THE CATALPA MIDGE. 13 



way, a straight skyward growth is forced and, although the young 

 trees start off with crooked trunks due to successive forkings, 

 caused by terminal injury, after a few years the trunks will have 

 become quite straight. After the trees have attained an age of five 

 or six years alternate trees can be cutout, if necessary, and the 

 trees may be trusted after this age to grow fairly straight. 



ACKNOWLEDGEMENTS. 



I am indebted to Messrs. Howard, Felt, Coquillett and Craw- 

 ford for examinations and reports on various specimens of insects 

 submitted to them during the progress of the investigation; to 

 Messrs. J. S. Houser, W. H. Goodwin and H. T. Osborn for numer- 

 ous field observations and laboratory records; to the Department of 

 Cooperative Experiments of this Station for assistance in collecting 

 data from the Ohio growers of catalpa; and to Messrs. Goodwin and 

 Houser for the illustrations given. To all of the foregoing, I 

 express my thanks. 



