99 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 5.3 mm. 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. 
Eggs 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. 
TaBLE XXIV.—Incubation and longevity of larve of Hxemaphysalis leporis-palustris. 
| 
| Temperature eee incubation 
eriod. 
Mini- - 
Hatch- | mum Larval 
Eggs deposited. ing incu- All larvee dead. lon- eae 
began. | bation gevity.| woaxi- | Mini = Total 
period. sp _ ge effec- 
mum. | mum. | daily tive 
mean . 
Days. Days. eae oe °F. | "Kh 
May 20-23, 1906_......} June 20 32) Maras. lOO aca tee 258)" | it ode. Alo. aca h Rage ee 
May 24-29, 1906_._....| June 23 Sie |e Ae Most we SE 255 coe Soe Sales ata eee | 
Sept. 2-5, 1906__...... Sept. 26 25) May 1, 190725 8 eis a] Meee alee ees |e ee 
Sept; 4, 1907253. =: Sept. 27 24 | Apr. 13, 1908 (sev- 199+} 102.0 50:10) |) 78. 7 821.5 
eral alive). 
Sept. 7-9, 1907._......| Sept. 30 24 | Mar. 17, 1908 (one 168+} 102.0 bOLO)| Wias 788. 5 
alive). 
June 29, 1908......... July 21 93.\| Sept oietsogh ete. Gs 94.0] 70.5 | 82.25} 902.75 
May;6,,190922. 2242-8 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-SO 102.0 81.0 | 90.0 {1,034.00 
Apr i4: ASLO sf asks | May 23 40 | July 19 to Aug. 20, | 57-89 90.0 51.5 | 70.91 {1,116.50 
1910. 
May 7, 1910__.........; June 9 34 |... -- GOs ar eS R072 | 100.0 59.0 77.29 |1, 285. 75 
June —, 1910......... Fialive 14 eee 2 Hebsis lols oe eee ee 204 i Sree ee nee asailecoc: =. - 
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 larve 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- 
