92 LIFE HISTORY OF NORTH AMERICAN TICKS. 
number was 59, and the average number was 1,517. This maximum 
record was made by a fully-engorged female collected on a rabbit 
May 7, 1909. This was the largest engorged female seen by us, 
measuring 11.3 by 7.5 by 5.8mm. Deposition began on the seventh 
day after collection and continued for 20 days. The largest number 
of eggs deposited during one day was 303, which occurred on the first 
day of oviposition. 
The preoviposition period of the eight females ranged between 
4 and 9 days, with an average of 6.4 days. The period of oviposi- 
tion varied from 5 to 20 days. The female having the shortest 
oviposition period probably died prematurely. Death of the females 
usually took place on the day following the completion of egg laying. 
In one case it occurred on the fifth day after deposition ceased. 
Eges kept out of doors were, in one instance, found to hatch in 22 
days. The mean temperature during this period was 90° F. and the 
total effective temperature 1,034° F. In the laboratory the incu- 
bation period has been found to be as short as 23 days for eggs 
deposited in June. During this period the mean temperature was 
82° F., an effective temperature of about 902° F. being required for 
hatching. The longest incubation period observed in about 25 lots 
of eggs deposited during the spring and summer was 40 days. 
TaBLtE XXIV.—Incubation and longevity of larve of Hemaphysalis leporis-palustris. 
| Temperature easing incubation 
eriod. 
Mini- perio 
Hatch- | mum Larval 
Eggs deposited. ing incu- All larvee dead. lon- ee 
began. | bation gevity. Aanie | Mahi Total 
eriod. ox F | age | effec- 
Pp mum. | mum. | daily hive 
mean 
Days Days. oe, bad Oe tie its 
May 20-23, 1906_......] June 20 32) |) Mare 5 lO07 see eee st: lee Se cael (A PIES 3 alls 
May 24-29, 1906.__....| June 23 al |. .a-6 dossier Pee te eee | SBE aac ose (eect. - 
Sept. 2-5, 1906........ Sept. 26 25.) May: 11,1907 2. -- 5.5.) Wie il 22 sos wee | ee ee ee 
Sept. 4, 1907_........- Sept. 27 24 | Apr. 13, 1908 (sev- 199+] 102.0 50.0 | 78.72] 821.5 
eral alive). 
Sept. 7-9, 1907........| Sept. 30 24 Mar 17, 1908 (one 168+) 102.0 50.0 | 77.3 788.5 
alive). 
June: 2951908 . 2.22... July 21 23 | Sept. 21, 1908........ 62 94.0 70.5 82.25 | 902.75 
May: 6.1909. <...52250- June 8 34 | Jan. 22, 1910 (one 228+ 89.5 59.0 | 81.49 |1, 308.75 
alive). 
June 18, 19091_....... July 9 22 | Sept. 18-28, 1908__...| 71-80 102.0 81.0 | 90.0 |1,034.00 
‘Atprai4; 1910.52.00. May 23 40 | July 19 to Aug. 20, | 57-89 90.0 | 51.5] 70.91 {1,116.50 
1910. 
May: 7, 1910! 2.52 Tunens9 Cr al Eetane: dona eee -| 40-72 | 100.0 59.0 | 77.29 |1, 285.75 
June —, 1910......... RY. V4 | oe = 2 Web. 3; 1902-2 eee AVAS tise ous po taines SEP (cea: = 
1 This lot was kept out of doors. 
The larva (Tables XXIV, XXV).—The longevity of the larve has 
been found to be as great as 258 days under favorable conditions. 
The larvee which survived for this period hatched on June 20 and thus 
passed through the summer months, which are the most unfavorable 
to long survival. Many lots of larve which hatched early in the 
summer of 1909 died in about two months. The excessive heat dur- 
