recently white oak cross-ties were used almost exclusively on Ohio rail- 

 roads. The extension of steam roads, and the replacement of worn and 

 decayed ties, together with the rapid development of electric roads, in 

 the past decade have practically exhausted the supply, of this wood, so. 

 that the railroads are now obliged to use less durable varieties of timber. 



Some of the larger railroad systems are co-operating with the United 

 States Bureau of Forestry in experiments to test the value of cross-ties 

 made of some of the less durable varieties of wood which have been 

 treated with preservatives. A few of the more progressive and far-see- 

 ing railroad managers, realizing the necessity, are turning their attention 

 to growing the western catalpa on a large scale, with the idea of meeting- 

 the future demands of their respective systems for cross-ties and tele- 

 graph poles. 



The black locust and hardy catalpa are deservedly popular because 

 of their many good qualities and would undoubtedly be planted more 

 extensively were it not for several important insect pests which prey 

 upon them. The former suffers the greatest injury. 



It is the aim of this bulletin to place the knowledge already obtained 

 concerning the insects affecting these trees before the grower in as con- 

 cise a manner as possible. Some of the insects enumerated are not at the 

 present time sufficiently numerous- to do serious damage, but the planting 

 of these trees on a large scale will greatly increase their food supply, 

 and furnish favorable conditions for a rapid increase in numbers ; hence 

 serious injury is likely to result. 



The portion dealing with the insects of the black locust was written 

 as a thesis for the degree of Bachelor of Science at the Ohio State Uni- 

 versity. It was prepared under the direction of Prof. Herbert Osborn,^ 

 whose valuable help and suggestions and kindness in permitting the use 

 of his library are hereby grafefuUy acknowledged. Thanks are also due 

 Mr. A. F. Burgess for the use of the field notes of the Division of Nur- 

 sery and Orchard Inspection, and assistance in preparing the whole for 

 publication. 



The portion dealing with the insects affecting the catalpa includes 

 the notes and observations made by several of the inspectors of this 

 Division during Ihe past year, and was added because of the close asso- 

 ciation of these two trees in an economic way. 



