UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1137 
Joint Contribution from the Bureaus of Plant Industry and 
Entomology, in Cooperation with the Illinois, Indiana, and 
Wisconsin Agricultural Experiment Stations. 
Washington, D. C. 
PROFESSIONAL PAPER. 
March 22, 1923 
SYMPTOMS OF WHEAT ROSETTE COMPARED WITH 
THOSE PRODUCED BY CERTAIN INSECTS. 1 
By Harold H. McKinney, Assistant Pathologist, Office of Cereal Investigations^ 
Bureau of Plant Industry, and Walter H. Larrimer, Scientific Assistant , 
Office of Cereal and Forage Insect Investigations, Bureau of Entomology. 
CONTENTS. 
Page. 
Introduction 1 
Symptoms of wheat rosette 2 
Symptoms produced by the Hessian 
Comparison between the symptoms 
fly 4 
of wheat rosette and those caused 
by the Hessian fly 5 
Symptoms produced by the wheat 
strawworm ._ 6 
Page- 
Comparison between the symptoms 
of wheat rosette and those caused 
by the wheat strawworm (>- 
Symptoms caused by the wheat stem 
maggot T 
Comparison between the symptoms 
of wheat rosette and those caused 
by the wheat stem maggot 
Conclusions 7 
Literature cited S 
INTRODUCTION. 
Shortly after wheat rosette was brought to the attention of plant 
pathologists, certain workers advanced the idea that the disease 
was due to an infestation of the Hessian fly (Phytophaga destructor 
Say) on account of certain characters manifested by the diseased 
plants which resemble those of plants infested with the larvae or 
puparia of this insect. Although this view was not held by entomolo- 
gists who were familiar with the situation, it was considered desirable 
that the latter group of workers should cooperate in the investiga- 
tions in order that the possibilities of an insect cause might not be 
overlooked. 
The writers have made observations and conducted experiments 
with wheat rosette and also with a number of maladies of wheat 
caused by insects which in certain stages of their development might 
be confused with wheat rosette. 
During 1920-21 careful observations were made on wheat plants 
growing in soil infested with the causal agent of wheat rosette. 
Three plats of Harvest Queen (white-chaffed Red Cross) wheat 
were sown at intervals during the fall. These plats were 5 feet 
1 This bulletin deals with the disease previously designated take-all and so-called 
take-all which occurs in Illinois and Indiana. 
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