F. C. Bishopp and H. P. Wood 
181 
Seasonal History. 
Like its nearest relative, Dermacentor albipictus, this species usually 
feeds only during the autumn, winter and spring. The collection of the 
Bureau of Animal Industry contains two lots of this tick taken from 
hosts in January 1906. Mr Nathan Banks’ collection contains speci¬ 
mens collected in June. This is the latest seasonal record of its 
occurrence on a host. During these investigations we have obtained 
nymphs on March 24, 1906, males and females on December 17, 1907, 
a female (W engorged) on February 4, 1910, males and females 
(slightly to | engorged) on November 25, 1910, males, females (un¬ 
engorged to fully engorged) on November 14-16, 1911, and all stages 
on December 5-6, 1911. 
Life History and Habits. 
Dermacentor nigrolineatus passes through both moults on the host. . 
Oviposition: The preoviposition period as observed by us ranges 
from 122 to 161 days (see Table VIII). These records are based on 
ticks kept in the laboratory on moist sand at temperatures slightly 
above those out of doors. The rate of oviposition closely follows the 
mean daily temperature. The greatest number of eggs deposited 
during a 24-hour period was 223, and the greatest total number 
deposited by a single female was 2848. The eggs of three ticks were 
counted daily. The first of these ticks measured 10 - 9 mm. in length 
(including capitulum), by 8'0mm. in width, by 5'2 mm. in thickness. 
This female was removed from a host on November 14, 1911, and began 
depositing on April 1, 1912, or 139 days after collection. On the first 
and subsequent days the following numbers of eggs were deposited : 
20, 3, 26, 50, 89, 145, 71 (2 days), 60, 82, 129, 179, 170, 132, 146, 137, 
49, 103 (2 days), 101, 161, 51, 79, 69, 123,100, 95, 68, 40, 0, 81, 58, 20, 
30, 19, 19, a total of 2705 eggs being deposited during a period of 36 
days. Another female which was removed from a host on November 14, 
1911, began ovipositing on April 11, 1912, or 149 days after collection. 
This tick measured 10'3 x 7'9 x 5 0 mm. The following numbers of 
eggs were deposited on the first and subsequent days: 46, 77, 171, 
162, 223, 137, 84, 219 (2 days), 219, 216, 132, 99, 147, 204, 153, 156, 
80, 45, 56, 50, 49, 26, 30, 21, 13, 17, 3, 11, 2, a total of 2848 eggs 
being deposited during this period of 30 days. A third tick which 
measured 8 - 6 x 7 - 5 x 42 mm. when it dropped off the host on December 
