Note on the occurrence of the North American fever tick on sheep


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Note on the occurrence of the North American fever tick on sheep
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Hunter, W. D ( Walter David ), 1875-1925
Gov't. Print. Off. ( Washington )
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aleph - 29651613
oclc - 27983895
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CICULAm No B1. / Nt-r 1.

iUniit'dl S.iies hi ,) rtim il I Ohmilii',,
BURKAU OF i;NTOMOL.fl'rFL4l ltt-raLLt 1.
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NOTE UN Till: 0411 KHk:MN I: OF TllH : N iUtl I I.Im Orb

In;y iu r. I. rdi hr. 11 't/ /I#., I' j',I' .iii. '

IThere are n pTilulisir lt ri, i'Ot ls 'If Oli 1lill, r .'- i ,. Miwii1 ,f li1.
North Anierir'in fivo-r lit k ( I., hIsill Inii ,,iI u.. if S.i\, I l '.li,'.ii I1
fact, it has generally iur.n -iippi,)t.u(l ltihit lii.- .lici'' (i1..- i li ,i 11 ,ill
sheep, althoughli Mr. 1I. II. l 6niioni h;as stiriiii.s-I tlhat suili iliight li.
the case.I In cunn ctiuiin with th, tiick i,,irk ,if thOir luriir i ,f I:-ii.ii,,l-
ogy an agent. M r. .1. I). M itctlirll, has rei uiitly ,Il't.iii,'l t. 1., lii, II
indicate a rather general i'-curreleit' ,f llr fehvr it k ini :.liii.p. )In
accountl t of the consiijilrille ira-tit.tiI iiipol' if tlii.i iiilttir il i-
f thought advisable to putilish thlis prelthiniin:iry iill',.
:: The practical importance -4 the dis, ,vry Ilma d' iy Mr. Mitrliill li.-
. in the fact tliilat the tilim tiii li l 'If ii,'k I, -li','p in1.1. i .iy-V :i %-T'
imTportant pearl in the work t tif r.iilic: ili i tail i.s 1iiio 1 intitr \t :y. Ini
the general work of tlit' rii.lii itioin fre-qtrii ln n1k" iil it Ii.ilc.* inf tile
starvation" plain untiler wliitli the ci'ttl ;1ir, rliiiriI fri 'iii jiasttires
for a consiiderabhle time. In i.iny parts of the lirk-infe,.?il 11"rei irilmos!
of the cattle raisers hive s n tnriVn t li, As InI,. iil J,-ilv c.lii r.rv i
their holdings. To he fortn-fil tI ilisp.uii with ti,, ii-,' if i p:irt of the
pasture area in nmainy cases ,nould forrt' tllhe ,f J:i irti-iin ,'f i,, ;:it-
tie, perhaps ait an unifavtirable time for inirktt!in,. 11if. lIoeve-r, it t.r
possible to allow some oilither kind of liv,' ,lt'k tio griz.i rin
from which ticks aire being eradicated iie,,rling ton thi*' st'irvatlini pl:1ii.
the inco'wenienre an'I possible Iis to tli, ri ihiinein wmlill i I. tii-ilr-
ahbly lesfne-l. Since he North Ameritrn fever tirk li.s lirrviiu.- i.y nt
been known to infest shep.l), it liM- h boprn ili.hught th pIlsirt.- i1ii,,lt
be used for grazing tihee aniniials. Thio,-vurips rriue I-y Mr.
Mitchell, however, indicate that the disseninittiii of feve-r tic-k. 1,v
sheep is of i such practical imiportatine that, at .least ini thle inrt- of Texais
where the matter has been investigated, a pasture w"Iutild ren.iin infeSt r'il
indefinitely even if the sheep alone were allowed to main over it. It is
not a case of the scattering of Ihe sed ticks frnii one part of the pasture
'Cir. 98, Bureau or Animal Industry. U. S. Dept. Agric., p. S, October, Is".


to :iitli-r. but a case of the breeding of the fever ticks on sheep, since
in several cases fully engorged females have been found on these ani-
mals, and they are now freely depositing eggs.
The f,)1,'%% ing are some of the particulars regarding data obtained up
to this time. The matter will be followed up by the Bureau of Ento-
mology, and a further report will be made at the end of the season.
In April, 191.7, Mr. A. P. Ward, of Jackson County. Tex., sent to
M.r. J. D. Mitchell a number of specimens of Boophilbis annalatis that
he had taken from a sheep. In this lot there was one engorged female
that deposited eggs which have hatched. Mr. WVard's attention was
attracted to the matter by seeing this tick hanging in the hair of one
fore leg. It was in the act of dropping to the ground for oviposition.
At least a dozen other specimens were then collected on this animal.
There were five or six nearly engorged adult females, together with sev-
eral nymphs and larvoe. The sheep upon which these ticks were found
had not been sheared this season, although the wool was rather scant
on the belly. Nevertheless, the ticks had made their way well up into
the thick wool on the sides of the animal. Mr. Ward notes that the
sheep was "as oily as she could be." The animal was one which had
been left in an isolated field for a month before the ticks were discov-
ered. In iwiiing the herd this one had accidentally been left behind.
She was e xceelingly active, and there were no indications whatever of
any disease. The only fact which would tend to indicate the possibility
of disease in this sheep transmitted by the ticks is that she remained
in the same place after the herd was removed. It is barely possible
that she was left behind on account of weakness brought about by the
disease at the time the herd was removed. However, subsequent evi-
dence from other flocks fails to justify the assumption that there may
have been any disease in this case.
Early in May, 1907, Mr. J. D. Mitchell examined many sheep in the
flock belonging to Mr. Ward. One adult female tick was found,
together with six individuals just passing from the nymphal to the
adult stage. These were on several different animals, but all located
in the ears.
At about the same time three sheep in a flock in Calhoun County
were examined by Mr. Mitchell. Two adult female ticks about ready
to drop to the ground and one molting nymph were found on these
three animals.
Since that time Mr. Mlitchell has examined ten sheep in a large flock
,:].lc~ngiimg to Col. J. C. Warden, whose ranch is inVictoria County, Tex.
On two of these sheep specimens of Booplili s annulatus almost fully
engorged were found. They were both located on the head, near the
base of the ear. Colonel Warden states that late in the summer and
fall the fever ticks cause considerable annoyance on his sheep. It is
necessary to treat them continuously to prevent damage from screw-

wrool,1. which are attracted by the i Imnd 1, ti when tihe tick detachets i
it-.lf or by the blood released whsn it w II,.,l.I- to i h cIIruhecI I i the
I %ill be noted that 1 illy 'ii -,..'- .1 speincimis of the fever tick have
vr been f 'lii, on smh leep .' Mr. Mil, lNill in three 1lilt, r, IT Hocks in as
nia3ny counties in soutirn Texas. It is expected that future oh1erva-
tiliens ill show a rather general oIc urrence on isheep.
Tl i'r, are several i,,i- ll- 'lI iiiit,,rtaiice to lite dlet.' riiiii I, a for
ilustnlirvt. whether the ,IT-i'riiim- ,f the ticks w% ichi have I developed o
%'luep tranismit splhe-tic fever when placed sin iioniinune ci!ttlh, ;nd
%li.llier Olw. slI "1' become diseaisei tl,]..i-_11 the .,f.ii. of the ticks. It
i,. tx p1t.,1111 that thle Bureau of Ani ital I InduIstry w ill indert ike invest i-
, t.itilmi' in tli. near flit iur. In .* i`L'i.' t tliese point. i I'ti, purpose of this
.ir.iilir is merely to call attention to iliItt rI if im neie jtc prAict i';al

It itay possibly be important to note that there are si ose poeculi:tr
fVt rt'res of the cattle-tick problem in southern Texas this season.
Viiriusm conditions have IIi.-'li unusu:Illy l. ,r., numbers of ticks to Ie
present in the ;.JricL. .1...rrilici2 to tlhe testimony of cattlemen the
ticks have never lieen more :ilin,'l,1iIl in the -prii, thath theyv are this
season. It is barely possible that this excessive ahundlance ,iyix have
had somelhing to do with the occurrence of ticks oil -I, i ,. aind that
under clilTerent conditions the sheep wouldd noit have become infested.
Nvverthvlh.-:, it must be remembered that in that portion of Texas as
well as elstlitre the cattle ticks are fri ,pi, iilty as numerous in the fall
,if tli yvr:ir as they have been this -iprihr,. In view of these facts it seems
evii lent that it will be absolutely necessary in plans for eradication to
exclude Iheep ',nm areas in which an l:it niijl is ,. iw, made to eradi-
cate the ticks.
Secretary of A.riculfure.

WASHINOITON, D. C., June 19, 19o7.


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