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UNITED STATES DEPARTMENT OF AGRICULTURE 
FARMERS’ 
BULLETIN 
Bo Ad 
NES 
WasuinaTon, D. C. 671 May 26,1915 
Contribution from the Bureau of Entomology, L. O. Howard, Chief. — 
HARVEST MITES, OR “CHIGGERS.” 
By F. H. CurrrenDen, 
In Charge of Truck Crop and Stored Product Insect Investigations. 
INTRODUCTION. 
Residents of the South and of the more southern portions of many 
of the Central States, and especially visitors to these sections, are often 
subject to great annoyance due to the attacks of mimute creatures 
popularly known as “chiggers” + and ‘‘red bugs,’’ and incorrectly as 
ticks. These creatures occur in black- 
berry bushes, shrubbery, grass, and 
weeds, and persons walking or sitting 
down in such localities are liable to 
attack. ‘‘Chiggers’” usually enter 
the skin near the shoe tops or at 
points below the knees, but some- 
times they are jarred from bushes or 
small trees on to the neck and other 
exposed portions. Their habit of 
burrowing under the skin is not nor- 
mal and brings about their death. 
fi ; Fig. 1.— Trombidium: sp.: Larva, highly 
Nevertheless the inflammation thus magnified. (From Banks.) 
caused may become very painful, and 
where many of the creatures have attacked a person this may fre- 
quently lead to fever or other disagreeable consequences. The desire 
to scratch the affected spots is very strong, and scratching with the 
fingernails may easily abrade the skin and might communicate infec- 
1 The name “chigger”’ or “‘jigger’’ is evidently a corruption of chigoe, the pernicious sand flea (Sarco- 
psylla penetrans L.) of tropical America, a true flea, which crawls under the toe nails of man, producing 
painful sores which may result seriously if neglected. 
Note.—This bulletin, which is a reprint, with revision, of Circular No. 77 of the Bureau of Entomology, 
U.S. Department of Agriculture, treats of the harvest mite and means for the protection and relief of 
human beings subject to its attack, together-with methods of eradication. It will be of interest wherever 
this pest is troublesome. 
90570°—Bull. 671—15 
