THE LONE STAR TICK. 149 
TaBLe LXV.—Longevity of adults of Amblyomma americanum. 
Number. ‘ 
Date Boris melted (OY Date last tick died. Longevity. 
Total. Male. Female. 
Days 
DUNC ay, L908 sere are oc,t'er,-'e.c 3 2 DVD GCL2G51908) ee cece eb eee 207 
STE} sed a U0 a eae 8 1 7 | May 15-June 8, 1909......... 256-280 
epi: we S008. o- Js302 1 10 6 4} Jan. 22-Feb. 18, 1909........ -| 133-160 
Sept. 26-28, 1908. ........ 5 1 4} Aug. 20, 1909, 1 female alive....... 326-328-- 
Sept. 10-20, 1909......... 11 4 Ma) Oct. 1e-Novs 4 (1910. 222 ose 2S 393-430 
ete fais 1909) = soe 2 6 1 5 | Aug. 18-Sept. 26, 1910............. 305-354 
Mr. J. D. Mitchell once observed this species in copulation on herb- 
age but we have no other record of such a habit. Ticks which have 
been kept together in tubes have never been observed in copulation. 
When unfed ticks are placed upon a host, attachment usually takes 
place at once, the sexual instinct being manifested only after several 
days feeding. Fertilization may be necessary for engorgement, as 
females which have been collected from vegetation have attached 
readily, but in the absence of males have failed to engorge and have 
died about a month after attachment. Males placed upon the bovine 
scrotum upon which females of other species were attached have been 
found in coitu with other species (Margaropus annulatus australis, 
Amblyomma maculatum, and Dermacertor nitens) even though females 
of americanum have been attached upon the scrotum at the same 
time. They have, however, remained in the position of copulation 
with other species for periods less than 24 hours. The eggs deposited 
by unfertilized females are dark and shriveled up. Our observations 
seems to indicate that only a short time is required for the fertiliza- 
tion of the female as males remain in copulation for a few hours at 
a time, then pass to other females, or return to the same female. 
They are frequently found mated with fully engorged females. 
Males have remained upon the scrotum for more than two and one- 
half months, or a month and a half after the females dropped. Fe- 
males collected from a host, if not more than one-half engorged, will 
attach to a second host, and if fertilized while on the first host become 
engorged in a comparatively short time. The minimum period in 
which engorgement has taken place is found to be 11 days, while 
slightly engorged reattached ticks which had probably been fertilized 
while upon the first host completed engorgement in 2 days. The 
longest period required for engorgement was 24 days.- The length 
of the engorgement period oes not appear to influence the size of 
the engorged female. 
