476 QUEENSLAND AGRICULTURAL JOURNAL. [1 Dec., 1897. 
“The fluctuations in the number of ticks during a primary and subsequent 
invasions are entirely dependent upon one or several of the following conditions :— 
A. | B. 
I. | Cattle restricted to small areas. I. | Cattle running on open country. 
II. | Overstocking. | Il. | Understocking. 
III. | Moist climate. | IIf. | Dry climate. 
IV. | Summer months. IV. | Winter months. 
V. | Dense vegetation, as blady grass. 
V. |Scanty vegetation, as Mitchell grass, 
VI. | Absence of natural enemies of ticks. 
VI. | Presence of natural enemies of ticks, 
as ants, insectivorous birds, &c. 
The following diagrams illustrate the life- ; 
history and development of the cattle tick:— 
Larval ticks are capable of living, in some 
instances, for a period of over four months 
without food or moisture, apart from their 
host. 
fully matured. 
These young ticks attach themselves to 
their host singly, and not in pairs or clusters. 
Up till six days their growth is scarcely 
noticeable, but on the seventh day they undergo 
a change and throw off their skin, and are then 
seen with an extra pair of legs. 
From the seventh to the fourteenth day 
they grow but very little, and on the latter 
date they undergo a second change, which 
determines the sex. If the change should 
result in a female, she still remains attached 
in the same place; butif it should result in 
a male, he immediately releases his ho!d and 
wanders about amongst the hair of the animal 
until he finds a female with which he mates, 
attaching himself to the animal just beneath 
the female. 
8 
~~: 
NN 
SRS 
SS 
y 
“s 
aS) 
The pair will remain attached to their 
host until the twentieth day, increasing in size 
but very slightly, the female being a little 
larger than the male. From the sixteenth 
to the twentieth day the male fecundates the 
female. 
On the twenty-first day the female becomes 
fully mature, releases her hold, and falls to the 
ground; then crawls to some secluded spot and 
lays her eggs, which in course of time (from 
three to nine weeks) will hatch, and then the 
life-cycle commences again. 
After the departure of the female, the 
male tick sometimes remains for several hours, 
when he becomes detached, falls to the ground, 
and rarely lives longer than two or three days, 
lS moult 
The above diagrams are drawn lo nakura/l size 
Larval Kicks 
