In the preparation of this bulletin several references were found of 

 insects feeding upon the "locust," and where it was not clear which 

 species was referred to they were not included. The references given 

 in the bibliography which follows each insect are those which have a 

 direct bearing upon it as an enemy of the black locust. In some cases 

 the description of the insect in one or more of its stages, notes on its life 

 history or its natural enemies, are included. 



Dyar's List of North American Lepidoptera was used as a guide in 

 correcting the specific names of the insects belonging in that order and 

 in referring them to their proper genera. In Coleoptera Henshaw's List 

 of the Coleoptera of America, north of Mexico, was followed, and Mrs. 

 M. E. Fernald's catalogue of the Coccidae of the World was consulted 

 in naming and arranging the scale insects. 



THE LOCUST BORER. 

 Cyllene robimae Drury. 

 Ofder Coleoptera; Family Cerambycidae. 



This insect is one of the most destructive enemies of the locust tree. 

 Its attack is so insidious, and the injury done is so inconspicuous until 

 the damage is complete, that it is not often noticed by the casual observer, 

 ^nd fine trees or plantations may be almost ruined before the owner knows 

 that any injury is being done. So far as the writer's personal observa- 

 tions go, the injury is greater in single trees planted for ornamental 

 purposes and plantations of considerable size than in natural forests. 

 This is probably due to the fact that, in ihe latter case, the injury is 

 distributed over a large number of trees, and therefore less attention is 

 given to any one. In many parts of the state where the trees are plenti- 

 ful and grow thriftily the damage is less apparent, as the growth is rapid 

 enough to heal over the injury caused by the larv^. 



In this state a black locust tree without one or more dead patches 

 on its trunk, caused by the workings of these insects, is the exception 

 rather than the rule. The writer has seen plantations in which the trunks 

 of nearly all the original trees had been killed by these larvae, and sprouts 

 thrown up from the lower part of the trunks had been in turn destroyed ; 

 and in extreme cases the same fate had overtaken the second set of 

 sprouts, none of them growing larger than three inches in diamerer and 

 being so thoroughly tunneled as to be worthless, except for firewood. 



The present geographical distribution of this pest is practically the 

 same as that of its host. Forster mentions this insect as an enemy of the 

 locust, in New York, about 1766, and it has gradually advanced west- 

 ward and southward with the spread of the tree. It was first noticed 

 in large numbers on the black locust trees at Rock Island, 111., in 1863 

 and during the two following years completed the destruction of nearlv 

 ■all the locust trees in that city. 



