UNITED STATES DEPARTMENT OF AGRICULTURE 
^W*W4. 
BULLETIN No. 787 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Washington, D. C. 
June 9, 1919 
PROTECTION FROM THE LOCUST BORER. 
By F. C. Craighead, 
[Specialist in Forest Entomology, Forest Insect Investigations. 
CONTENTS. 
Page. 
Introduction 1 
Historical 2 
Observations by tbe writer 2 
Investigations and experiments 3 
Natural growth in tbe vicinity 
of Falls Church, Va 3 
Plantations along the Pennsyl- 
vania Railroad 5 
Condition of tree necessary for 
borer attack _ _ 8 
Page. 
How to recognize trees containing 
no borer defects 9 
Character of growth of uninfested 
stands . _. — _ 9 
Conditions under which locust can 
be grown 10 
Control 11 
A method of handling severely 
damaged plantations 11 
Treatment of shade trees '. 11 
Literature cited 12 
INTRODUCTION. 
The increasing value of black or yellow locust 1 for many pur- 
poses, and especially the recent demand for sound locust pins or tree- 
nails in the construction of wooden ships, render its protection from 
insect damage important. 
In addition to the natural growth of locust in forests, farmers' 
woodlots, and abandoned fields, many attempts have been made to 
grow it on a commercial scale in plantations. These attempts in most 
cases have resulted in failure, owing to the serious damage to the 
wood and frequently the destruction of the trees caused by the locust 
borer. 2 The fact, however, that in natural growth and occasional 
plantations practically no injuries from the borer are found, while 
in other cases the trees are ruined for commercial purposes or killed 
outright, has led the writer to make a thorough investigation of the 
problem to ascertain the cause of the occasional immunity from borer 
injury. 
As a result of these investigations, it appears practically certain 
that plantations of this tree can he protected successfully from 
1 Robinia pseudacacia L. 
106358°— 19 
2 Cyllene robiniae Porst. 
