312 OHIO EXPERIMENT STATION: BULLETIN 332 



base of the gall. When the slit is spread, the lice will be noted 

 within the gall. 



Life history and habits. — ^The cockscomb gall plant louse over- 

 winters as a shiny brownish egg within the protection of the rough 

 bark of the host. Coincident with the development of the foliage 

 the following spring, the eggs hatch and the young migrate to the 

 leaves where the gall is formed. During June, when these galls are 

 opened, the mother louse within will be found surrounded by num- 

 erous young. 



Later the mouth of the gall opens, allowing the escape of the 

 young, and at the same time large quantities of honey-dew are 

 released. 



Nature of work. — ^The distortion of the foliage caused by the 

 presence of the galls becomes a serious handicap to the tree in 

 instances of severe attacks. The dehydration of the leaf tissues by 

 the feeding lice and the annoyance to residents caused by the dis- 

 charge of quantities of honey-dew and the attending fungous growth 

 contribute still further to make the pest unwelcome. 



Distribution. — This insect is found in all parts of Ohio, and 

 widely distributed in other sections of the United States. 



Control. — Rarely is it advisable to attempt control measures, 

 since the presence o ' the insect rarely is discovered until the galls 

 are form.ed, and after that time the insects within are secure from 

 the action of sprays. With small, valuable trees, hand picking the 

 gall-bearing leaves might be practiced and the following spring the 

 trees might be sprayed with dormant strength lime-sulphur or mis- 

 cible oil in order to destroy any over-wintering eggs and thus con- 

 tribute toward the prevention of a recurrence of the outbreak. 



THE CATALPA MIDGE 



{Itonida catalpae Comstock) 



Description. — ^The catalpa midge in the adult stage is a fragile 

 two-winged fly. It measures about one-sixteenth Of an inch in 

 length, the Jegs are long and the body is light yellow in color while 

 the wings are dusky. The eggs are minute, elongate, whitish and 

 when deposited on the foliage are found in masses of 80 or more. 



The Jarva when mature is nearly one-eighth of an inch in length 

 and varies in color from pale-whitish to orange. It possesses the 

 ability to spring into the air to a height of several inches, the feat 

 being performed by bringing both ends of the body together in bow 

 fashion and suddenly straightening out. For illustrations of the 

 foregoing stages see Plate LIX, Figs. 1, 2 and 3, 



