THE CATALPA MIDGE. S 



leader which resulted in a crooked, forked stem. This insect seems 

 likely to assume considerable economic importance to nurserymen 

 and others growing catalpa trees." * 



Mr. Houser in Bulletin 194 of this Station says: "During the 

 early summer, the tender growing tips of the catalpa become swollen 

 and in time blacken at the point of injury. During the early part 

 of the season the injury isusually found three or four inches below the 

 tip, and at a lesser distance during late summer when the tree is 

 growing less rapidly. The tip above the injury dies. Following 

 the death of the tip in early summer, the next node below develops 

 one or more branches, and frequently a cluster of leaves, giving the 

 tree a bushy growth. The ultimate result, after continued top- 

 ping, is a stunted, crooked, forked growth." 



"An examination made last spring (1906") of all the twigs upon 

 IS three-year-old catalpa trees, revealed the fact that 49 percent of 

 the tips had been injured by the bud gnat." 



These blackened tips are generally full of larvae, the whole 

 pre'senting the same general appearance as does the interior of the 

 pods later in the season. It seems probable that injured spots in 

 the skin of the twigs are used as points of entrance, where these are 

 available, but it seems certain that entrance is often gained into 

 uninjured twigs. 



In July 1907, a circular letter accompanied by a small folder of 

 illustrations, entitled "Three Catalpa Troubles," was sent out from 

 the Department of Entomology of the Ohio Experiment Station to 

 several hundred catalpa growers in Ohio, requesting reports on the 

 kinds of injury described and illustrated. Two of the forms of 

 injury due to the catalpa midge, viz., terminal bud damage and 

 leaf-spot were among the subjects of inquiry. Of the growers 

 reporting, 119 had not suffered from either form of injury, so far 

 as they were able to discover, while 107 had observed one or both 

 forms. About one-third of these reporters (37) had noticed the 

 terminal injury without finding any leaf-spot; 33 found leaf-spot 

 conspicuous without any injury to the buds, while 37 found both 

 forms of damage occuring conjointly. 



3 Professor Comstock's description of the third form of 

 damage is as follows: "In the early part of August the unripe and 

 uormally green pods of the Indian bean {Catalfa bignonotdes) upon 

 the Department grounds, at Washington, were noticed mmany 

 cases to have partly turned brown in a strange manner; one-half or 

 more of the pod remaining green, while the remainder appeared to 



* Bulletin 7 of Div. Nursery and 0«d.ard Inspection, Ohio Department of Agriculture. 



