AgUUSt, '21 J HAMILTON: BOX MIDGE CONTROL 365 



twigs fumigated with potassium cyanide at the rate of one and two 

 ounces per thousand cubic feet of air space for two hours killed approx- 

 imately 70% of the larvae, without any injury to the leaves. When 

 the time was increased to six hours, using the sam.e strengths, all the 

 larvae were killed but considerable wilting of the leaves resulted. Car- 

 bon disulphide at the rate of 20 drops to 720 cubic inches for 70 min- 

 utes killed 60% of the larvae. The dose was increased to 40 drops and 

 85% of the larvae were killed. No injury resulted to the plants in 

 either case. In the check twigs 30% of the larvae were found dead. 

 The results in the different fumigation experiments varied considerably 

 and considering the attending danger it would probably not be advis- 

 able to fimiigate for control under field conditions. 



Summary 



1. The adults may emerge from the middle of May to early in June. 

 They commence laying eggs soon after emerging and then die. 



2. The best time for controlling the insect is while the adult is emerg- 

 ing from the pupal skin. 



3. Spraying with molasses, diluted one part to three parts of water, 

 gave the bert results, entangling the ro.ajority of the adults as they 

 emerged or before laying eggs. The under surface of the old and 

 new leaves must be thoroughly covered with the m-olasses spray, 

 and the spraying m.ust be repeated often enough to keep them 

 sticky. 



4. Laboraton,^ experiments, spraying once with Black Leaf 40 and 

 once with Black Leaf-resinate, diluted one part to 500 parts of 

 water, killed approximately 80% of the adults before they emerg- 

 ed successfully. A killing effect was noted four and five days 

 after spraying. Spraying should probably be repeated at inter- 

 vals of not less than four or five days during the emerging period. 



