August, '21] HAMILTON: BOX MIDGE CONTROL 361 



Control Methods 



Attempts have been made to control the insect under a variety of 

 methods by different workers. Som.e of these include spraying with 

 arsenical poisons to kill the adults. This work was entirely without 

 results as the m-outh parts of the adults appear rudimentary and it is 

 probable that they take no food after em.erging. Dusting with sul- 

 fur, road dust and other dusts has been tried in France with som.e suc- 

 cess. The dust a:ts as a mechanical barrier and repels the adults 

 when laying their eggs. Since it does not kill the insect but drives it 

 to unprotected places, its use is not desirable if other m.ethods for con- 

 trolling it can be found. Spraying with a number of contact sprays 

 to kill the eggs, larvae, pupae, ard adults has been tried with varying suc- 

 cess. The best results were secured by spraying when the adults were em.erg- 

 ing. Fumigating dtiring the larval stage with potassium, cyanide, 

 carbon disulphide, amm.onia, and other gases has given som.e control 

 in laboratory- experiment.'^. There are no records of its having been 

 tried under field conditions. The only gases whi.:h killed the larvae 

 without injuring the plants were hydrocyanic acid gas and carbon di- 

 sulphide. Spraying with molasses to entangle the adults as they 

 emerge and when laying eggs has given prom.ising results. 



The work reported upon here consists of laboratory and field exper- 

 iments with molasses as a sticker, various contact sprays and fimiiga- 

 tion with potassium, cyanide and carbon disulphide. 



Preliminary Experiments to Control the Adults 



On May 20th, 1920, sections of an infested box wood hedge at Bal- 

 tim.ore, Maryland, were sprayed with the following materials: 



Lot Xo. 1. Karo syrup 1 gallon, water 1% gallons, e.xtract of pyrethrum 10 cc. 



The material spread well and upon drying gave a uniform sticky surface on new 



and old leaves. 

 Lot No. 2. Karo syrup 1 gallon, water 5 gallons, extract of pyretlirum 20 cc. This 



spray did not spread quite as well on new leaves as Lot No. 1. 

 L<^jt No. 3. Karo syrup 1 gallon, water 5 gallons, copper sulphate 2 ounces. (The 



copper sulphate was added to determine whether it would prevent mold from 



growing on the syrup). This lot spread the same as Lot No. 2. 

 Lot No. 4. The same as Lot No. 3 except that dry pyrethrum was dusted on after 



spraying. Spread the same as Lot No. 2. 

 Lot No. 5. The same as Lot No. 3 except that Corona dusting tobacco was dusted 



on after spraying. Spread the same as Lot No. 2. 

 Lot No. 6. Soluble pine tar diluted one part to ten parts of water. Spread very 



well on new and old leaves. y 



