THE RABBIT TICK. 93 
ing August of that year was at least partially responsible. Engorged 
larve have dropped from rabbits as soon as the fourth day following 
attachment, but on a bovine 6 days was the shortest period of engorge- 
ment. The greatest number drop from the fifth to the eighth day, 10 
days being the longest time required for engorgement. 
TaBLE XXV.—Engorgement of larve of Hemaphysalis leporis-palustris. 
| 
Larve dropped engorged—days following application. Total 
: 7 ota 
Date elgg ap Host. | - number 
| ana) mate Mae pe RP Deg Stel AP eighth) Rg) 2 ap. keRraweR 
| | | 
Bos oe Se hh une e Phe ees = ef | cers. 
Sept. 30, 1907.....| Rabbit...) 0 0 0 Ollie 251] 27 | 33 7 5 1 98 
OCT 0 rl 90 ieee arr Oca. | 0 0 0 5 77 71 29 5 1 a 192 
Nov. 15, 1907..... Bovine... .| 0 0 0 0 19 75 | 27 11 2 0 134 
Mar. 11, 1908..... 0 |v ae | 0 0 0 0 0 13 19 4 0 0 36 
Mar. 19, 1908. .... poss acne| 0 0 0 0 1G ST v5 24 | 0 0 281 
| 
The molting of engorged larvee was observed in 384 cases. Larve 
which dropped in March at a mean temperature of 68.7° F. molted 
in 18 days, an effective temperature of 463° IF’. having been required. 
The longest period passed before molting was for 2 larve which 
dropped November 22, 1907, and molted 134 days later. The mean 
temperature during this period was 61.98° F. Unfortunately our 
records do not include individuals which engorged during the summer 
months. 
The nymph (Tables XX VI, XXVITL).—The greatest nymphal lon- 
gevity observed was 342 days. This record was made on two nymphs 
which were collected on a rabbit on June 19, 1909, by Mr. W. V. King. 
One of a few nymphs which molted from larvee April 19, 1908, lived 
for 307 days. A number of other lots of ticks, which were observed 
from the time they molted to nymphs, lived from 78 to 246 days. 
The longevity of a number of lots of collected individuals, which had 
become from slightly to one-half engorged, was from 34 to 334 days. 
The minimum engorgement period of nymphs which we have ob- 
served was 4 days, the last ticks dropping on the eighth day after 
application. 
TaBLE XXVI.—Engorgement of nymphs of Hemaphysalis leporis-palustris. 
T 
Date oes aP-!| Host. aoe 
plied. 
eed | ae feel zl) Be) 8 10. }emneee 
Oct. 29, 1907._....| Rabbit__.. 0 0 0 0 0 2 1 0 0 0 3 
Feb. 25, 1908. .... Bovine.... 0 0 0 0 0 1 0 1 0 0 2 
Apr. 4, 1908...... SG (0) eee Ow 0 0 0 0 3 6 2 0 0 11 
June 2, 1908...... VrGoe Le 0 0 0 5 24 14 2 | 0 0 0 45 
May 22, 1909_.....| Rabbit... 0 0 0 1 0 0 0 0 0 0 1 
