Summary concerning measures, other tlian burning, for destroying 

 the beetles in hibernation. — As is shown, none of the immediately fore- 

 going group of materials (see table) even approached satisfactory con- 

 trol save kerosene emulsion. This proved veiy effective at 10 per cent. 

 strength, and could probably be used with safety. The cost of treating 

 with kerosene emulsion would be approximately $20 an acre and with 

 scalecide $30 an acre. 



BURNING IN HIBERNATION 



Without use of blow torch. — The possibility of burning the apple 

 flea- weevil in its winter quarters has probably suggested itself to every- 

 one having any experience with the pest, and some of our best results 

 in the search for an adequate control have been obtained by this means. 

 Two different methods were used : burning oft the trash and leaves in 

 dry weather, and burning with a torch. Success in burning without a 

 blow torch depends largely on the character of the refuse under the 

 trees and its condition as to moisture content. Two tests were made in 

 the Braden orchard at Olney, 111., with results as shown in the accom- 

 panying table. 



Another experiment with surface burning was made in early April, 

 1920, in the orchard of the Delaware Apple Company, at Delaware, O. 

 This orchard was 10 to 12 years old and had been in grass for several 

 years, so that a well-matted sod had developed. When the burning was 

 done the trash was fairly dry, particularly between the tree rows, and 

 dry enough under the trees so that the fire burned a surface layer up 

 to the trunk though it did not consume all the fallen leaves. Immedi- 

 ately under the trees, however, enough burning was done to cause 

 noticeable injury to the lower branches, as the low-headed type of 

 pruning had been practiced. No noticeable decrease in the number of 

 weevils in this section was found after the brood emerged ; indeed the 

 seasonal injury was. if anything, greater, for the burning of the surface 

 cover had exposed the beetles to the spring sun, thus bringing them out 

 of hibernation a few days earlier than on the unburned section. As a 

 result, they attacked the foliage with telling effect as it began to expand. 



With blow torch. — This type of burning has proven, under some 

 conditions, the most effective of the control measures tried. If the or- 

 chard was partly cultivated, thus forcing the beetles to hibernate on a 

 comparatively small area under the trees, the result was excellent, but 

 if the orchard was in sod, affording hibernating quarters throughout 

 the area occupied by the trees, it was found to be of little value. 



Two kinds of torches were used for this work, one burning kero- 

 sene and one gasoline. The kerosene torch, of a type commonly used 

 for melting asphalt in paving streets, proved tiie more effective. It is 

 made by the Houck Manufacturing Co., and consists of a 5-gallon 

 tank equipped with an air-pump and gauge for supplying and registering 



