THE NORTH AMERICAN CATTLE TIOK. 115 
TaBLE XXXIX.—Preoviposition, incubation, and longevity of larve of Margaropus 
annulatus out of doors. 
All larvee dead. 
seo eys Preovi- A Minimum 
Date females | Oviposition syle Hatching P . . Larval 
position incubation Period . 
collected. began. period. began. period. ai eam longevity. 
dropping 
of female. 
Days. Days. Days Days 
Aug. 6,1906 | Aug. 19,1906 13 | Sept. 10,1906 23 | Apr. 9,1907 246 11 
Mar. 20,1907 | Mar. 24,1907 4| May 30,1907 68 | July 20,1907 122 51 
May 8,1907 | May 12,1907 4 | June 22,1907 42 | Aug. 27,1907 111 66 
July 3,1907 | July 6,1907 3 | July 27,1907 23 | Oct: 5, 1907 94 69 
July 31,1907 | Aug. 3,1907 3 | Aug. 26,1907 24 | Dec. 10,1907 132 106 
Aug. 21,1907 | Aug. 25,1907 4 | Sept. 21, 1907 28 | May 22,1908 275 244 
Sept. 25,1907 | Sept. 30,1907 5 | Mar. 27,1908 180 | June 30,1908 279 95 
Mar. 20,1908 | Mar. 29,1908 9 | May 22,1908 55 | Aug. 13,1908 146 83 
July 1,1908 | July 5,1908 4] July 28,1908 24 | Nov. 8,1908 130 103 
July 21,1908 | July 25,1908 4} Aug. 18,1908 25 | Mar. 31,1909 253 225 
Aug. 12,1908 |} Aug. 14,1908 2 | Sept. 9,1908 27 | May 13,1909 274 246 
Sept. 16,1908 | Sept. 23,1908 7 | Dec. 15,1908 84.| May 4,1909 230 140 
Oct. 5,1908 | Oct. 17,1908 12 | Mar. 23,1909 158 | July 5,1909 273 104 
May 24,1909 | May 29,1909 5 | June 28,1909 31 | Aug. 15,1909 83 48 
Aug. 2,1909] Aug. 5,1909 3 | Aug. 27,1909 23 | Sept. 25,1909 54 29 
Sept. 6,1909 | Sept. 10,1909 4| Oct. 14,1909 35 | May 7,1910 243 205 
Sept. 27,1909 | Oct. 4,1909 7| Mar. 4,1910 152 | June 12,1910 258 100 
Nov. 8,1909 | Nov. 20,1909 12 | May 24,1910 186 | July 21,1910 255 58 
The larva (Tables XXXIX, XL).—Iarve have been found to 
live as long as 246 days during cool weather and during midsummer 
from a few days to 100 days. The longevity of the larve given in 
Table XX XIX is based upon the entire number of eggs deposited 
by a female, the period being figured from the day the hatching of 
the lot began until all larve in the lot were dead. All were kept in 
large tubes with cloth tops and soil bottoms. These were set in the 
ground beneath a thin burlap shelter; otherwise the conditions were 
normal. 
Molting begins from the fifth to the twelfth day after application 
to a host and usually all larve molt to nymphs within 16 days after 
attachment. 
The nymph (Table XL).—After the larval skin splits the nymph 
crawls out and reattaches close to the old point of attachment. The 
larval skin sometimes remains attached to the host for several days. 
Nymphs have been found to become engorged and molt to adults 
as soon as 5 days after the larval molt. The period from attach- 
ment to the beginning of molting varies from 13 to 18 days. The 
length of the molting period of nymphs which become males is fre- 
quently from 1 to 3 days shorter than for those which become females. 
The adult (Table XL).—The number of males and females which 
transform from a given lot of nymphs is approximately the same. 
As has been stated, the males usualiy appear from 1 to 3 days 
before the females. Both sexes crawl from the nymphal skin after 
it has been ruptured and reattach in the immediate vicinity of the 
old skin, which frequently remains attached to the host for several 
days. Before starting in search of mates the males usually feed 
