UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1182 
Washington, D. C. 
December 12, 1923 
THE IMPORTED PINE SAWFLY. 1 
By William Meddleton, 
Scientific Assistant, Forest Insect Investigations. 
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CONTENTS. 
Page. 
Introduction 1 
Descriptions 1 
Life history and seasonal history 7 
Effect of meteorological conditions 14 
Parthenogenesis 15 
Page. 
Parasites 16 
Hosts 17 
Distribution in the United States 20 
Economic importance 20 
Control 21 
INTRODUCTION. 
A European insect, the imported pine sawfly, 2 has recently been 
found defoliating young pine trees in nurseries and on estates in cer- 
tain of the New England and North Atlantic States. 
This bulletin contains descriptions of the principal stages of the 
species and some information on its life history, host plants, distri- 
bution, and importance, together with a brief discussion of its control. 
The data presented are based on investigations of the sawfly con- 
ducted at the eastern field station of the Forest Insect Investigations, 
Bureau of Entomology, at East Falls Church, Va. The studies began 
\vitri the receipt of material in August, 1915, and continued until the 
spring of 1919, when the last adults emerged in the cages. 
Inasmuch as the species was an introduced and dangerous one 
which had not become well established in this country, great care was 
exercised in the cage work, in order to prevent its escape. A special 
double- walled, screen-wire insectary was constructed to which en- 
trance was had only through a vestibule, and all the experiments were 
performed on young trees transplanted into this inclosure. 
DESCRIPTIONS. 
The following descriptions have been prepared, so that this species 
can be recognized in its principal stages. Those of the adult are by 
S. A. Rohwer. 
1 This bulletin was prepared under the direction of ?. A. Rohwer, to whom the author is indebted for many 
helpful suggestions in conducting the investigations. The descriptions of the adult insects are by Mr. 
Rohwer. The majority of the material from which these studies were made was obtained from Dr. W. E. 
Britton, State entomologist of Connecticut. 
3 Liprion simile Hartig, order Hymenoptera; suborder Chalastogastra; superfamily Tenthredinoidea; 
family Tenthredinidae; subfamily Diprioninae. 
53373— 23— BuU. 11S2 1 
