UNITED STATES DEPARTMENT OF AGRICULTURE 
j| BULLETIN No. 808 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
February 24, 1920 
STUDIES ON THE LIFE HISTORY AND HABITS OF THE 
JOINTWORM FLIES OF THE GENUS HARMOLITA (ISO- 
SOMA), WITH RECOMMENDATIONS FOR CONTROL. 1 
By W. J. Phillips, 
Entomological Assistant, Cereal and Forage Insect Investigations. 
CONTENTS. 
Page. 
Introduction 1 
Species infesting the grain crops 2 
The wheat jointworm (Harmo- 
lita tritici Fitch) 2 
The wheat straw-worm (H. 
grandis Riley) 5 
The wheat sheath-gall joint- 
worm (H. vaginlcola Doane)_ 8 
The barley jointworm (H. hor- 
dei Harris) 11 
The rye jointworm (H. secalis 
Fitch) 13 
The rye straw-worm (H. websteri 
Howard) 14 
Species infesting the cultivated 
grasses 15 
The timothy straw-worm (H. al- 
bomaculata Ashmead) 15 
The orchard grass straw-worm 
(H. dactyUcola Phillips & 
Emery) 16 
The blue-grass jointworm (H. 
captiva Howard) 16 
Page. 
Species infesting the cultivated 
grasses — Continued. 
The blue-grass straw- worm (H. 
poae Phillips & Emery) 17 
The festuca jointworm (H. fes- 
tucae Phillips & Emery) 18 
Species infesting wild grasses 19 
Harmolita maculata Howard 19 
H. atlantica Phillips & Emery 19 
H. agropyrophila Phillips & 
Emery 20 
H. elynri French 20 
H. ■elymieola Phillips & Emery_ 21 
H. elymivora Phillips & Emery_ 21 
H. rufipes Phillips & Emery 21 
H. Jiesperus Phillips & Emery 22 
H. elymophthora Phillips & 
Emery 22 
H. ovata Phillips & Emery 22 
Species whose biology is unknown- 23 
Control measures 23 
Literature cited 26 
INTRODUCTION. 
Owing to the chaotic condition existing until recently in the classi- 
fication of the genus Harmolita (Isosoma), it has been practically 
impossible to obtain specific determinations, and this fact has largely 
prevented economic workers from undertaking detailed life-history 
studies of the various species. Some members of this genus are of 
great economic importance, the losses directly traceable to them 
1 The writer wishes to acknowledge his indebtedness to various members of the branch 
of Cereal and Forage Insect Investigations who furnished material from time to time for 
breeding work, but more particularly to Messrs. W. T. Emery, Philip Luginbill, and 
T. H. Parks, and to Dr. Henry Fox, $vho have been associated with him and have ren- 
dered valuable assistance in breeding, and to Mr. A. B. Gaban for kindly criticisms of 
the manuscripts. 
132861°— Bull. 808—19 1 
