194 OHIO EXPERIMENT STATION: BULLETIN 194 



The Elm Leaf Beetle, This insect was first discovered within 

 Galerucella luteola Mull, the borders of this state by Mr. G. A. 



Runner of the State Nursery and Or- 

 chard Inspecting- Department. It was found during- the summer of 

 1904 feeding- upon the elms located in the grounds of the National 

 Cash Register Co., Dayton, Ohio. Subsequent examinations re- 

 vealed its presence in a number of parts of the city. 



In July, 1907, the writer made a visit to the city, and found the 

 elms in some sections to be in very bad condition. At that time, as 

 far as the writer was able to learn, work of combatting' the insect 

 had been commenced in three places only, one being- on the grounds 

 of the Cash Register Company, where arsenical sprays had^been 

 applied, and the remaining- two were near the center of the town, 

 where some work in banding- had been executed by Mr. C. F. Harbi- 

 ,son in cooperation with the Agricultural Experiment Station. 



Because of the absence of the chief gardener, in whose charg-e 

 the work had been placed, the writer was unable to obtain a very 

 definite idea of what had been accomplished towards controlling 1 the 

 insect on the grounds of the Cash Register Company. 



The plan worked upon by Mr. Harbison was to band the trees 

 with tanglefoot and burlap when the larvae first began to descend, 

 and to examine the bands at frequent intervals throughout the 

 season, destroying- all larvae or pupae that collected on or under the 

 bands or at the base of the tree. Although most carefully executed, 

 the banding- process was only partially successful in controlling- the 

 pest. 



The elm leaf beetle is well distributed in the eastern states, and 

 now annually ruins great numbers of shade trees. The green and 

 black striped beetles, not over ^ inch in length, pass the winter in 

 the adult stage in some sheltered place. With the coming of spring 

 they leave their shelters and begin feeding upon foliage of the elm. 

 Soon the eggs are deposited on the under sides of the leaves and 

 within a few days the larvae appear. They feed upon the under- 

 sides of the leaves, leaving the vein work and epidermis above. Soon 

 the injured portions of the leaf die and the leaves appear as illus- 

 trated in Plate 15, Fig. 1. 



The grubs become full grown in from 2 to 3 weeks, or possibly 

 longer, depending upon the weather conditions. At the conclusion 

 of larval development the insects crawl about and either pupate in 

 the crevices of the bark or in some nearby shelter. Often they may 

 be seen lying helpless in considerable quantities at the base of the 

 tree. 



It is quite likely that only two generations occur annually in Ohio. 

 Elms only are attacked. 



