﻿*ITED STATES DEPARTMENT OF AGRICULT1 



| BULLETIN No. 1137 ™ 



|*jJr* Joint Contribution from the Bureaus of Plant Industry and *\£"i 



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 



Comparison between the symptoms 

 of wheat rosette and those caused 

 by the wheat stem maggot 



Conclusions 



Literature cited 



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 larvss 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 rosstte 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 tate-all and so-called 

 take-all which occurs in Illinois and Indiana. 



23244—23 



