150 LIFE HISTORY OF NORTH AMERICAN TICKS. 
TaBLeE LXVI.—Engorgement of females of Amblyomma americanum on bovine. 
Engorged females dropped—days following application. Total 
number 
Adults applied. = 
2}3/41517181 9110] 11] 14] 15 | 16| 20] 24 | dropped. 
Mars23 19076 -4p, amt acces Ws Stee Recht evepege (are Soealeeer| ee 
Mar 22: st90 709 ra scm 2) Soi = eee | ace eee A leer atest Se aloe aes 
SSE 1S) LODDTE Sah DIN ee ce | oan ene eS ae Ae 
C9 Oot et OT et oD 
1 This tick was collected Mar. 25,1907. It was slightly engorged, measuring 5.5 by 4mm. 
2 This tick was slightly engorged (5 by 4mm.) and probably fertilized when collected. 
3 These were collected on a host but were not perceptibly engorged. 
4 This tick was taken from a host and was slightly engorged. 
LIFE CYCLE. 
Larve may live as long as 279 days; they may engorge as soon as 
3 days and in summer molt as soon as 8 days, a total effective 
temperature of 350° F. being required. Nymphs may live 476 days; 
they engorge as soon as 3 days and may molt 13 days after dropping. 
A total effective temperature of 657° F. appears to be necessary to 
produce this molt. Adults may engorge in 9 days, commence depos- 
iting 5 days later, and deposit as many as 8,330 eggs. The eggs hatch 
as soon as 23 days, requiring an effective temperature of 862° F. for 
incubation. 
ECONOMIC IMPORTANCE. 
This species is of considerable economic importance as an external 
parasite. It readily attaches to domestic animals and man. As its 
mouth parts are long and permit of deep penetration, the attachment 
of the tick causes considerable inflammation which frequently ends 
in suppuration. In Texas and Louisiana, where this species is 
abundant, cattle in particular suffer from heavy infestation. In the 
Eastern and Southern States man is more frequently attacked by 
this than any other species. Moss gatherers in Louisiana are greatly 
annoyed by its attacks (Morgan, 1899). At dairies milkers are an- 
noyed, particularly by the males which leave the cows and attach to 
them. This tick may attach in the ears and be the indirect cause of 
‘‘sotch” in donkeys. Mr. J. D. Mitchell has observed that on hogs 
this tick attaches by preference to the belly, where even in the case 
of engorged ticks, the swelling of the skin is sufficient to almost hide 
them. Suppurating pustules were observed on this host where the 
ticks had dropped off. Attempts to transmit Texas fever by this 
tick have failed (Mayo, 1897; Morgan, 1899). 
A correspondent in south-central Missouri reports that this tick 
is a serious pest to poultry there. The larve attack young chickens 
in such numbers as to kill them. He also states that the larve and 
adults are very annoying to man and domestic animals. 
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