53-1 Genus HaeniaphiiHidU 



Weights and measurements. 



Ruhr gives a iiuiulx'i- of data which 1 have compressed in tabular 

 form as follows : 



The foregoing measurements are of the length x hreadth x thickness; in the case of the 

 gorged female onl.y the largest size and weight attained is given. 



A female which weighed 334"5 mgr. laid 1858 eggs, and, after ovi- 

 position had ceased, she weighed 78 mgr. Hooker, Bishopp and Wood 

 note that a female which laid 2240 eggs measured ll'S x 7"5 x 5'3 mm. 



Insect enemies. 

 Ixodipha(justexa)U(n L. O. H(jward (1907, p. 875) was first discovered 

 in engorged nymphs of H. lejjoris-palustris taken from wild rabbits in 

 March and May, 1907, in Jackson County, Texas, by J. D. Mitchell. 



Summary and Remarks. 



H. leporis-paluslris requires three hosts upon which to feed in the 

 larval, nymphal and adult stages respectively, as was first shown by 

 Hunter and Hooker (1907), who state that it attacks wild rabbits in 

 such numbers in Montana, U.S.A., that the animals may be weakened- 

 and thus rendered easy to capture. The larvae remain upon the host 

 for 4-11 days, the majority taking 7-8 days to gorge ; nymphs remain 

 attached for 4-11, the majority gorging in 0-8 days. The males persist 

 upon the host which the females have abandoned ; they may die whilst 

 attached to the skin. Rohr states that copulation must take place at 

 night upon the host as he has never succeeded in observing the process 

 by day. The female remains attached to the host 17-25 days. The 

 time required for metamorphosis is infiuenced by temperature: Larvae 

 emerge from the egg after 22-29 days at -SO" C, or after 47-61 days at 

 ca. 22" C. ; nymphs emerge after 7-9 days at 30° C, or after 134 days at 

 16'5 C. ; adults emerge aftej- 10-17 days at 27C or after 89 days at 



