38 NORTH AMERICAN FEVER TICK AND OTHER SPECIES. 
cattle of ticks and the pasture-rotation system (to be used in con- 
junction with the former) for freeing the pastures. 
In the feed-lot or soiling system the basis is the time occupied for 
development on the host in connection with the time from the drop- 
ping of engorged females to the hatching of seed ticks from eggs 
deposited by them. In a tick-free inclosure, as a feed lot, cattle 
may be left to drop their ticks until it is time for the eggs from the 
first-dropped individuals to hatch. Information as to exactly when 
it will be necessary to move the cattle to avoid reinfestation is given 
in Tables I and II, which show the numbers of days at different seasons 
before ticks begin to oviposit after dropping and the time before the 
first eggs deposited will hatch. In July, 1906, for instance, this was 
from 25 to 27 days. The time required for all ticks to drop. from 
cattle, which indicates how long they must remain in one or more 
tick-free areas, is shown in Table VII. The period is from 31 to 59 
days. 
The data necessary for an intelligent plan of freeing pastures, by 
removing the cattle until the death of the ticks, are given in Tables 
V and VI, showing the period from dropping to the death of all the 
resulting seed ticks. The former table shows that if cattle were 
removed from a. pasture on June 20, 110 days later it would be per- 
fectly safe to consider it tick-free. 
The data referred to above, together with the results of other 
experiments, have been arranged to cover maximum preoviposition 
and maximum oviposition periods, for convenience, in Table VIII. 
Taste VIII.—Periods in the life history of the cattle tick wpon which means of control 
are based. 
| eee from POPP IRE Minimum | Maximum 
0 oviposition, aoe period from period from 
Minimum 4. : Adan ha alae p 
When ticks dropped. incubation dr GEping ot BR droppers 
Minimum. Maximum. period. hatching death of 
of eggs. seed ticks. 
1905. Days. Days. ‘Days. Days. Days. 
[STE OU Sn ce eet feline eet 2 3 5 - 43 46 | June 22 293 
1D) OL aE a Ss. Boats a obese 3 5 56 59 | May 31 271 
WECH2B» Roe Pores fee naan 21 41 54 75 | Aug. 28 248 
Meck 24d. ois f so keeles 21 41 47 68 | Aug. 15 234 
WECH25 Aa oe Oo ee ae 21 41 47 68 | Aug. 22 240 
1906. 
MEDD celta ate eee ola tain een 9 10 39 | 48 | Aug. 28 161 
YNioy oy Cae oe Ge Mae oe ohne 1 Bee 5 6 33 38 | Sept. 20 154 
ATOR ollie an ee Seeds 5 Aas 5 6 29 34 | Oct. 5 167 
Maye dir cate Pace Se Bee he e 2k 6 | 10) 27 | 33 |...-do 157 
IM Siva thre ove rete ak eee oe 6 10 | 28 34 | Aug. 9 97 
Miivel O)5e = 952. SOAs wee 22 nee 4 6 | 27 31 | Sept. 26 130 
I iii Oleg Se eee Be aN Pe 4 | 6 | 27 31 | Sept. 22 124 
LITO YS eee oe ae oe eed Se 3 | Sy 28 31 | Aug. 15 73 
MUNG 3 oc E KEE econ e aetees 3 | 5 | 23 26 | Aug. 26 a 83 
A AIMGY Ge eat Se Sear nee Ace see 3 Sa 23 | 26 | Aug. 6 a 61 
DO eee ae eee 3 | 5 | 23 26 | Oct. 6 122 
Af ubach Pere, ae eas See eam dl 3 4 | 21 24 | Sept. 26 106 
JUNC AS aaa Wrewace ease ezee at 3 4 | 22 25) |Eae doe 105 
RUT yaa) rhe A eR a eae 3 a 22 25 | Oct. 20 ail 
ULL ail eee eee oe oes Oe soe 3 4) 23 26 | Feb. 18 a 220 
DO} ees a Se Be Re Woe eS ee eee 3 4 24 27 | Jan. 23 194 
a These ticks were kept in open-bottom test tubes exposed to sun at all times. 
