THE BROWN DOG TICK. 109 
which became adult late in July and early in August lived from 77 
to 158 days. One lot of ticks which became mature on May 18 to 
21, 1908, lived about 3 months. Of a lot of 91 individuals collected 
on hosts on July 21, 1909, 4 were still alive December 15, 1909, having 
lived at least 147 days. However, a large percentage of the adults 
collected from dogs in the summer die within a month or 6 weeks. 
The longevity of the sexes appears to be about the same. We have 
observed unengorged adults crawling from between the cracks in 
floors. At Corpus Christi, Tex., they were found in considerable num- 
bers in the cracks of a porch floor where dogs frequently slept. 
Christophers reports that after molting adults crawl into straw or sim- 
ilar material and there await the host. 
Mating, which takes place on the host, may commence as soon as 
the fourth day after attachment and often continues until the en- 
gorged female drops. The male sometimes drops with the female or 
detaches soon after and goes in search of another mate. In one 
instance a male and partially engorged female in a tube on sand were 
observed apparently in copulation. 
On November 19, 1909, Mr. J. D. Mitchell collected a male Am- 
blyomma americanum in coitu with a female of this species on a dog 
at Corpus Christi, Tex. The mouth parts of the male were again 
inserted in the genital opening of the female when the ticks were put 
in a vial and they remained in this relation for at least fifteen minutes, 
when they were packed for mailing. Subsequently the female, which 
was partially engorged, deposited fertile eggs. 
Fertilized females were found to engorge more rapidly than unfer- 
tilized ones. In one instance a female engorged in 6 days, while in 
several instances females remained attached for from 44 to 50 days, 
and even then were not fully engorged when they dropped. It is 
quite apparent that fertilization is an important factor in the period 
required for engorgement, as in the short period mentioned above the 
ticks mated on the fourth day after attachment, while in the ex- 
tremely long periods mentioned mating did not occur at all. 
TABLE XXXVI.—Engorgement of females of Rhipicephalus sanguineus. 
Period | 
f 
| 
| Females 
Adults applied. Host. | dropped en- |. te 1 Size engorged. 
gorged. a 
| ment. 
| 
| Days 
NIE aos 2s = ots 2 a Oh Boe nes Det. .c 20 Nov. 2,1907 7 | 9.5 by 6.5 by 4mm. 
0 SS Se Sg ee ee ee .do Nov. 3,1907 8 | 1l by 7 by 4mm. 
nets ce ee | Bovine....| Feb. 17,1908 44 
I EDT aT ee Feb. 18, 1908 45 | 8 by 5 by 3 mm. 
a 2. SE RE eee eee) ee do.......| Feb. 23,1908 50 
= ee eer cee ee ene do. Apr. 10,1908 6 | 9 by 6 by 3 mm. 
-  S SE SE Be ee Seen, aed | oe do.......| Apr. 11,1908 7|8by5 by 2mm. 
a ae, 8 ellie SR ee eS eae a (ES do. Apr. 12,1908 8 | 6 by 4 by 1.5mm. 
Lo i Be oA RO ee ee eee Ae do. On sed 8 | Sby 5 by 2mm. 
