August, '21] 



HAMILTON: BOX MIDGE CONTROL 



363 



second application, making a total of 43 gallons. At 50 cents a gal- 

 lon tnis gave a cost of $21.50 for materials. 



A final count after the adults had all emerged gave an average in- 

 festation of 2 eggs per leaf in the sprayed hedge and 10.1 per leaf ia 

 the unsprayed hedge. Tiiis is an apparent control of 80%. As hign 

 as 68 eggs were found in a single leaf in the unr prayed hedge. Had 

 the first spray been appHed before the adults began to emerge, approx- 

 imately a complete control might have been secured. To secure the 

 best restdts it will probably be necessary to sprav three times during 

 the emerging" period and oftener if it rains. The syrup did not mould 

 and remained quite sticky until the 10th of June when it was washed 

 off by a heav}^ rain. 



Laboratory Experiments with Contact Sprays 



Branches of the infested box wood plants were secured at Baltimore, 

 brought to the laboratory and placed in water. After spraying with 

 the desired material they were placed outdoors in the field insectary. 

 Ever\^ effort was made to keep the twigs fresh as it was found that the 

 larvae soon died in wilted or old leaves. Spraying experiments were 

 started diiring the pupal stage and continued through the emerging 

 and egg laying periods and up to late fall. Table No. 1, sprayed May 

 18th, gives some of the materials tested and the results sectu-ed. 



