INSECTS AND INSECTICIDES. 11 



appearance, thoroughly eradicate it. It is a small brownish- 

 black insect and exists in the wingless as well as in the winged 

 form. It attacks the roots as well as the foliage, and this 

 makes it all the more diffi- 

 cult to combat. The branch 

 form is readily controlled 

 by the use of kerosene 

 emulsion or the whale-oil 

 soap wash, using the sum- 

 mer formula; but, so far, 

 no wash or remedy has 

 been found to give perfect FlG 6 Black p ~ ch Aphis (Aphis 



results On the root form, perslcx-niger). 



only partial relief having 



been obtained by the use of a diluted kerosene emulsion, used 

 around the base of the tree and applied during or just before 

 a rain. This allows the water to carry the emulsion to the 

 infested parts. Tobacco dust, as recommended for the root 

 form of woolly aphis, will also give partial relief. 



Hop Louse (Phorodon humuli). The following is recom- 

 mended, to be applied as a spray: 



Whale-oil soap 7 pounds. 



Quassia chips .-_ 8 pounds. 



Water 100 gallons. 



Soak the quassia chips for eight or nine hours in hot water. 

 Dissolve the whale-oil soap, by boiling, and mix the two 

 liquids, adding enough water to make 100 gallons. 



The best machine to use is the Knapsack sprayer with a 

 Cyclone or Vermorel nozzle, using a very fine spray and 

 applying it to the under side of the foliage. 



CANKER OR MEASURING WORMS, TUSSOCK MOTH, LEAF- 

 ROLLERS, AND OTHER LEAF-EATING CATERPILLARS. 



For these pests the following is recommended: 



Arsenate of lead 12 pounds. 



Water 200 gallons. 



Rub up the desired quantity of arsenate of lead into a 

 smooth, thin paste in a small amount of water, and pour into 

 the spraying tank or barrel. Keep the mixture well stirred 

 and use a fine spray with plenty of pressure. A warm, sunny 

 day should always be selected. 



