THE FOWL TICK. 538 
The period required for the incubation of eggs in August was 
found to be as short as 10 days, at least 437° F. of effective tempera- 
ture being required for incubation. Eggs kept in an incubator at 
a& mean temperature of 89.8° F. hatched on the ninth day, an effec- 
tive temperature of 421° F. accumulating. Rohr states that eggs 
kept at 35° C. (95° F.) hatch in from 8 to 11 days. 
Taste V.—Incubation period of Argas miniatus. 
Temperature during incubation. 
2 ! Minimum 
Eggs deposited. Hatching. perc oer i # Average ees 
" aximum.|Minimum.|} daily oe 
amiean: effective. 
Days. td rah ue ae SEG 
gume 29/9908)... 22 Tuliyali 9082 eee cee 13 93.5 70.5 81. 44 499.75 
falyle 1908s. 3-22. --2 |) July 14, LOS: 2852. 14 93.5 70. 5 81.98 545.75 
MUL yO 1OU8 erases oe a aliLy es LOOR! te 13 94.0 74.0 83.79 530. 25 
July si, 1908-022... 222 Aug. 12, 1908....:... 13 99. 0 73.0 86.15 561. 00 
ANIE:/D) 1908 .<.ce 2555 Augslos 1908.22). 11 99.0 73.0 86.59 479. 50 
PATICS (73 1908.52 S20 sees ATIC G WOO8s occ =e 10 99.0 73. 0 86.75 437.50 
Ao TOS 1908 = 2)-/=1- <-.-2.3 Aue 19 1908 soso oo. 10 96. 5 75.0 87.15 441.50 
Mies 18. 19082. 6... INTE SIE Te eee 13 93.0 75.5 83. 48 526. 25 
Aug. 24, 1908.........- Reptyn 1908 eres: 13 94.5 75.0 83. 40 525.25 
Ae RST 19082... Sept 1008s ke 12 97.5 74.5 84. 41 496. 95 
Sept. 3, 1908... .. Sel Be Sept. 15, 1908........ 13 97.5 74.5 83. 49 526. 45 
Hepts 30) 1908... 2: ==. Ock.'28; 1908-2... = 29 87.0 48.0 69. 00 755. 00 
OCT NEO BE eee Nov. 15, 1908........ 40 87.0 34.0 65.20 887. 00 
OGt.8; A908: 52.55 =. - Nov. 7, 1908....-...- 31 87.0 45.0 67. 00 743.00 
INOW 4; M9082. 2-52 2: Jani 22, 1909-25 222-5. 77 82.0 17.0 59.50 | 1,141.00+ 
Now: 95,1908... -2k).-=-= Beb.23;1909;, 2.5. 107 85.0 17.0 59. 50 1,582. 00+ 
INowe2e;, 1908532582 72 Ee 0L0) joel 3 Sewers aaa 93 85.0 17.0 58. 50 1,339. 00+ 
Marys O00: eo c/s aan May 20, 1909......... 20 95. 0 51.0 76. 50 671. 00 
Sept. 20; 1909: ..- 2.2. - OG 5 1 09S ee ears : 26 95.0 52.0 74. 50 860. 00 
(OY SESE Co eee ee Oct es 1909 2 ee - 23 94.0 52.0 73.10 693. 00 
Ocixoy1o09e Fe. 32 522. INov.'3; 1909: ..2-2:.. 29 92.0 51.0 71.60 831.00 
The larva (Tables VI, VII, VIII).—Seed ticks kept in pill boxes 
in the laboratory at an average daily mean temperature of 61.9° F. 
have been found to live as long as 164 days. During midsummer 
the longevity is about two months. 
TasBLE VI.—Larval longevity of Argas miniatus. 
Days Days 
Date hatching Date all larvee from Date hatching Date all larvee from 
began. dead. hatching began. dead. hatching 
to death. | to death. 
Are 9; A908 e5.- 2 Oct. '20, 1908... .-.- G2} |) Nove 2 plO08= se aaa 22 Mar. 22,1909. ..... 140 
Sept. 8, 1908....... Dech25, 1908-2... TOSS MINOW 9) NOUS Seca Mar. 27, 1909...... 137 
Sept. 25, 1908.....- Jan. 24, 1909....... 1210) Dees] S190Re Sees oe: Mar. 17, 1909...... 105 
Oct. 15, 1908......- Feb. 24, 1909.....- 132 | May 18, 1909.........- July 15,1909... ..- 77 
Oct 7, 190Gs.24-. . Mar. 30, 1909.....- 164 | May 24, 1909..........| July 27, 1909......- 64 
Oct. 21, 1908....... Mar. 27, 1909.....- 147 
At a temperature varying from 18° C. (64.4° F.) to 27° C. (80.6° F.) 
Rohr has found individual larve to live as long as 65 days. 
Ordinarily larvee do not commence to drop from the host until the 
fourth day following attachment, although one may occasionally leave 
the host a day sooner. All the larve which we observed engorged 
