° C. ( „ „ v.-vi.) 



24 „ „ 25° C. ( „ „ IX. 1907) 

 24 „ „ 25° C. ( „ „ IX. 1907) 

 34 „ „ 25° C. ( „ „ V.-VI. 1910) 



