LETTER OF TRANSMITTAL. 
U. 8. DEPARTMENT OF AGRICULTURE, 
DIVISION OF ENTOMOLOGY, 
Washington, D. C., July 15, 1897. 
Srr: I have the honor to transmit herewith a third revised edition of Farmer’s 
Bulletin No. 19, a condensed account of the more important insecticides for farm and 
garden use, prepared under my direction by Mr. C. L. Marlatt, first assistant ento- 
mologist. During the three years since the publication of the last edition some 
advance has been made in the subject of insecticides which necessitates the publi- 
cation of some additional matter and some change in the methods of preparation of 
old and standard mixtures. The constant call for information of this character will 
warrant the publication of this bulletin in large edition. 
Respectfully, 
L. O. Howarp, 
Entemologist. 
Hon. JAMES WILSON, 
Secretary of Agriculture. 
CONTENTS. 
Page. 
Relation of tood habits to memedles:=seses= ss eee see eee ae eee 3 
Insecticides for external biting insects (food poisons)..---....--..----..----- 5 
Insecticides for external sucking insects (contact poisons) -----.-..------------ .10 
DUS Sandys Pray UNS yay ace UWS eee 20 
Remediestior subterranean MmSectseeeeaee a eaeee cies eee eee ee eee eee 23 
Remedies for insects affecting grain and other stored products --...---------- 26 
General! considerations on! the combrol ofmisectsess-eeeas sees eee eee 28 
ILLUSTRATIONS. 
Page. 
Fic. 1. Tenting trees for gas treatment, San Diego, Cal. (author’s illustration) -- iy 
2. Method of hoisting sheet tent (after Craw) .-----.--------:-:+.------- 19 
3d. Gasoline power-spraying outfit of the Division of Entomology, U.S. 
Department of Agriculture (author’s illustration) ..........-..-.---- 
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