88 LIFE HISTORY OF NORTH AMERICAN TICKS, 
No observations have been made on mating. Very few males have 
been collected in nature as compared with the number of females 
taken. Making allowance for the fact that some collectors may have 
overlooked the males, it appears that females are much more abundant 
on hosts than are males. 
The engorged females are usually well covered with a yellowish 
waxy substance, apparently secreted on all parts of the less chitinized 
integument. This substance frequently accumulates in considerable 
masses around the capitulum and genitalia. The engorged females 
are almost globular, and the legs are delicate and scarcely touch the 
surface upon which the female lies. Movement of the engorged 
females is therefore practically impossible. 
LIFE CYCLE. 
Larve may live for at least 215 days. They may engorge in 4 
days and molt as soon as the ninth day after droppmg. The longest 
molting period recorded was 163 days. A total effective tempera- 
ture of at least 822° F. appears necessary for this molt. Nymphs 
may live for at least 66 days in summer and probably longer in winter. 
They may engorge as soon as the fifth day after application and molt 
as soon as the twenty-ninth day after dropping. A total effective © 
temperature of 878.4° F. is required for the transformation to adult. 
The length of the engorgement period of females has not been deter- 
mined. The shortest preoviposition period was 19 days and the © 
longest 65 days. Deposition may continue for 34 days and as many ~ 
as 4,706 eggs be deposited. Eggs may hatch as soon as 29 days after — 
deposition and appear to require a total effective temperature of | 
1,109° F. for incubation. 
All stages seem to be most numerous on hosts in midsummer, 
although we have specimens collected from March to November. 
Further investigation will probably show them to be present on hosts 
in greater or less numbers throughout the year. 
ECONOMIC IMPORTANCE. 
This tick has never been recorded as a parasite of man or of domes- 
tic animals other than the dog, and since it seldom occurs in great 
numbers on this host it appears to be of practically no economic — 
importance. 
NATURAL CONTROL. 
No natural enemies of this species have been recorded. Eggs in a 
bunch of about 100 which were exposed to the sun on the ground for 
about 3 hours all shriveled and failed to hatch. During this period — 
the highest atmospheric temperature was 110° F. and the highest — 
soil surface temperature was 133° F. 
