
LETTER OF TRANSMITTAL. 
U. S. DEPARTMENT OF AGRICULTURE, 
DIVISION OF ENTOMOLOGY, 
Washington, D. C., July 15, 1898. 
Str: I have the honor to transmit herewith copy for a new edition of Farmers’ 
Bulletin No. 19, revised to date. The bulletin was originally prepared under my 
direction by Mr. C. L. Marlatt, first assistant entomologist. Since the publication 
of the last edition some advance has been made in the subject of insecticides which 
necessitates the publication of some additional matter and some change in the 
methods of preparation of old and standard mixtures. The constant call for infor- 
mation of this character will warrant the publication of a fourth revised edition of 
this bulletin. 
a 

Respectfully, 
L. O. Howarpb, 
Entomologist. 
Hon. JAMES WILSON, 
Secretary of Agriculture. 
CONTENTS. 
Page 
Relation of tood habits) to remedies-s 42+ -- 2-ss)se = ete emia eee ease eee 3 
Insecticides for external biting insects (food poisons)..---...----.------.----- 5 
Insecticides for external sucking insects (contact poisons) .--..--.------------ 10 
ID YRSy an ayes CAMA LS obey py NEMS A555 Goedog bo eco 6S00a0 saooo0 Dae osSo da D> 25a 20 
Remedies for Subterranean 1NSCCUS a. ssc) ase sete te relia ake tein a) alee oa eee 23 
Remedies for insects affecting grain and other stoned products: - 2k aeeseee 26 
General considerations on the control of insects..---..--...------------------ 28 
ILLUSTRATIONS. 
Page. 
Fic. 1. Tenting trees for gas treatment, San Diego, Cal. (author’s illustration). - 17 
2. Method of hoisting sheet tent (after Craw) .-..-.-.---.-------.------- 19 
3. Gasoline power-spraying outfit of the Division of Entomology, U. S. 
Department of Agriculture (author’s illustration) ......-.----.------ 22 
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