UNITED STATES DEPARTMENT OF AGRICULTURE 
Contribution from the Bureau of Entomology. 
L. C. HOWARD, Chief. 
Washington, D. C. Vv May 31, 1920 
CHRYSANTHEMUM MIDGE.'! 
By C. A. Western and H. L. Sanrorp, Collaborators, Tropical and Subtropical Fruat 
Insect Investigations. 
CONTENTS. 
Page. | Page 
Generalidescripiion: = 222 <3 .52.02 2-2 2425..2-% i, waite Mistoryandshabpitsss- csc so. 35 vse 7 
ISBGTACAN se ok sate ed - Sennen. ose Be Zar Naturalenemicss i=. 9- ote. oe a ee 13 
Distribution in the United Statesand Canada.. 3 | Experimentsin control....................-.-. 14 
WanletiesialiCChed ax < He. Saat oa cc ajsceccs cesses 4 | Summary of control and recommendations.... - 21 
Heawomicimportance | 272.655. 22. 2.26.22 2. - 4e)) (Preventive measuLess-ss.2-2 co 8-026 tee Soeeels 2 
Meckwical description: o.s6 on eee se.- 4-5 - 6, j-cditerature Cited se snonc. ee 2 Sos secick cde See - See 
GENERAL DESCRIPTION. 
The chrysanthemum midge, Diarthronomyia hypogaea (F. Léw), 
is a European insect which gained entrance into the United States 
a few years ago and since then has been reported as injurious from 
widely separated localities in this country and Canada. 
When chrysanthemums are infested by this midge, the attention 
of the casual observer is most likely to be drawn to the presence of 
galls. These galls occur on the leaf, stem, or flower head of the 
chrysanthemum plant. (See Pl. I, BandC.) After the larve hatch 
from the orange-colored eggs, which are deposited by the adult 
female on the surface of tender tips and new growth, they bore their 
way into the tissues, thereby giving rise to the galls. 
The galls are cone-shaped and generally project obliquely from the 
surface. The length of the gall when fully developed is about one- 
1 The account of the chrysanthemum midge contained in this bulletin is the result of an investigation 
which was undertaken with the intention of providing further data on the life history and habits of this 
insect, as well as more satisfactory means of control. The preliminary life-history studies which were 
Started in February, 1917, by A. D. Borden, of the Bureau of Entomology, were subsequently taken up 
by H. F. Dietz, of the Federal Horticultural Board. Further studies on life history and control were 
inaugurated and carried to completion by the writers as a result of the many inquiries for advice as 
well as the outbreaks reported during the chrysanthemum season of 1918 and the spring 0f 1919. During 
the entire period the work has been under the constant supervision of E. R. Sasscer, chief inspector of the 
Federal Horticultural Board and collaborator of the Bureau of Entomology. 
150054°—20—Bull. 833-1 
