BULLETIN No. 250 ‘ 
3 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Washington, D. C. PROFESSIONAL PAPER Jnly 24, 1915. 
FOOD PLANTS OF THE GIPSY MOTH IN AMERICA. 
By F. H. MosHer, 
Entomological Assistant, Gipsy Moth and Brown-Tail Moth HisGangebions 
CONTENTS. 
Page. Page 
Scope of the investigation__________ 1 | Classification of food plants____-___ 33 
Equipment of the laboratory__---—-. 4 | The forest problem______4-_______~ 35 
Methods of conducting laboratory ex- Recommendations for orchard prac- 
02 BATTEN Sp eS eg 4 tice) 22 so Ce a ee ae 35 
Difficulties in conducting the experi- Mie :elity, problemas ss ees a ae 36 
Fa EN SE aa i ae 5 | Index of food plants used in experi- 
Kood-plants testedi2--. =... 2. 5 TUNG T NS 36 
Combination-tray experiments —_~-~~ 27 
SCOPE OF THE INVESTIGATION. 
Since the time the gipsy moth (Porthetria dispar lL.) became 
abundant enough in Massachusetts to require treatment in order to 
prevent the defoliation of trees and shrubs the question of its favored 
food plants has been under consideration. 
During the period from 1890 te 1990 an attempt was made by the 
State of Massachusetts to exterminate this insect, and a study of the 
different species of plants upon which the caterpillars would feed was 
made prior to 1896 and published that year by Forbush and Fernald 
in their report on the gipsy moth. These experiments were carried 
on with nearly full-grown caterpillars, a small number being confined 
‘in a jar with each food plant. If no feeding was noted in three days 
the experiment was repeated with other caterpillars, and if the same 
result was secured for this lot the food plant was considered unfa- 
_vored by the caterpillars. As a result of these experiments 477 
species of trees, shrubs, and plants were tested, and 458 of these were 
Notp.—This bulletin reports a series of investigations conducted in 1912, 1913, and 
1914 to determine the favored food plants of the gipsy moth. The subject is of interest 
to entomologists and to State authorities engaged in the fight against the gipsy moth in 
‘the northeastern States. 
9§2719° —15——1 
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