A predaceous mite proves noxious to man

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Title:
A predaceous mite proves noxious to man
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Webster, F. M ( Francis Marion ), 1849-1916
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U.S. Government Printing Office ( Washington )
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Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Introduction
        Page 1
    The mite beneficial in America
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
    The mite proves noxious to man
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    Influences controlling the excessive abundance of pediculoides
        Page 12
        Page 13
        Page 14
    A Western epidemic of the dermatitis
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
    Light thrown upon other problems
        Page 21
        Page 22
    Preventive and protective measures
        Page 23
    Suggestion to correspondents
        Page 24
    Back Cover
        Page 25
        Back Cover 2
Full Text













k'wd ;April 21 1 .I0.




U..'S. 1)-' AIRTM E'NT (O AG(;PRI(.T'Tl'RE'

BUREAU OF ENT)Mu ,I.o;Y-CIRCULAR No. 11-.
L. 0. HOWARD. Entomologist and (Chief of Bureau.




A PRI) ACEUl S MITE PROVES NO(XI( )S TO MAN.

(l)ldic Uidolds vc ntrfi.owsf, Newp )ort.)




]1Y

F. V E l'ISTE .,
In Ch( r e f o 't'rotl and F'rwp Ibtscn t biv ctiyal/ns.


























(UR .' 111" U O .\'1' ( }L\ (Y.


I-. (. HOWARD i a EIitolo//i( lt a,,i 'an Kf of Burn'n .
(. L. MAR.LATT, Isai.sfil EI ,elia/o!qit aqis 1,d Acti ( h' in h C f biI Of hi@f.
It. 'S 0'!,IFTDN, ELic'olir'c Assistant.
('HAS. J. (ILLISS, C'hiKf ('hcr:.

V. I. ('iHITTENIDEN, 1s 'haIl'p ( af truck call aln(] store ( p)'( f todu c IIs t i) rcstigations.

A. ). IOPUNTIs, in chaji'rg e S o/ r ,t i.1,'it ci pin Sl in IS littion .s.
W I IluNTEii, n. < 'fc' a/ /stioi/l /ir.l/ cropl ia, ii,','i in','stigtifln.s.
M. V[. W EIBSTE It, ill r If a a ,I.in ol i i ln't 1 (. stig tions.
A . QUAINTrANCEI, in (/ilic o/'l,/liiails frui fti 11 ia 'liijgation..
E. PHIn.LIps, i hll u',' f !t c ci altai-,
D). M1. { I{OLLA 1'. (i'ii l l, chi i /ary'c 1 ,ilioriil wor/ii .
MABEL ('O(I'OII), liblitiiai.

(. ]EA\l ANID IP 1iAO iE 1NSE(T I' N\ VESTI ATA II)NS.

IF. M i.i EBiC i I rii rc.r

(io. I. 1{EVIs, W. I'mlmLrPs, '. N. AINSLIE, E. (. i. KVIYlI,. J. A. HviLOP,
V. 1. \VXlI.miMITII, IR. A. \'RII'EYi T. 11I PARKS. 11 ER EIm T (msI IRN.,. IllILI '
IA'(.INBIIlI, '.,. a iii1 CJ'r Wrls,
tn)
[ r11)I
[ C1 .1 1I 1














nited Staites IDepartment of Agriculture,

BUREAU OF ENTOMOLOGY,
L. IOWARDI), Entomolokist and Chiif of Buc u.,


A PREI)A(EOI'S MITE IP.(OVIES NOX101 S TO1 MAN.


V;>, ['. M + W EII:)STI).v,
In '^ntj n/f t''m itfl Nt'i's l^^ '! nsi"''' ~ t.


I TI0I +CTI()N.

W hile the scientific ;i l Imedicaol literature of Eurpeatn co, nt ries,
Anti to swine extent of Asilia& (o ntrie(s, oll'ii, Ii n l>mtnerosll l'cords
of writes ottackiiL In;tal, it is 'illhiultnk .l"f Wri itel'. l fron t a p)erusail
A dl ub'nl^h s<,.hs r.,itfr,, si. New ort\\ )rN ort, lmovii in \.y
its I m ost activ(' foiir lf i b i JJr, 1. a-. litir 1. l' .'7
(viioic rniil in itli e attt(acks. lhv'r is o "o:'< -J. /
)li'ti<'llarhir reason \\,,li it h Ml t ot have -i liy* '
)ecom( e noxious to matt precisly .- anil f / *+I, "\ and.
el-wlwr, thian, in A eica, l e.Iauset it lI I as /
d(to l)t ihs with its li st i l il't, lhe A ltoUN ,i.-. /. .


ank ; h ve n Iinto it ot hmal) (m -

I rl I Ir I. W hile th'er i'i r (!de idedll si() lil. rit\ 'V '. o
I}el i dist th( t tcikt in maiIn ts it !r ,)li)i and
XXirl J i r- it I l i i~tle X ei i i I li-i '1. '



A iTm i a I lie \t i r -ii l ti iere\( ft tilsl .' -/
1 I *,+ \' f ,' ,r :' ,


whlt .1 iic ii-ae e ll -il at iican a d', I l e i t/ ... ti p, ,III ait I

m, s \Ii)ie w" it r iti < of i(d tiide N,\ sa rt l'(it\ii- ,
-l iar! lit Ic a ,i e It- m aiel ,' \ + a.,c it iis va r.\ ai, ii ...... >.,alt! ... ji,
veleh rlv to l) seen Ant) otlIr autl vcrv\ dil,-
ent species of mites have le in involed in atta k-, (d a similar r natIum,
both in tins (o)t trv am l in nrlu e. lere in America .iich tlroilles
Itir H IS]j


CIRCULAR No, 118.


1-twr I Apr i l 2 ;. IA1i








have until recently been commonly attributed to (,lii.'-'e '," which
inhabit neither the dried straw nor thrashed grain. The termii "chig-
ger' really includes a number of different kinds of mites, notably the
young of Trombidiumi and other insects which inhabit grassy and
weedy places and woodlands. This is why it is that people visiting
such places are niot infrequiiently attacked and suffer painfully there-
from. While, our kniowle(dge of the matter remained in this condi-
tion, thlie possibility of confusing thie disease discussed herein with
others of a muuch mi1e, serious nIatutiore was very great, but now that
we u1(lerstant the causes and know that these causes can be re-
moved, and(I thlie physician enabledl to distinguish it from an attack
of "Ii 0.l_ is" an(l prescribe proper treatment, much of this danger
and painful annoyance may
"t.r, be eliminated. There is also
S.- another point that must not
S" ; _be overlooked, namely, that
A thiss minte during its period of
:( greatest activity is almost in-
... . :visible to thie unaided eye (see
/ fig. 1). Not every practicing
physicians possesses a nicro-
scope that will enable him to
detect the presence of the
m u|ite, even when abundant,
h but thlie pustules or wheals
(caused by it are sufficiently
descril e I in the paper by Doc-
l ors (Goldb i-'.' and Scham-
Iei'rg and tlie one by ID)octor
Ia\\ [es to permit iof identifica-
tion. Later, when tlhe gravid
2V,,.-. (, ,:ii lfrI i:il,<,f /I ; O /r si tn'<',,. .d ( Ir.. ly female nite (fig. 2) is (is-
Ihl ii.'i-.l. ( [l i hil \w ii foI n I ]L +Ii .)
(ended(( wil h eggs anid young,
it is more easily (detected: Wut it is not in this state that it attacks
human beings anml is thus encovunleredl by lhe practicing physician.

THE IMITI;E B.ENEFICIA.L IN AMEIICA.
S) far as the alithor has been able to determine, lie firstM pub-
lislHWed rec ordf tlhie occurrence of this nmite in Anmerica was by him-
self, an(I was included( in a paper printed in the Twelfth Report
of Ihe Slate lmmtomiiologist of Illinois (pp. 150-)151).?' While assistant
I( Dr. S. A. FTor)es, state entoolog)ist, lie was (directed to investi-
gate serious iniries to stored grainl by the Angouimois grain moth,

lF'r a oii' ei. ii'n l ion <,f "chi rs iV." se (Circular No. 77, Bur. Enl,., pp. 1-6.
1, I'ublis t d in Traims. I)(pl. Agr. Illinois, vol. 20, 1882.
SI'i IlI |






.';,,#,,f ,;;,, c B others, of ( .iiro. VI*M\ .iiil sd li,[hi|) rs d,| \ ll,',t I were 1:1 tl~ l li:It I
exp, ri n.i ... l' ,' sidI cl t ii h t( r it, I t I rtl I I lI t I .';iv I I f It ll Ini I
inoth, HoIt ()IliIv +I h ir ,ht'r, illi hIh"\Itto 's niIt ;ilso iII l:t, r'_ s l, i .dcd
wvith licvhat to kdlip,)[o(l bv riv\(r to, Ne\\O ()t'I cath eisind tl licuc (,xittd
1\' s t O I I le r.
I I -was, d111rinII tic invI-st i(.-tiw-v I oIs lii; IIt Is i mito \i,;Is dis overed

t 11t 1 .1 i l I In Io It le It(;win tx to i. A s tl 1 o' I ,t i 'i | p ll t it ion
I 1i c l .irii... ( I o )- ti li r's ,lts11\:)itio i px'coitiit ritor Iii l i Soi'c
dili[[cult to o},tiiii, tliuit F,,ot(tion t+rc lin tiii'+ to llic' owc ttrriic<, of llhis
nmitle is given hrewit1ih in I'ill":
l',d'l't l d,.t." s fI ,i ,, ro ,is i i I,+,,lo iirio.oi-i ., NX (>.p lrlp A\l +o, lllh( 1 h11 f 4 l) a s+ack (if w nh, il illf .+l+il w il li Lir.'v; 1,f 1ln, L+rnr in 111"11 1 :t.~ cc i\ i) I+r++T i .a l1 1111licrtl
Illinois, which, fIor w\"iIl otf li,1'1 W;t- Pill .iido for ifilirc iti.l~p<, iinn. (hl Tih IL ;th


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+i, l.tl"'\''. it! i'rt i t o f w, lii*;! i : + c Li \ i; i!, |~ [ ID
1, + ftIt t't ,~ lJ++; # l i


of N iov tmber, wlii c (t l liiliiiiit t iwt L','.ii> ', iiiii i ;t I r\ ;t .
fifty, threoi in wll i l i ln l \+irii i + w ,r y llow ,ttiii j t- [ hici prv d 1, ;1 X-| i t t II' 1 .i. I ',
COSIM Nli w |li rllt ll i> wil> n tI ilin i 4 l h i t, |i l l t i i 1
lil iti td lt i uni tt 11 liat In < ttli r it _ liX lit :hit I ll-i 1 I ni l
at tl li tl ii llt'- u I i li t ,it I l .ii I ><'\ i it li '4 l l l i t i ti ]t i t i It I



<'Xt liil ili l ot, 1 0 i i il tl ,t >[il. t I: l 1 Ch 0ll' 1 k I h''.t n l h I I
I. r irl 'I + I ',I tI .' i il I1 lh I ll>llllt!e n]. im 1li~id 11 *;ll*) n *dtil.it lhi+.- Iinii, \s ,1 kn-. tl,\\, tn i >
in bll i h+ l/ ':'.]nu l~ t nd nil ]'+l n+'r .+iiic n iim: lI,+,ii lir-i dirn rrrd.,, tr
l ilt+ tl 'lr- +1 n l' /I Illl ip i r l l-i I+ i', l',. +, ( llr, lcd, ,ll (,1i \ r .l\( I I. [I'li
y ]liiin lll],l ii d r H. ~ t-. p ttil n' litL I h il :>l~., t,,iri
1SI.ST. .ilil d,"c+rili.d ,l Ix
I' +il pl/.hs]if/ ,lx tu If ill lhi t. :Th tl+fllll' I+11!- l'ni l i, il lli, t l r -i- ,l
SIM''citl -l n +I It' ly i(ncii, ,f I> l~l~ vlr tid~r t i ,r I q'rl'tllli\ '*id r. oJl
| ('ir. 11l s 1


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it t It itt I ttl t
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, i i I l',i,'d i ll- lit t li t

I p r( ll l- t i ill


in hl. l r<.,t l ; i i L'o
' 4 -|" tiN' I.,pi ttli .


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i K H '^31 j -x -*(lA,








If it has been found by any other persons than these, or in any other parts of the world,
previiiius to its discovery here by lme, I have not been able to find the fact recorded.
(lin IDecember 31 and January I, I examined 100 infested grains of this wheal,
which had been continually kept in the laioriatory since it was received, and found
32 lper cent of lhie worms dead. infested ,y the mites.
While making these examinationms I freutently threw tile grains containing infested
larve, into a shallow glass dish, where tliey remained on my table until the warm
weather during the latter part of l"February, when the tenip'rature r f the laboratory
at night was much higher than it had beoen during the previous cold weather. The
effect, of the change was soon plainly to be seen. The comitents of the dish 1- ..., to
swarm wilhli newly developed mites, and a larva drlped into their midst was ime-
diately attacked, and after that its life was of short duration. L.arva' placed at some
distance frinn the dish suffered a like inf(etion.
To test the tiatier I placed near I(he dish some weeds, in Il(he pith of which some
larvx. were hibernating, and in twoi da.ys lhe mites had found and destroyed them.
These ytung mites whie first not iced are very minute, of eloingate form, and extremely
active, running alout in searchn of la rva andl when one is ftimnd they immediately
pIUlllncur tle skin and suck tihe juices.
In a la or two the lIost-erior sego'lnuits (f the abdomen begin to enlarge, and this
process ('iiit inues until the inflate'l, blal(lr'-like abdomen becomes l(en or even twenty
times tihe size of the cephalothorax.
During this time they have gradually lost their ambulatory powers, and remain
stationtary upon their viitinims. In the ilmealitimle chalngos equally wonderful have been
going on within the abl)domen.
Eggs are otiliinually forming, and within tliese the young mites are as continually
d1.. 1..'i.,_ passin ig through their entire metamorphosis, eli/c'l iiclidrs fit acquisition
oftfi jow-lli pair of 'hjps (an exieplional chlarac'ter among miies), wilhin the abdomen
of tlie mother, from which they make their way as fasl as thev reach maturity.
The feomals are quite pip ii, I have huntedd frlequently from t40 to 50 young
and eggs within theI abdomen, alnd live lltl tlhiy produce even more. The mothers
survive Ilhie bilth of a large number, if not a majority, of the young. The male I have
never foMtl, and 1 am int(liNS I t believe witli Mr. Newport, that the species is
p:arlithog'nious.' The minute size of th(ise yo,' ig miles aduilts of their free access
to tihe larva ifl thi moth, through tlie veyi small opening where lihis made its entry,
and a sinMgle mite with ils progeny woiul bI t, il. i. i i destroy it.
That bhis is very Ioftei the mtanlter of attack is proved by lieh fact that grains in
which lthe larva is badly infesntled frequently have noi tlerl break in the hull by which
even aying mile could gain admissiim. Iike tlie larxva' oi which lhey subsist, their
develiiomeint is retarded or increased bv Ilie timpleirature, tihev being quite active at
a telnperatlurie of (i0 V' lin it i in ilde'r weather a Wle ti remain within the abdomen
of tlihe parent fr months in a dirmni sl at., awaiting a rising temnperature.
While, as stated, this was piobatly the first published record
of the o(ccurre(nce of this PIedic'iloides in Aiiii i 1 lie writer hias
sin(,e hail rt!ason to believe lihait it was e)l'('s('nt inntiv vyeal's prior to
this date; aInd, idee(l, in I he light I infiorn'ation thai was obtained
during lithe past year, 1909, it see(ims together probable that it not
only o(''ccurr'ed )but proved noxious to mian, in Massachusetts, as early
as 1M S(.
Tie particular reference, hio iwever, to whiAMh attention is called
itan be I'ound in tlie Prairie Farl'ter for lhie vear IS-15, page 216.

SI L iaxn e tjserved lthe inale, though (IIonly occasionally.
S(Ir. 1l1S1






Much is herie uade f ld.rvea attackin (l. tie slems il' whuat aolivXe the
Uplp r |(l i amll l I il III ll c l 1 011t i tl ler wite 4 lll Ws\ thlills signifi uatil t s- n-,
t(e + ": III on e ine tance ine __i a n v w ere w Boun inl a sin hl stAraw, )I'
of which had just liatedil l." Aisi. ill inan tlh rjuii nl, lie 'iIi w are tll
that, specimens o il'e.te st(i ra were forw\arded to (the ountr. V
(Gentleli an fri i. ipioville, N. Vl., ien M Y.7 which l thile sendl r stated
uontained e_-_-s, hle sides laive ndil l [;,e. In oth ealises tlhie larva,
w'ere allm st 'lt a xi l A ,4olit tlhse i l i e g eaim eril hlatel-stel maL ;la ot i
( fi, IiCt iiy lli+i am 2,twu i I l i. A.cr dn X 1,V tI ML y (\\I ,Mservaltiol, liet
mites at tack tie l oie i\; of M orinI i.:ii 111 r;wtn, in stll ,i f wiheal, andI
OtI, C i lain t lfail to l re struck 1)v the cle, arrest s \wiith which t et slate-
l'menlts just cilven de-cribe larveo tot11i6s Sp4e'es in the sterns (of gl'n in
or :-i I'--s bvin attacked lby tiese lnite2 thle Iri'vid 'e ale o' (o lh i hl4
1is every p eara5n2.,e to (lie uinailed e e of aeinX,' i initle '. It
tlierefore seei s not r i pr mltle iti -l nii.i e I wa a ot ,d ver tlhe
co iIItrv it tl ie earlier date, IS1 5, \litich'l i uld ani t ati e t i I)v se 'eril
yeal's the dehseriptiomn of tile species in ln him' l a byd N>\\ewil o'(, win)
calhlel attention to the oc urence if tis mite as a larasite in I le
nests iof a wiil low (Anit liti/ lixii 1it i .., i 1,. X i in a lpa vr redl Mawll
5t, .5),. Before lile laitnaIati S iet i o I' [ci lotd n.(o
In (iie account thie kn tbv |). T. \\. Harris ill tlne secod edition
of his "Insects Injurioi s to 'eetation." in co'innectiotn with bis
discussion oI' th Ie Va tlv o' Irri'en es o" t le balrho- jirt l+ ,'nii (1.,mo,+,i(Iil
hin until lately puzzh.led tlhe \viter gmeatly. (hi |)aie Im,,. edNition of
1852, le +says:
In th t. SUI IIKTt ti, l t- Iit, iii i il h,- l li








I I I( ,in neif's l
found alive in vtraw IN OlI- in I Ihiu,+, I.-tir+''. l}ti t ,-lv a \% n, 1w,1r i lAi,,-I ['+',inll lw l i;,lh
Ithe y<';r i+ r,. W\k ,imiii ;l At qWtntl t ilhii larmoih+,lc lN o 1l 6-r trimil vmh-- nr }mwltnr,'<
',V licrc w n,++l I tI~ l + nia m t ,,+rr. ,i-1 .'rri fli l' ;>tllirl,+t l +,+,+, r irt';t--iiiiiri| 1 +', I lir, liili"< il' ilxt "-f
fli+'" ; all< l it is wt t hal 11". !Ir r i \\ l < n<,I l" A xilnftili, !.+it l A'riulli t,> lW)r itli' t' ci
W ith till(, :ain i t.. +,0rrr- i..'rnr all+.I hulritn .
T e'l"e s,-econl revmfere occurss oM liIe "f tile satne volume, in
which it is statd tlhat "'alimmit eigilt \ears y arx | wlichll \ tilh l be almost
18S4-11 sine ()f thi'se in tn 's laL;il r1 *el'trrit^ t thle barl h v joinlt\",rlllI
ahat liad cote rI S m a st raw lei I in (';mi l d'l e w ere sl io\\ It n lt lime. Theyv
huliad ,pro n v.+\ tIq rou!ld soito iii l + W I Slevpiing on1 tlie 1I"4, tlieir
Pites or slips Ixe+iin follh\l 1>\" by oii.idehraldle inilaliimal lol l andl irri-
talti n. wti le 1 last eal davysal .l\V So ?Q) umer"+l ols \\, e e Il"e isects that
it was 'MoInd et llccesatv t, ('1110vl ik aend, no! tmrn thIe srw\.+-
Not,, tlie w 'iter it hIas ak v, bA li ni jmzzliing that thIe adults of
tlhe barley jointwoirm. asl they wr'e hdecribd by lwo"to 1111r1i-.
shmouldl hav e e le lo luiteu llaid tu l i W ltikl.in, and catl-e t he
'' I I -A [r)i i, iuln li.-li l in n rai., l iiiii Si n l t+ i lb ins.+ w",>im
[O *i r 1 1ts)1







eruption described and yet not be able to gnaw through this cloth
and make their escape, as every one who has reared these insects in
('cofiinement Ias witnessed their frantic efforts to escape as soon as
t hev glaw their way out of tlie straws. The mite Pcdiculoidcs vfn-
lr'icOsd sl now furnishes as good an explanation of these attacks
referred to by Harris as we (can expect to secure, after a lapse of
three-quarters of a century, with no possibility of obtaining actual
proof in the case.
In ISS4 the writer found this same mite attacking and destroying
lthe wheat strawwormi (isosoma fqramie Riley) at Oxford, Ind., and
in speaking of the occurrence of this larva and its parasites, lie made
this statement:
('uriously enough, during the time it occupiies the stubble in the larval and pupal
stages, it sometimes falls a victim to the miite I'dliculoidi(s (l1,'eropiis) rcntricosus,
whichli enters the stubble from above after thle grain is cut, but whose sense of discrimi-
natlion is rather poorly developed, and it is finally victorious over the Isosoma larvae,
its parasites, and thlie predaceouls larva, of Lptolratchilus dorsalis.
Thlie same year, and in the same locality, this mite was again
encountl ered by the writer, attacking tlie greater wheat-stem maggot
in wheat straw, and thlie remarkable resemblance of the gravid fe-
males to i minute (.--_,' was :ig;in noted. Since that time this Pedic-
uloides has been reported by Mr. E. M. Ehrlihiorn attacking the larve
of tlie p)ea(ch twig border, Aiarsia Uieatcla. Zell., in (C'alifornia.a
The same year Mr. Marlatt reported it as attacking the eggs of the
periodical cicada, Tilhicn S p tfinljcim. L.b The same year Dr. F. H.
Chittend(en'" stated that this mite attacked tlie larva- of two species
of ibean weevil (Bruci ;s quadr'irtacwtitus Fal)b. and B. cimnettsis L.)
and destroyed tlihem, often in great numbers. Still later, inii 1'i4,
M .-rs. 1). Ilunter and W. E. llinds, in Bulletin No. 45, D)ivision
of Euniomologv, page 107, called attention to its attack on tlie larva'
of tlie (cotton boll weevil. In 19OS Mr. WV. Dwiglit Pierce'! stated
that itis mite is a common weevil parasite in Mexico. In the
samime putblhcation, page 42, hlie ('cre(dite(d it witli being parasitic, not
otnly oil i te cotton boll weevil, Atithoiowtt us qrantdis, butt also ott an
allied species, thlie pepper weevil (A. cuwt iu Ca(no). D)r. A. 1). lhop-
kins informs tlie writer that, in his studies of' forest insects lie has
enco('untlered i at iil iti.. the larva,' of wood-)boriing beetles, and at
one limhe, inl West Virginia, it ('aused considerable miortalitv in his
rearing ('ages, where lie was attempting to rear wood-l', iig: longi-
('Cor'ii beetles (('eramibycila') anid l)arkbeetles (Scolytida), precisely
as experienced byv M. il's Licliteenslein in Frantice.
a imul. 10, l)iv. Ent., I. S. Dept. Agr., p. 17, 18S9S.
> IBil. I 1, n. s., Div. Eln ., I'. S. Dept. A-r., p). 101, 1S98.
I S. D)epl. Agr., Yearl)hook for "-',, p. 217.
d BIul. 73:, Bur. nt., u '. S. Depl. Agr., 1). 30.
| ('ir. I 1





In U(p, publicaion of M,-ssrs. Hunter and Illinls previously rn-
ferre14 to. sonic intiormiaion is given relative to al attempt 1to use
this mite artificiallv in overcotmin- the boll weevil. It hlais b)een ex-
lwrinented with quite e.xtensi\elv Ib Prof. A. I.L.lhenrera ainld lhis
assist ants of tle M(,xian (omisninsiou of Parasitolo, and upo lbii
retirm fNoun a trip to Mexico in the l'f;ll of 1 )2 Mr. ]ll clir l)i.u,_-t~l
with lilni, ilirouih thiv kindlloss ofl'Profssor ] rimre a, stilply of the
parasites, front whch otiiers were reared fAr experimennal work in
Texas. This ex!erimeni, Iowever, )wiin, to cmidiltions beyond tile
coatrol of nall. appears, f(I'loriavlyv perhaps, not t1) have reIslted
satisfactorilV. "n, olf tlhe prin'ilpal obstalhs in Atis Case seems I)
have been tatli where tle mites succeeded in estlablishdin, Ilhemn.selvcs,
they weres" timu(penfly dest royed by thlie at lacks ol'f sill anits.
These references show quite Anhearl tl(e wide dist ribution olf this
lnith, throighoit t(le I united States and its lriat variety of host,
insects. We hiae,, in laer years, omei to \((onsider it a verv uslseful
parasite and ()io(e that is likely' to att(ak alios anl 'sot-bo)(died
larvia to which it (an gain acce('ss and be secure froti otwer lmrvdt-
evtous insects and advese, leteoroloji(al )ondit ions.

THIE MITE IN)IV)E- N()XIM).ir TO MAN.

As idlialted in the earlier portion of this paper, either this or
somni other losel rallied speies s liow, been kiowii () ()t'ccasiouna~ll
attack an and:""f ani al s in Eur( e)(, wlen tl ese art, eifi/a( d ill
1I iii'llin,_ or comei into colltaict will Zrainll (r straw infested bl their
]lost, insects. Tlhe (irst inslanctme of this charammer (o be noted in
Aeil(lrica, however, has been co' ii"ncated( to he writer Ay Dr.
Ihenrv Skhiner, olf Philadelphia, PA. It was alou Ilh lie r IS'K!),
wlhilh Doltor Skinner was pral ill.. medicinehi il Phladeiphia. that
tlhe owner of a homrnilin Win)ue in one A' te le New Jcrsw\ suhurhs ()f
tihe chiiv came toi him in greal. disiress, .A-inii tHit K(l tenant ald
keelpr of tle boarding ollse, whi(h acomhimodated aMow seventh' v-
five persons, would no')t pay the renit thir(oi, ndi further shoed tihil
thle tenallt had been threateed willi \6111 l pimeedins In th(e bo)irdnl-
'rs w, io h a d e v e n n _'.. ti( b ol dily i iju ry T lih e oc asi on ol' all this
trouble was an ephidhei of a rah ,hhke disa (Ilhe causs of \which
were suspleted to reshhd in th(e mat tresses (of the beds occupied b Ille
patrons ol tile house, because the occupainsi had been atiacked lv
,L verve ymysterious and ..'i.,vatin skin eruplioln. T1l, o)wHOer s'-ub-
Kim ted straw dust and inttiess debris taken fim h(ie suspected
W)1,I and om xainali tio of itids Doclor Sk.inner foid specienis -)f
this iite. The hoise was Iplrompily des(erte(, bv thle oarders, nlone
of whim. at it seeis, escaped infection, ndip ntowe of womn Wit-
'.''- i '" ,'ir. /Is-.. 1 -- ,






willing to return. The matter does not appear to have been further
invest itat ed.
In 1901 Jay F1. Schamerl M. )., of Philadelphia' published a short
paper calling attention toII and describing "An Epidemic of a Peculiar
and Unfamiliar D)isease of the Skin." In this paper Doctor Scham-
,erg", who, besides be-
ill a practicing physi-
cian, is professor of
dermatolo(,y and infec-
.. iousl erjuptive diseases
"."Y. I SnI the Philadelphia
.+" .'--. ^\ P(,olvclinic, described a
,;,. :' numbi)er of cases that
Ihad been treated by
Shim a feh w weeks prior
.- to the )publication of
h, lis pler'. TIe erup-
tiol and its effect on
-. *thepatient were briefly
d" v..ecribed anld illus-
+.:-v. i rtedI, but the causes
4... instrumen1cltal inl~lhl I-o-

.g.about theseattacks
,/ ' .,-. .. w re stMl 1111 nown to
-, '": .'L. hi11; and, as several
',S:4 *.' "- '"einl)ers of tlie same
~... ... .. _-"'( hliouseliold were com-
11101, v aftec',., I. the diis-
+. -' :." ",,.'.N:./ ease was considered
M."i'*;": "- "" : likeiv to prove conta-
'"' :i *:* "...- /.f ,'1 11i I's. T' le derinati-
*\ ". ... o. a " tis, liow'evor, was not
'\ "^^ c''Aw/ to,-( silit, of, and ii a
", " |);a)el.r contril)iited to
-J'lte Public, Healt Ie
|)or(ls )Dr. JoseP) h Gold-
Fi(. 1.- L esidii m ; (;ms lcd >Y )ites of the mile ilaichi idi i ,icosl )(e r, ).. se l ( ista t
In t Iis c io t IhI' e rit|plions "Ire pv ctsi cl y Ljir e, tlis 'er-like', and -,is ista t
Sl)!pa.se-l.v pl:,c.' llrc,;, n; SUI'N eOll Of tile U united
p"'"a" a ""f 1w .""rs States Public Ilealth
alind Marin-I e hospital Service, ili cool)eratytion wit h 1 )octor Sclhanil),.' .,
)pub)lislhed t(l'he firs, exact information w\e lave relative to tlie cause
off the-se (,p)ide l'hila. Me Jli .,i) J uma il i'1 r July 6, 9)01.
/1' tl1ic l .ihlhll ltei))rs, vol. 21, No. 2s, July 9, 1909.
I C ir. I I I






ftlat pulblication il ll is conltrY in wll ich the ;attIck ol this milte Ias
been folhlxed 1u p t ila ils deri al,11diwrical elJ'tecl on l ,liiii a il b1 ing c'are.-
fulvly sttudied aind described 'Tlis j')tler )f DI )( to[' s (itohll)'t;l'di ( r and
S1c1 I:I b i .1 i aI ma.v be brifrie lv sm malll1l ize(1 d ;is1, folowu s:
In (the 1. i,.," ,and stll ner o1l' 11()9 t(liis peciuliUr eruptive disease be-
(Ctiliel (l quite )l'('\ alent in ] lihadelpllia a.(d vie dI tlIri II, (own\sII A\u IIIt-
lbreak anion- 20 sailos upom i private \aclht dc-kd] in it.h Dhlaw:are
River iittracted it(l e atteli it( il' ],(I tlt the citY aild thle f'de'ral health
llthor'ities. The S> t'- .. ...
gen-( nlerial of thlei
Tnilt~t SH(V,tae PUbilic
I leilth a nI Marine-
Ilo lil 82-1 SeI'rvice dehe-
lnttee Je)i. J c 1h1
Co~ldbtetger, pa".'>ed{ is-
si s atit sl o >'ew lk, to pro-)i
Cfire to th lti'h ol) t ia( "l




for the the pitle ae 0 f






no,, sleep,, po It~ i,,e new a- trse e ande tiel reo' edsae
ft('ri'e ihx eallie 1 h .

t2, j ate elor, 6 1 t1 "a 11 a.l.





21)ti 'ti whoat li fad r e
b1e,1 n Seiit to a hos- t e Vh .:
pital, 1 )oc r tso (i'H-
lbet'-c"all{ Schlltlbet.r "






v i s i t c d ti" I x le ( Y at1 "~(I tIih V.~'ll Il''~' rh d I 14e hi
wldhenc the IVcllli andi''{ "" e
haI a e lt 1-4,48rchill ax- d.h








11161:1', I Idoll lth t"e xxee al re x 11 Ip hj(1 il ia
dn int ,I i o ,II t}IT ,,im rd,

Their It tx (,nitt le W t i a xe
directed to the fit




t iI v( t o t I I <, ( ,\ v e I u I )I h I( 'lep t t It 1 11 1 tl' l : t Itr ss < r I ad I,{,I' I thI cirI
c lo th e ., t11l> ) l th e m E';h e ,cl (d f cl+ ",' a {lld l~ w l ib! e rl+ d T he' tl c re m w h o. d{i
illo Sleei p o, 1 1)( ,ll ,, ma tews relnia i, d cl t ltt re+l frve,'(d th dl,_W.1<,+t0.
A\ t n b o u t T h e' s a lt i c p l -Iri, i n h1 ( w i a t l ( M t \ u : 1 r 'c ,*4 i N ( I + +cm t tic l- I I I ;' I I I
e r n p t i v e. PlI ,(1. > r V ; Jt i i n V 1 : t1 + ,11m -tit ( + ( df I m, l r (t h el r ] m : & ,-

thll 'It hq)it-, had. ak}o rec<.eiv ed newv straw,, t11:11 wid rfu-,+. ~ .! rtlhct-
lt1(ore, t11t mtlY, Il},m+e ',,\+e at':tac:+,kedt N,\11) ,'-hle t upllo th~e Il+lattre~sesv
or ()th(e\l,'\\ ("is('ce Ill colitact with+ thtem~.
{(Ir C l%11SJ







In addition to these ctses along sailors, Doctors Goldberger and
Schamberg exa(\ ined or received autlwintic information concerning
sevenIty othlir cases of this disease occurring in twenty different
lihousehliolds in Philadelphia and its vicinity.
In practically every instance they were enabled to determine that
lie patient had either recently slept upon a new straw mattress or
lhad freely handled the same. Where only one person in a household
was affected, it was found tlat hle wN as the only one to occupy a bed
supplied witli a new straw mattress. They were able to trace all of
the incriminated mat-
tresses to four leading
I.mattress manu fact iur-
ci;ers. Figures 4, 5, 6,
and 7, from photo-
Sographs by Doctor
,7 Scbamberg, show the
condition of some of
F -'d'i. :.the victims and illus-
upo.n'': .' atrate different forms
s...., o lesiiof the eruption.
t .Careful investiga-
t ion warranted them
,in excluding from con-
t ot. l si(leration the ticldng
of the mattresses anIi
the jute orcotton top-
ping contained there-
... i. he('a5use of the
disease wxas, therefore,
circumscribed to the
straw. Repeated in-
-. ~.-" (Wquiries elicited tile in-
F caused Ib% 1,ires Of t he mite tP i b (Wicosls. form action that all of
ILL his figure 11h0 eli0tuplinS :roe st ill more iiminte. \overingI Ole t 11 e litaiufaict urers
entile t1"dy, illi hlding lhe lii l iud tlelck, the hati. h111\ been
reliu,,, l rioi the niec lo sbho,,w their di JuIA o,,l,,,l I , ,L bOIL ,1, of hal received, at thle
the hcwl. Thie hc.i,, ii:i., U :,+, less u i N llorlI ha, l own, ill I,> :, .i 5. time t lie disease-pro-
Ilucing miat rres\es were into Ie up, \\heat straw from a dealer in
Salem ((oitmlV, ill Soutlhi'll New J(\FerseY. One lma'lintufilcturer had
itsel I straw from Ha is 1 source Oxcilusivelv in t he affected I mat tresses,
while in atiolther case o lie s raw ha.d come from soutlherni Indiana.
rldI*; ti f(I /)t(lIraU.1ti. I)octo)rs 6ohdi t,.r-:,.r antd Schamni erg sifted
tile str'w tix'roii a niitltress tli,,,1i-l, the nineshes of a fine flour sieve
upoll a piere oie('e if Ihite glhtss covered 'w ith white paper. (Close
scrutilny of, tile slit'uths nleh'r str,,12- electric illuiinlination soon de-
tectdl som|lie -lgiliit liiotioll. Tile ju(iving\ particles wyore touclied with
[Cir. Its]






a needle moistenetd in Nl"eerino :n1d transferred 1o na "lIss slide.
Seairch Iwith the Iliros I opae ) iChWfl (sek the le-s I wnie of ;i l mite Iif veryv
minute dimensions. The mite Na1s identified ', lithem bY Mr. Naimliin
Banks, expert in Acarina of' ,le Bureaiu of Eloomolo,-Y, [lited i Silaes
Department of A.-._ I ,'l(ure, :is very close to, if' not identical will
tlhe l'liu <)tl(.s' i'< itfric,.,'u.s.
Inl order to demonstrate experimientally ie( elioloh'ical relation-
ship of lhe suspe ,e strayd mattrelISes, Doctor {,oldl. 1 -. exposed
his lbalredl left'l arm and shoulder' for one hour bet wecin two :mat I("sses.
At th le elld of 1lbout
seiex t een h iours a 1111111- 1 "'
bierp f chiarnt ie ersti] fi L i,






lesionft s i p ") a red i poIl


the 1111' "11) tl t itlll, a i d .
C lhest. Lat'e', f ilt'( (,
Volutllleer, slept~ Ilpl}il
the n tles 'I ndil
elith of dev'elopd'hi1









t'le arua tionf i tleft











to tlit' vapor o{ thl otroform d .l a I i cI t I Hiti ai'\
insec(1 of a carin Ila tid I~ pIse t Ilc' e'lli wer I lie
plieriod. t -. ... a





















(lt'StI nt create il ilt "'il ii '"' li t' ~l~oeen ;lllet 'I \ 1' lt rlildt liiiii e\l~ l idcI'llv
des }{tro e in thl,,ie si-ti.r .l.. ie i li l w s p o i 'iL le e i[io i











for no l esi) o s ll appah d afttr tlit appl'atin ol' tieilito rl ti
sifted straw, divide
it inlo two p}ril .,. "
1111d lhic ed I t in two
c'en I eai e t I ri I as s ...
dIishe's. OneI (),* these..w>:

ho}ur to, the{ left'l nXIlla..m ._-
of n / -()Illlt ce rq A t tIll he t(. 7.. loPion,; I. bv I, i I ; of Tho, m, ,io + 2;d << h<,/
Se e n ee ll uI th e 11 .. ... > ll f4 > { i fl{ I t <' 1 ]cll '
{'I1{I~~~1 v, I{}i ,i, t{{nI{
{th it raict e 1.1"t Iv c i11} perl I... : p- t ]{
ti{}n w n, prs P es{ il Ill .:k, rr, r, ',, ,'. , ll,, ;!
t h e i l'In l ( 4 f t h e l e ft ,t d" > "
aixill .1 to hichl the Pl{ li'I lidll (d,1 sll~\1'a .-ll'til' ll~ I}'t I I 1,,,,!
T h'le seco{l lId p } .1r io I Io {t' hIc s II-:IW \v IfIt Il _'- I n I I I I P( ,l. -l d I I, I},{
to} the vap> r o}f ch]lo}ro}f'onr u n o ili zi i 1,,wl wtrv ill 1 \ ic\ 1(, \ I j, r .111\,nll
insectl or actr'tlIne{ flint lii'L,1il b~e tpl'e-w~il. T1h1c-,, \%tclilc I I' hlli
app~llied{ to tlhe lri,-it nxilli {fd dicl -q/lll \ ,hm tlil t,, 1) N% h,-- left', ,:Im ll
timl untreated] sift~i,'-.- 11:l(1 1)(1011 nppli''l. Th'le c\t,',tri kh ml lI v,
dlestrovcd ill file hifliwi s tile liftillll it 11, : i- lr, ;1,; p'oh im Ille c. p I'M'i ,>i
fori n l el hsi~ilis :I pnri},ledl after thc ;iplpli, mttn )I* tihe chIl,}lwoftnl'llzed
sift ii,._-.
j {ir. llS]







Doctor Goldberger, further, removed from some straw siftings five
minute mites, and, placing then in a ('lean watch cry-td, applied the
crystal to the axilla of another volunteer. At the end of about sixteen
hours following this application five of the characteristic lesions ap-
peared on the area to which the mites had been applied. (See fig.
S, from drawing by F. II. Wilder.)
INFLUENCES CONTROLLING G TIE EXCESSIVE ABUNDI)ANCE OF
PEDIC'ULOI DES.
It will b)e noticed that Doctors Goldberger and Schamberg made no
attempt to discover the underlying causes for the enormous numbers
of these mites inhabiting the mattresses involved in their investiga-
_____ tions, that problem
... coming properly
within the realmn of
..-. '...,. _.. entomology. When
':"-. .. the writer took up
.:-. .. .. this sulbi,. t. with the
.'- '".. view of finding out
'*,f 'the causes for such an
abundance of these
B ".. mites, 1)octors Gold-
., .....,.. .-.- ., bergerandScham berg
very kindly placed at
--------- his disposal every-
Fl, "s thing( in theiir posses


A : l:~u .aua -,r
Sion relating to this
epidemic, including
"' .. the mattress wNhieh
S. D.'& i)octor Goldberger
had himself utseds in
FIG. .--Lvsioiis caused hy bites of the inile o Mdirlodis w nfrico us, experiInents with this
XtjboUt 1111 Sii ;i t. lm ite, carried out by
him at the Ilygieic ILaboratory in Washiniiton. Doctor So Iihinii1crg
was (equally kind in placing at his servi('ce all of the material, notes,
ald p1hotog'r:,lphs in his l)osSession.
Almost at tlihe commeniiucemeniit of thlie investigation, I)r. William
Royal Stokes, If the Mary land state board I of healthli, informed the
writer that a similar but less extensive e)ideenic had shortly before
)bei united in BaIltimiore. This hlie kindlyv described as follows:
'I'lle inat(tr Was brought tfo lily alt ('lItliilon by several persons, who came to the head
of thelt' d(lep;rn111(,11 and (1complaiild o(f tIllhe skin eruption described. They stated
tlht a 11111111r o1 f people in i sullburban holitl were similarly im. i 1i .I but I do not
remellmbor the IIIlllber. at tilis laie dale. These lpersons volunteereId the information
that tllcy had all been sleeping on somie new straw naittresses, and that all (of the
persons similarly affected hatd used (I1>e imatiresses.
SC('ir'. l ilS






I qaw Doctor (iilchrist, the clinical pr(44cstwr of dermalolo-ny al Jhlin1 11 ; I ii-i
'niv>riity, yesterday le, and het -\ 4 ne II (te O following d.-r rpii ill of tlh e i' Cica-e
Whichili aal eltIJat ll. e hiea-lh deparl int. I tw wii li tlietr iail-c- whiie cori-ipo rded
wilh these. i in o lmrilrrl wi-.
''lThl e'lptoi2 in kenii) i ttcd ilf il lot l,000 whiel', o rvllicmai-t) il hii d e r-, or
tpapulo-withiit 'l hIr-i'ii. As in tki dt 'ripti ii n the reprint ,it I xotor x iotlhTe r
and ScarelIe' )I i' 1'llitt',d SiIr s I't Sahi I(' A d l d Mari .-illI>o,,[i;il litr ii ,,
thev varied in .iy 1 ir ll a itci il .'d it aila d a n'. dl i tti iiit, < r I ia t t*illar
ill hap(t hNo \ -1(ihs 1 er in pi r i w erW Thii (,ruple iiito \i on h ih ic'k cl(it,
aldI iimn iand ea 1k, and al-o on i ri ;le dI h114 I t allowed evidi'iec. ,,f *!ralc'lill ."

BesIides tliis, thcre were several cises reported] to tlhe writer from
northern Mai' Vantil. where fitia ers ini runnii ii lheir \\t e; tl itiiiit i li
f1i11iiiii1r i ill had baleen 1ini hn111 e: w uilyv (ro bll h ] 1) v a very sillllkr or
identic l eI rulive d is.e;i of tie I kin. In a io it wr inat-ance, I I rt I lI ier-
mInta ( iL.i_'h. di. t in l feedl.i e tie 1 llirtislie(i -raill into tlihe cllinder ofl























[titi//"
Fl'';.'J.-AtdIllt jtiilwonn /lJiisiinltrtct), MIhit'll vilifrgo (F'rm llom r .)

t he tIhrashing ina:chliiH was isIo I:Iaffec lc(iI Ibv a d isese (,f Iftl h kin, en-
tirely n nI'III ilir I) to villendinv p]l isivian, I li co,)uhld It Io II siI'v
it with allYy urthicroiId deriratitis known to him. After ilhe wriltr's
experience of previous ,' x-lar, it seemed inpos-isdhlc thit illtils l'dWlhu-
lih, Slhouhld become sufticientlY ailuthilid t to cause11 tlii- ,hrluiialilis
without tire beinl :i1 (a X(*( e siv, e i\ il l)ilna ce sod'f mllle 1I14-1 iillsect or
insects 1111'ectiii-, either the straw or the _-i ii ll'. N l uIrIIitlv thI e
studies 1iiide 1)v hiim in 1SS2 led hili to sulispectl 111: i .1he .. Ill"nois
,'l'.ii~i li tilll (,'ilo ,,It*41 .1 cr,, ,ll}) Iini hit lbe res[ -)o sil)li> for theie i ance of the illites. Till 11. too, lhe fa'nct that It nt l a tacked llie ll ial-
straw worm (,Isoso, if r(lr t lo, inihlieal si] it %l ed hl, iml o s>Uspbect

thiat, Its this particular. specievi is not known to orccir linth1e0 v*icity
of Philihadelphpiia, while it, lieair relative, tile jminl \\worill "I '...>. -t
rit'ici Fitch) 0(1iZ. 9), does occur 1more o less abnatltlllhulilY over the
[Cir. llsj







eastern part of thlie country, this latter species, too, might perhaps be
involved.
With a view to finding out something of the abundance of the grain
miothi in New Jersey, from which State was obtained( most but not
all of the straw entering into the mattresses mentioned by Doctors
Goldl,,,rg.r and Selamli r., the writer applied to Dr. John B. Smith,
state entomologist, for information. In reply Doctor Smith was
kind elii.,ghl to send the writer an advance copy of the report of his
dlelprtmenlt of thile New Jersey Agricultural Experiment Station for
the year 190S, and from this pliublication it was learned that dring
thle summer of that year, owing to favorable weather conditions, this
moth develol)ed rapidly in thle fiehl and there was great damage to
wheat among those farmers who delayed thra'-liiig until September
or later. Furthermiore, a very large percentt;,. of the wheat crop
gathered( that year became useless for milling purposes, and so general
was the infestation that grain from some localities was entirely
barred at mills except when ground for the owner. Some further
investigations (carriedI on in eastern Pennsylvania revealed a very
similar condition of affairs. It was thle straw of I'. i, coming mostly
from New Jersey, hu)t a sinmall part of it from Indiana, that entered
into thie mattresses, from the use of which came the epidemic in and
about Philadelphiia.
In or(her to settle these points, Mr. V. L. Wildermuth, of the Bureau
of Enitomology, was instructed to examine the straw in the mattress
placed at tlie writer's disposal by D)octor CGold].rgir. After a dlay
and a half of careful search, only five straws affected by thle joint-
worm were fomun(1. This seemed( to entirely eliminate this species
from consideration in connection with this particular epidemic.
There were, however, many wheat heads remaining attached to the
straw, an, these heads contained( a great maIny kernels, the contents
of whincl ha(I been eaten out I) tlhe larvie of the grain in motih. More-
over, tIliese eaten kernels cont(aine(I gf i; i numl)ers of thle dead bodies
of Pediculoid(es. That tlhe Angoum ois grainll moth was tlhe cause of
()of III alult nolh from tlhese eat en kernels on November 15. The
larvae of thiis motli inlfested tlie kernels of w heat before the latter were
thrashed(. Man v of these iinfesteI kernels remaining in tlie straw
were included inll thle material going into thie manufacture of these
mat t resses. Thie greater portion of the li in-- larva' of the moth
would develop) to adults (iii il_" May or early Junie, thus cutting off
lie food suIpplt of tliese mites. The mites would therefore very
namtraillv swarm amo(ig the straw and, making their way through
thle cloth ,covering of hliese mattresses, attack anything that gave
proinise of furnishing food(1 and p)reservinig them from starvation. It
seellis that starvation is the final outcome, however, for, as already
Clr. 11S]




15

stated, nI) trouble is (xpelri'nc( ilC usiid tH) wn'mat ees1 after a cer-
tiiin )('crio(I, which pe)'riodl p Ioal)lt t 111 i1 4'- i i Ill(' t( TIlll i )l 4411 f 1t1i'
life of the liit'es iinfe-s1in llt e straw. It thliec foe (I' ld 1140 seem n-. I 1 c-
essI rv to seek furtiiher for 1 It(, pr'imaryi'\ (cau.s [I f t( ( ist-. e(a- '1ie el]p)idlemi.c
of derilaiititi, the (,(ni ter ,of which seclims 1,o h ve hI), ll H i d :il a:tokumt,
Phil c delI phia.
A VES-tTI':1N (I)1IF:MH' <)V TIll 1I > 1M ITITI'S.

W hilo (lhe p)nrodldeII of I he epidemic i1 hle (as(( \v; 1 ; I 1,was 1itppareIn lv
solved soile (,f t he \\(w:ie t sItraw iN vol) v, d ,,d t Iherein h)d( I c(me [from
Indian:la, and duringtL" ( 1' a- fe- w \e:1a> al ot (l,4e11 ltxb l ,)r 1 joiit \ o41rnli
(fig"s. 10 mid 11) Iad been '.,lih rianl fo, e'( liu.li(iil ()lii), lidialla,
and sutihlern Iilllinmi, _____

Iier 'Of I l)OS v (ei'v Seri-




Otils t : I w ll oe'. i' ia lii-
r ed. In ,I e -, t i i al l a't
()if l e thle ia o(sa (do t





pr(evi( sodus vte o tI'es h4d lI e ii 1 \' o
shown that ,II( wltd-
1)lre zI)k 111141 1 e1..-.'i











in the. In (41 isvtand e 41 o ha sa a hp o
p),rti())is )f' Vilgi'i)Hl,






















Pihtsbi, iz, Pa., a111nd six men- 112.12'd iiil1adiiii i wen' attacked
d h Vall'ev. i I ,J
Virginia, :ill(] ill ('ns(-
ern 0 11hi), :Is 'I)-,, s
1904, afit-No,",,,'d)s ad-
v~llicili- bl-ridilv to
the' we, \\,I( wro, .

o:q ()f I )()I t h( I( I- 1
ca)u ~ r I lit,,n til ](I I) I')l))a n t) () co: ,)I I ) ) ) ( ( , , n lit IIIIIII l) : :,:I'a I l a >1 ) I I), ) I.l,)I I ,Id
fo r so)n, I e tii I III barI- I", an~ I I f,,I II l ,,,loii, )) Ii I leI.I)to I
clIf I Ilt to) sectI ( I, olr I I Y Il, l r:) l Ii' s l /l-,I I tI r I' .. i' I it I ( o Ii I s- A I-, l eI,
SlI, I I( 10 l1s( ) Ilr \ ,h,r Ia (' ')I v- II to ( -' I I)v { I() ( I 1 () i,(o( I I -I I'%; ]:oI,\ 'I)
t he pl Ilrl )( )sv, Of f"111,,- w)(,I( I ick,; 4)i or : .1"; l III)st it 1 f0 0 ,i' 1f( ,I ifi~ ) i~( 1 '
cairpet's, an d~ ill 01ii0 (':1'<(1 berriT p c tl~ ,;( - lzidi heen,) :i0 taci(l,;le whe -li(i 'l
straw had( bee(n used( a, ai, inulch floo herli\ v~all< Thi-; cl'iV(;1il(0
fromli ai field tlint ]laid bee'(li so, 1, 1)u l ,I I. V .I 1l'r,)l II ,) iiV)1111 W4W1 i/ 'ck
ill Pl'i ,. In Onle inistaili(,( al (,al](ZI4( (,I* od ivat ,t~-all' \ ;, \\ ,< llppcld'< to
P~ittsburTo, Pai., andl( six ln(C'n tl..,,, l ii { tir, 1 1;s]







by so, llie slkin A eruption, and the horses used in hauling this straw after
it wxas unmloaded also suffered from what was seemingly the same
disorder. Perhaps tlie following from a correspondent of the Bureau
of EntomiLology, reside ling in southern Ohio, will give a fair idea of the
situation on many farmns in that section of the country:
Abi,, t four years auo a parasite was found when thrashing wheat out of barns. It
seemed t o a effect tlIe victi 1s alinmost as soon as they got into the mow. The men began lo
scratch themselves, generally on the
S\ ne(k and on the arms (inside) opposite
'\ \ the elbow, and on the bodv. back and
front. TIli. lparasites raised welts such
\ .1 as \yoi describe and sl)read as you in-
I N dicate. They have spread to such an
x. \extent that farmn hands dread them
and will not change work with neigh-
.^ .- bors unless they thrash in the field.
It / ,\ Ier(, of late they are found in wheat
S' straw in the barns, especially if bIaled.
/ Last w(,ek a farmer brought ime baled
S/ whiealt, straw thzit seemed to be alive
\\ wilh them. They attacked every one
*. 7/ that went intolhe barn, and one of my
i '///*' horses t hat wvas I" r 'iri i.- from effects
of a drive was simply covered with
// / little knots or swollen places and bit
and rubbed himself continually. I
,t thad to have i(, he straw hauled out and
/ bburnedand thebarn disinfected. Tihe
S'farmner stated tlhat they were so thick in
/ the shed that contained the straw that
i /// he ad to.keep all stock out of the shed.
Malny other similar letters
from towns in Ohio wNere re-
S/ (eivd l)\ Doctor Schaml)erg,
// )arti(ct.ulrly from Zanesville,
/ (oluml)ibus, Vincent, SpringfiMeld,
( etc., where I lie affect ion is
.- ( ..... )popililarly believed to) l)e due to
F|,. 11. -l-Fl te Itsomt im i act (if delposiling egg ill ('lhggl'S. A physicians from
stt,,. bAhm, lifet iz. (ti Ihot silliustratioi.) tIe last-na ed l town stal t ed tI at
ill thlie fall of 1900S during harvesl and tliri-liil:i lime lihe saw in Wash-
iigtoii ('ouiintYV soiiie S7 cases of tlihe disease in (lquestionl. It affected
tlie harvested's am1( thrashers. This sp) iil lie(, ob)se(rv'(,d :;' cases from
(cotact'l withi stlraw licks refilled witll straw of last fall's ('crop. Tie
d isevase is said to have been miore prevalent last vear (1 90S) than ever
before. I1nformliaolt hlis comlle from ( Columb)us, (O)hio, that )potters
\lit use, I st raw for 1:1o 1i. ll- crockery ware have l)been so badly attacked
at limies (lint Ivli entire force of pal)ckers has b)een off dutly. Mlany
I 'ir, l SI






thnis ai hile c iarliod of straw has been ,so adlecltd Hiat tin( Rise of
it lhI>s b-een abandoned. In Sprilngfield, ()hii, it is sid tllhat the dii-
easw was so lhad a X\'>r seriously' to hatlper tle Il t (' t .pro' c fi tle louli ct -ttcl i i 1 a l(' R e. sever;
tlOi i'. ,wever, ,,,m_lit haHL ve len Mir to attack, I, other miles,. In
Zam-isvill,, ()OlW li I |ttes have beIe NOi,_. to abanldon Ihf" "se
of sthnl',a u l tqin loly | airie hay" fo' r .. L i, |)ri[)(ss.
)DoItt-r S:,laiinbg was alli ilinforltil ly a plyi-iain "if 'it sbu;r
that a X .iii-" wt+oi man pmati tj l hail ."foetVr nd inr tl i aln ;l] tilln v.It.l\
rl-e, iili .i_ if hot iili'ttihal w ill tlh one until der mll ill"ili litionll each
tihm that she hb&l assisted in iuldy-ingi ea-s of Kite.,-, packed in
straw. lBiothli th(e physiciiall anil tlie pal tient hlail tmlu' t belie e thllat,
sometl.ii._ in thle straw wl as tilIe ali-'e of tie etlruptitil.
Ind1ei'd, s nIearly dil the territr'y frimt wl ih thle-, co pltl ilaillnt
came to us 'oincidle ,ith tlhat all'etcd 1I" tlw jinit orm that it
created the -lt pivioi i ti ,,ill ily anion lleiiS t nll A' t in ille iii vsltiga-
tiolms, hbul even llliig fitrivvle lel(le -sel\ -e, ilial t liere n11111 lte soli(le
con eli'tiiol litqmx yenll I le ( i p e oliilmnena. \V Illleiii Rf llie--, edaI>se
,l'were hroult il tlo li e titIe oi p tiii living physit ian-., Ilut lile lali ,l'
were ait a loss to attiiccount 1l ti'e prevalence oli tii dl erl-atii-., i ll al v
iof thmilli slhppohl in ii to he b iile ra'scies o' i ta- h ill i ( a- wa liil' i 1i Irl
'conltagiosl tlie 'Xai naltire4o whici h tit l'liX diid not kntlt, The lia-
hbitvii o' ci nfuiion with othl r Xvasl- o llsii eriiiiitio o lntallio I disteases..,
Ilotaldy s atllpox, was of cr'line very '.., i.
Ailloill tlhese ls li\"si- ians ma-. l)r. I\ illaln T. lawIvles, ti' llunli r-
townXXi, Int., wXlio, in May, IS'Oli, U ert lmlook a earetfli .s lil vt i 4 a illiniu e'r
(Il ra is ol this denllialtitis that hla ctll ulnl iltier iis pvrsi lal diiservXa-
tioi, as ell it-- (ti-e l i sot e oi l i l t as-a- iate-s. 4)oetoir i Xa a It- Hawkss invXe-
li.- iti its w el'e very careitf ully i iad', and tle res.lill. alre ex eedt ll;.in ly
valiabtle for 1tie ieaso, thatI in the case-, ( tis \ stern epidehnic, hle
\vlh~ii ele Iti, t I t'i+ttl lllt l' f'-' l ii +.q tt 11111ti ttll l ei i e, lieY<,
was able to (araceieti' cause ol' the skin pt1 i io ti lie Wile (/'/ 1 I44 -
b<+i-bs 'i itr fpji-iuis) andlil follow tins., back ti tle lhost insllect, the Xwheat
joilntworm XIsD11 II tiI i-i It 'leaRrs I thi e oi s curity Il iX iTou-m.ii.
the cause of t(ns i viihniic in tihe Middle \\W e>t, aI sevc ti til+tlhnuti
which tie Aliiion ois prail niol Iln\eX r oct llr ill exce ive, aliiii allim'
ex epli'ii,-" in ._1.,ii tlat is k pte l in s 1tre, irnli tli toI il\ in ll liie ore
southlerln poi olln iii Ililiali aln; IllinoiH .
In Myay, 19Mi), Dotor iawlhs fotuId in his practice dial .a very
striking ly X -l.li .._ sk. in disease.tii p ieenie' it elI f in I i- iX, ahni ti lie

in (v) ini, 1,i I A ntsitii i n 10 o t iii- il: i ii ilit, for A "i ni I iWi ii i-+ ,i Ii IA ,Ii
inve.-tii;;l iint.+ i~s t'<>fm-['itihl, I >i+liir .I n l+'+ !< ltii t++~++l lntt+. fi'eiv ;i++ )it' it-rirl'iiiiilt~
0( lh 1 liilr inthe h l \K% i| in hiis a m n-i ... i al' ..li r l il i. r+ i t I l r, i '_ l d,. -ii+n "Ii-
iulir' in Ili- iIt r, |- rint1+i | in 1ln> .l-,r 1- i ln l > n,! i 1 ;> I M I i i l i 1,,
A IIll I,-I> ltt, 1 1 iull l tW .rt r ,r-r]t l -ll.( tin ti. < n /i s s
for D#itrojiiiiiihis ini+rio.t iriffi+ wht'lrt-vcr tltie latter nai.tiit+ I)C(n-tir- !*'. M + \V.
It'it. Il l~







surrounding country in epidemic form. Through tlhe press notes it
seemed to be quite general over the northern part of tile United
States, limiting itself to the wheat-growing sections.
The people generally affected were farmers and those living in
small villages or towns where straw is used int beds, under carpets, and
around stables to bed stock. Horses and cattle have been seen with
ai skin disease almost identical with that seen in man. The followingi(
incident led himi to anll investigation as to tile prob)alle etiologyv
A family had cleaned house, refilled the straw ticks of their beds,
and placed fresh straw under tile carpl)ets, and in about one week the
family had developed this peculiar skin disease. In thlie beds was
found a small black fly (I.sosom/, tritici' Fitch) about tlie size of an
ordinary gnat, which at first it appeared to be, but closer obl)servation
revealed that it was not, of the gnat family. It'pon examination of the
straw it was foundI that a large number )f tlhe straws were perforated;
these lperforations were through the wall in tlie region of the joint,
generally about 2 inches from the joint. The perforations were about
tile size of a small pinliole and ranging in numiiber 'from ten to thirty in
a straw. Upon examining a section of this straw thlie small black fly
was found(l under lmal\- of lhe openings through tile walls.
Several flies were examined to ascertain if they I) possessedI a piercing
proboscis, and while ob)serving one which liad jhst 1een taken from
under tlie sheath of thle straw, through which there was no perf(oration
over the fly, a small mite was obtserveId crawling over tlhe dead body
of the fly.
Placing thlie )bodies of several of these flies under the microscope and
u-i g, a one-f'(ourth-inch objective and a No. 5 e vepiece, it was found
that oni nearly all Hlies over which tlie wall was intact a small mite
('culd 1be detected, these varying in number from two to four mites to
each fly. Upon furtilering thle observations it was found that the
dermatitis lasted after thlie (lies liad been oblservedl an11(i extermiiated.
Thle following experiments were tried to) prove whether it vwas the
fly or thlie mite that was thlie etiologic fact 'or inl producing thle dernimatitis.
Six live flies were taken, upon which no mites could be found;
these were pIlaced under a watch glass and bound upon the right arm,
leaving them in contact wiith the skin for' three hour(m's. I pon llie left
arrm four deal flies, oin which liviiig. mites lihad bIeen ob)serived, were
placed I under a watch glass and left in ('contact with tlie skin for three
lihours, after which tlie glasses were removed and results awaited.
TIie riIdit arm showed nothing. I)pon thle left arm there appeared
wmithill twelve hours four small wlieals, thle character ani evolution of
which are later described.
To) further tlie experiments some frieshli lesions of patients were
scrapedI and tlie scrapings examined miicroscol)ically, and two of the
miles were found in the scrapings.
I Cir. I lSJ






Itching is the most prevalent aIIId first symptom to attract tiI(
attention of tIhe pantietOt. It is molst per.-ist en( a ndI intePnse durintr ,
the after i|art ofI tie ni.liit. At al outt th i ie ille t ec' h i tc'li ost
intense tlwre alppeati an urtiearitiil erupti ion, accott ilpanild, in se' t're
casms, vmith general sytemic syn|)tomis, suclc as rise of temperature
fromn 119 to 102!; in oe rumli the tvmplerattrei rose t" MI0S: the pulse
rate is a ccehleraItel Ito I 0it, o) a A iiras I1I ir I s I I -- in1 o1e a' t- Ise to I30 .
otherr sy' ptotiiis etre intense hea larlie, ainorexia, nauseit'a, in stolle
case-, voillitin, and a mnild Knit (f diarrhea. In savee cases Print
complained of mineral joiot patins adlit ackul he'" in t ltWe cases thie 1i'ilni
was exaiineild liind albunin inll t mii ni unat t'as oiund, iut no cas ti or
lWIod. When tie acutte syilliiptolls disaitppeared, sii did >ti he albumin.
Manit y p atiilatls who1 ( /lt'ert l from mill as l omll a lii neit d (di nothing
asible froin tiet intensely. itching. If' nll stral iw was rediinoe i'ri n tliite
beds land luse, lu illt e symptoms l siubiiid in oett or t(wo tdays andl
completely disappear in a few da\ys+ More.
Tlie lesion, whilh is typitial d thl disease, is t ile- llie ll u ti vesil'cUloa.
The lirt icarial vision variety s in size from thliat a split l' a to iith t of a
penny it is surtroni d dit-l y a pinkish lilo, ivaryingti i i intensit. otf
Color f'roti a pale pink tot a most beeright pink.l' The "thivet"-like
Itl.sion is at first tblahl 'rd, but later I )eolil s a rn itose-eld co,1 It is
elevated about I or ".2 illiimeters above ilel stkiln l'lt'a ce,. anid is solt'-
lmounted by a sliiill vesiclhe contaitiiingl ai whiilis fluid ariia ting tiet
place of inoculation. Tlhe vehicle is a otim 1 or 2 liilli etersi in diam e-
ter anl ehevaled about 3 millimeters above tlie surface of' tlie urti-
curial lesion. As tlo lesion, grows old it throughh i llie press of
evolution: (1) It is lIancheldv and hias a cenitral vesicle: (2) it is rose-
red and thn' vehicle h yV Ibecomle a pistule: (3) it p, i,,i..lo receodes to
tle skit level withi sp alt formatlion, due lt, t i lite 'cratclhillg; (1) it leaves
ta brownish or reelnisli-yellow or purple sp it ilon skin ,ulfuce. In
d(bilitated patients thie markings loo, not unlike Aided indvllhd-
pencil tarks. (Tahis was oted in n Ipti nt suffering front pulmonary
tuberculosis.) These discohorations ii n v last for several weeks, -
TVe anatiomical loWation of "lll lesions i's Zeneutrallv tlhe buck, sides,
and abdomllen, and le',s frequently llie arms and Thlh. Tlleneck hias
very few lesions; thle STae, lands,. and feel have ver- vew or tnoe.
'lie' nber o4 l"esos depedns uIpo tlhe number o|" inite, ranilillg
frontil verv few to Illousunds: in somle cases tlhe ack and aidomlen
have been allm+ost a solid mass of lh ions,, new\ leh,-i s f tile t s), of
old hlsions, so havi r_' lesions in all s+ i.,-- od devel, pniei il.
Later investi-ations carried ""I bv- NO. Wilheriiuth, at Lafayitte,
Ind., during. December, lU1909, and ,aintialrV Allot February, Il9i, show
that where straw is keIasls inll masse. Zi i stacks anid barns, til llieites
literalltv swarm tliihi,,,'.-li e strum, and as soon.,< t as all I i or its
parasites attempt to glnaw their \vai out through the(' cells in the
0 t'ir+ 11s







straw, the mites enter and kill then before they are able to enlarge
the opleninig sutlicientlv to enialble them to make their escape; indeed,
nlot loe tIhan 5 per cent succeeded in escaping.
A.s t his represents fairly well the conditions of st raw in spring and early
SUmmlner when it is used for the manufacture of mattresses and on the
farms for thle filling of straw ticks andl as a substitute for felting under
carpets,the r; I number of cases of this dermatitis occurring over the
country is not at all surprising, and the indications for tlie season
of 1910 are more favorable for an increase than a decrease in the trouble.
OBSCURITY SURROUNDING THlE OCCURRENCE OF THIS SKIN DISEASE.
The exact nature of this eruptive disease was not at all understood
by the medical profession throughout the country. In southwestern
Virginia tlhirashermen suffered from thlie same disorder, but attributed
it to chiggerss" (1ig. 12), and l cal physicians, though skeptical, were
thleminselves unable to correctly diagnose or to account for the trou-
ble. As the disease is not serious and passes away in tlie course
of time without leaving
i the patient in any way
\"f permanently injured,
it seems to have been
> '-' palissed over by niedical
-- i men without i'\'.-lia-
tion. excepting by tlie
L '' l)physicians whose publi-
i A cations have just been
> --T cited. Alonglo the peo-
pie themselves tlihe erup)-
l'' 12. / i ptrisa riin'ia t, 'tl ; 441t; sirrilc rih. ii;hl t ion w as p)rol)iblv m ore
i .. -...i.. ,..l (A fth r lK ihcy.) < ,1 t ,
frequently attributed to
att sacks tof" chi'..'.r1" or a "rash than to any other cause, and it is quite
likely that this common erroneous interpretation of tlie origin of the
erutipt ion has prevailed generally throughout thlie country, inclildig tlie
Upper Sheimandoaili Valley in Virginia, where thlie joint worn was abun-
damt as far back as 190)1. It was, coniiseqiuently, rat her unfortunate
that, wvilli tlie beginning of this disorder, an institution in oine of tile
States involved shotild publish a newspaper bulletin crediting the cpi-
delmics ,of this erutit iou to thle attack of 'chliggers, anmd, furthermore,
that a s secondd press bult let il, .r,"'ii,1 ,:,l ii tlie first, should have been
issued and sent to every nIewspaper in t lhe State and f romn these copied
into other iiewspapl)ers throughout lie contrv. This it was that an
elt irelv errolnelous illmipression was nlmagnilied and still further dilffused.
In Order to1 determine thlie likelihood tl hat thIose handling straw in
the wlheat field will be attacked by the small red mites often mistaken
for "cchiggers" that albound in thlie harvested grain at this time,
[cir. 1S]






M r. W ihlernu lh, id tI& l B e lor+ l':t,, l.e hel, a ei t XllH ol X lll)(," (i)f
experiments. Ii no) (viae was lhe abie to po oke to ;i n attak ]'rn
these r(' i'i ites, lroal' lhy 7uix l, i even whesni. t\0 e1 ll ,v i ,,r, co)inliiedi
upon lthle skil l If lis bi aril 0 1 the other lhand, ll xail ie ations of
straw froi n vaio -s i ntI e.s in ()lio it in lilianai haive r"ve, I illed
rsei n'" of PIed clloi desulih il thle (eIl o liie'l l lv t iW ,lie JoAintw(rin.
Tlil i se ins to entire eliy eliiniai "i ihi ,rs" froin these in\estligeations
because thes'e were pwro ably not pr''sent aind tlhere doe) nl, l o(,l er
apl) ar t(o l)e an dhult l hat l'hi xili tif,. i 'r, l tr ,,:il.x is t,, hae ch ri'iI,
vith calslii l ng l i'e pidem'nic of tlis i erah i tiili. iThe all sli 4 iits ( nli
lex ess iv i a1is in t lie i o!lireal sI i of the Aiitiii (loi-, r'aii
lilth ilpo theil rlin in the I alst an lie jt i int i iwori inI lle \\ lie i l wi rina
in tihe middle \\ ist. Thereli fore e i ligiiei ... l" It-l :do a ,r i(o figl te asi
t illt i it suchii epidemi'lcs. i
lI ll'rI TI IIO)W N I)()N ()THl I';I; r ;)I I ,.'-MS
lhi'se iinvvstigial l io s have illis!tatel very & Mlyh. I I lihe extent to
which tli e sollh itioiin of loni en ii( li' 1l pilrTo h \'liie will at t ie a:il'
tinell im) sove othi er probdem"s more1n OF less (loselv allied I() tilt, ori)g_-
hia i iin rlhl ligit thl rn)il ipol )i hlihe owass os f a erpi'l i iio i o te by
)Do'or Hairris i in coiln iie i tio e w ith lit bailey ih\ il i joit o liai ailr
e)en xpi aineld. Thie Ial t's(il ot -reak ofl' tIx he joilltwori in ilhe (Ohi
Va llhu proailyl oxrighmole in ( Ulep'r Shh-inan(h)ah Valle yoh ,f Viti-
pinia, exteldini nortl wald and westward 1 hroulioi wi_ t Vilr7riliia
lii n e s.lsrn Olinx lieu invest l i'al lio iil o ill, isect \lis taken ii i in
1!9)-1 a parasilte, ]0/1ronip;ml o iin #i'< ,t ';/t7 ('rli" ofksr([, \\ N also i ol ed ill
e'x e'ss';ive' alxin izi !but to so e reason, i( diiilnot ovel'come li lte ji l-
W\o) 1t. This hi )ll)iiin)In hl as l- een noted ( tillitiiiallV. Smi e tlhat
itie it lius e n a pi epli-et a n l t'i a tho t e rie r lx l,,il ,, i a t l \\ it *t A li
Rich anli n "rli ~laie ol its natural e eli eiit, lli joint on ii slls ildl cion-
tillue to spreadd and increase in -i rtin ivenes-<. N ,ow, howev,,r, that
w know that t his pl acit s i tie ihs d a ) (lo'l d 'v loptliiin i n -.i, *lie, l,(
(v1ar's in sut'i ee illitll,.t, fill Inher's n connetli o i with ll .oi, ,w ii, t1ie"
Latter comes nearer a s il (l ion. 1 )ht ro| i )inotus.a, w, ell a-s somIlle o)tll(er
parast it e v i e ne ies of t Ilw johill "t w orn, Vemerge( in Ilrv jIi I l\' 1 ,rom t)iat
were previ)oiti~l\ |lacd( l in tl(e cells oc upied I ilieo ](ill l,\() o'li. Ts
s1oiI as tih e od t ll |it)ar tsit'-s .ierge they al oe )Vi|)osil i lls c -
tainingl jointworll larvae of ( he sai. e z. wi ,ltI li ]i MtieA n
the snieilv devehlope Thelie i ] nct"W ,fril o|tf e cells 1)\ tlhe ovi-
positor o, tlihese parasites, particuihirlv I it rwin tji- n,!opens \;i tv fo)t
thle entrance of this lic w(l)- i(c niile. und, ()o1ce im>id olt' (4 lie cell,
it will (destro *vy ,veryt iing, tlierili, \ cililer it le jhie t w)loll (o pa a-
site. Thus the predhwins ite litv as p)even ted thle iolir lp raite,-s
froi emit rll' )l i, e | ()It'i r / woim 4 ec se it lias (cIiil"iilv Vcht c ed
tihe increase of other parasiies.
I c(ir. 118]







In the light of the foregoing, it would appear that the only way
to evade the disorder among human beings caused by this mite lies
in preventinlig the occurrence of these two destructive grain insects
widch alre respollsible for tlie albunmlaice of thlie mite itself. There is,
therefore, a double incentive for the farmer to use every effort to
prevent the occurrence of these pests in his fields. In many fields
inII Ohio Mr. Wildeinitmulh found that more than one-half of the straws
had been attacked by jointworms, and the damage resulting from their
at tacks amiiounte(I to a considleralb)le percentage of thlie farmers' wheat
crop. (See fig. 13.) In addition to this- and we now know that this


;*-.' .7.*



: 1
- "


-I

a


F I;. :t. ieIiti.lion in yield of \vlw atat a act'ked by joint-
wo m III I( s1 \ i I I a Ii lii li n lltt i Ii t il 11 tol a illI s yield
from 100) i w1CI i tom u inifrtid sIlaws; lu1i ol, righi
)onlintis Yichl fIlomll 100l hl sad Ioulln illfcrtled .stra;w".
(Ori'iinal.)

produces vymi(. This doelplds 111o)1


mite is generally present-his
own family and employees
suffer the annoyance of this
(lermnatitis and also those who
attempl)t to use mattresses into
whlichli the in tested straw hlias en-
teret1. Thus people hundreds
of miles away, unaware of the
presence of these mites in mat-
tresses, aire caused not only
great .,'_-_i ovationn but intense
suffering through their use.

I)EVEIA)LOPMENT OF THiE -MITES.
Thle investigations carried
out during the winter of 1909-
1910 by Mr. Wihhermuth reveal
the fact that a period of from
six to an indefinite number of
days elapses between the time
a female emerges from the ab-
d)men of the mother until it
I(,l1)periat Iire.


For a temperatures o4 friom 90 (() 100 F., six days elal)ses; for a
tempera t ure of fro SO() to) 90 F., seven d(ays elapses; for a tempnIerat uire
of from 70 t) SO0 F., iinle (lays elapses; for a teml)peratuilre of from
(()o0 to 70 F., thirteen days elapses, am(I for a temIpel)raitur'e of fronil
50 to ((0 F., tweniity-eighlit (lays (elapses.
With Iiltempe'ratulres lower than 50 V. it is doubtful if the mites
wuhld develop. The periods required folr thlie development of differ-
ent females sub)jecte(I to (ti he sami telpenl)raltiure are very uniform.
(For instance, illn tIemperatures of from 70 to 80 F. nearly every
female pIroduce(Id Young in (xaclly nine dayss) The life of th mites
[C'lr. I S






varied fromn eighteen to an indehlinite tumh1"ber of dayls f,1rtv-lllree
davs m as the iaxinuini .i,.l for those kept under ti lt'he L' tepe'llll'a-
turesI The numlel l of Ian produced 1 ai single 1 fm lale vaia led
conside'rably anel v riitioe wias geatvi'r 41 L '4 individu ld!s ulpller
li 'e conditions than 1i 4 no those uld'er conridti( la l itions. The
number varied froin jutst ;' few to 270. lFro :1 to S naudhs were
usually tro umIend, there eiin two xceltniInls tlo tis: In ne instance,
when the teperatureinini was Ietweem 70' aml SO'l K"., AIL L)11des were
produce ti n l iun another case a la'. iiinunt er. 'The' lirsthorll in lmit'
cases fwere males. The largest nuilmhber of Youtil' produced during'
any one dav Iqy single feale \ as 52.
Tho idhal te pnleratlre for raptiIl deve 'lop en'.t an 1l l )v prodIl1 'tion
of the maximum nI e o4ll)' l' yi)n was i'i4 oi4 1 70 l o' sL it4 0 1 S' K V e ab-
domien of tle female reaches its mnaximinnm siz.v in aout live dayvs.
Tlhe ile is omnivorous, toreet ringF smooth l]arvi to lha vir one,,s. A
yo i g mie can nott ea enter n 'iles Isoisnt a M4'll. Miles 'an live onlIv
l short l ime without Ot'I d l' ss than aI lav in all ess observed.
Copulation occupies (Qlv a few minutes, (lt miales rarely *v leaving tile
surface of the abdomen of their loter. In tlhe lalboratory ax single
Isosoma puipa or larva will sustain a fe'mlale up1t to the imue slhe pro-
duc('es youin a-. c llotilel 1 to suplpo),rt her prog)en tv'' for4 In t\Ivmen
to twenty-ei i, t days. II thle field, oIl under naturaIIl condi.i IoIs,
o11m pupat wouhl h probalty furnish food.1 for live lit'l s for approxi-
mnatel tlhe samev length of tim. as in one experhimet a puipa furnished
sullliient t'1food for a monthly The mites ctI LI kept1 alive, tx sI l>" | .IC-
iilg them to aI low ttempwrature and development cheeke For all
indetinite time. Wl'hen attacllki-ng human bIings they dtio not, bury
themselves in thlie skin and remain there as ,(l tie cl1i4ers."
11'rE.TIVK AM) 1KOT1CTIV .
Throughout the territory involved in 1l1, easterl epid mic old this
dernmatitis, wlint was due to tle excessive abulndancye ol4 tllw A.nou-
rnoi.. grain moth, the eviW he e recently vob trained h llvte riter Ias.
been ovevwihelinindly to the eo'eet tihat lwere wheat was thr:ashecd
as promptlly as ipssidle after harvest ami dIirec'll Mrono l.. Aw.hoks
W (lhe fild, almost no) occurrence od' thInsy"ranin~h "Abov.\\i ol which
there would he no mites, was olbserv"e I b ilhlr. ;il tolier-. han-
dIling the thrxashedl irain. On (lie otiloer and. when hauled M'otu
the liehl am! laced unthrastted in tlue barin, I&led aae I'rdo m tnhis
ju(st has variety up to nearly 1i) per cinl, anip !Ios -ii Ail'clct, thle
crop as to cause its rejection1 by mlillers. ex\cepf \whee !Lrroluh on,
the fart mer's order, llere, tlen, is a mean-;s of proillytionl for people
who IIse ()o liamlle whleat straw growni i t in I his x lon ol I lwie couIIl rv.
In hior Inliana, anol Illlinois, where (I= A ,ile ca'i- i*J this der-
mIatitis has increased enlorilously (ot account olf thle prevalence of tho
|Clr. list







jointwor'm, wheat placed in the barn before thrtltin-Ig has been
fouiml inmuch more likely to produce epidemics of this disorder,
altli,,i. lihe difference between wheat thrashed in the field and in
the halni is not so stbi ilking as where the trouble results from ahbundance
of the grain moth.
A careful study of a large number of wheat fields in central Ohio
by the Bureau of iIi' v has shown that the infestation from
the jointworm lIuring the season of 1 909 varied from 1 to 95 per cent.
Here, too, the mite was found generally in the cells in the straw
occupied by the jointwormni larvav. It has been found that in central
)Ohio Septemiber sown wheat is much more seriously affected by the
jointworm than that sown in Octobl)er, and also that the infestation is
worse in )both) cases on poor soil than on that of an average degree of
fertility, and still less on good soil. The infestation is invariably
worse in fields oni which wheat hliad been grown the previous year, and
in fields lying adjacent thereto. Fall-plowed fields showed the least
infestation of all. It appears, thlierefore, that mo(lerately late-sown
wheat on good soil and on land not devoted to wheat thie previous
year nor lying adjacent to such fields, escapes with the least injury,
and that less tdifliculty with the derminatitis is experienced where
wheat has been thrashed from the field and as soon as possible after
the grain was harvested. As the jointworm winters over in the stub-
ble, where this can be burned during fall, winter, or -IpriiiiL', the
destruction of both the pest and the mite in the field will t)e com-
plete. Where this can not l)e done, muchi good may be accomplished
by raking over last year's stubble fields in the spring and burninig
the stubble thus collected. So important are these measures that
'acticing i)hiysicians miight almost include them within their pre-
scriptions for this painful skin disorder.
sUG(GESTI)ON TO) (COHRESI'OND)NTS.
In order tliat this mite imay be further studied with reference to its
direct relation to man, all letquests for in formation and corresl)ond-
ience relating to derinmat logical matter's should be addressed to
ID)r. Joseplh (Goldberger, l)passe(d assistant surgeon, Unitedl Slates
Pul)lic I lealth and(I M;alrine-Ilosplital Ser'vice, I lygienic Ilabo,'atory,
Washington, I). (. All correspondence relali,.-. to entomological
and agricu Iiltural matters connected I with epidemnics of this skin erup-
tion sliould t>e addressed to tihe Bureau of Entomniology, D)epartment
of Agriculture, Wahinilgon, I). C.
Approved.
JAMES WILSON,
Secretary of Agriculture.
W\VASIIIN(TON, 1). C(., January 11, 1910.
('ir. 111S]



















































































































































































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UNIVERSITY OF FLORIDA


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